Novartis AG & Anor v Johnson & Johnson Medical Ltd (t/a Johnson & Johnson Vision Care) & Anor

This is a patent infringement action concerning extended wear contact lenses, that is to say lenses which may be left in the eye overnight or even for several days. The first and second claimants are respectively the proprietors and exclusive licensees of European Patent UK No 0,819,258 (“the Patent”) and they contend that the defendants have infringed the Patent by selling certain contact lenses called Acuvue Oasys (“Oasys”) in the United Kingdom. The defendants deny infringement and counterclaim for revocation of the Patent contending that it lacks novelty, is obvious and is insufficient.

The Patent is somewhat unusual in that it claims contact lenses partly by reference to certain desirable characteristics such as ophthalmic compatibility, corneal health and wearer comfort, and partly by reference to physical parameters such as oxygen transmissibility and ion permeability. This manner of claiming lies at the heart of many of the disputes as to the validity of the Patent and whether it is infringed.

The Patent claims first, second and third priority dates. The defendants say the claims to the first and second priority dates (4 April 1995 and 19 May 1995) are obviously unsustainable because they contain no reference to the parameter of ion permeability or the techniques by which it is to be measured. These were introduced for the first time in the third priority document which was not filed until 8 December 1995. The application for the Patent itself was filed on 22 March 1996.

The issue over priority forms the basis of the first substantive attack on the Patent. The defendants say that the Patent lacks novelty under section 2(3) of the Patents Act 1977 (“the Act”) in the light of two applications WO 96/31791 (“Hopken”) and WO 96/36890 (“Domschke”) in the name of Ciba-Geigy AG, the first claimant’s predecessor in title to the Patent. These applications contain a disclosure and description of contact lenses made of two classes of materials, B (in the case of Hopken) and C (in the case of Domschke), which also appear in the Patent. Hopken claims priority from the same first priority document as the Patent and Domschke claims priority from the same second priority document. However, the defendants say that, unlike the Patent, the Hopken and Domschke claims to priority are good because they do not characterise the lenses they describe by reference to ion permeability but only by reference to polymer chemistry. It follows, say the defendants, that if, as the Patent suggests, some or all of the lenses they describe fall within the claims of the Patent, then the claims must be anticipated.

The second attack on the Patent is one of lack of novelty and obviousness based on the common general knowledge and three other earlier citations. It is contended that WO 91/04283 (“Chang”) and WO 93/09154 (“Lai”) disclose contact lenses which satisfy at least claim 1 of the Patent. To support these allegations lenses made in accordance with example 3 of Chang and example 4 of Lai have been made in experiments performed for the purpose of these proceedings. Measurements have been taken of their oxygen transmissibility and ion permeability and they have also been the subject of clinical tests.

The third citation is US 4,260,725 (“Keogh”) which the defendants again contend discloses contact lenses falling within at least claim 1 of the Patent. In this case the defendants have not performed experiments because they say it is apparent on the face of the specification that the lenses satisfy the oxygen transmissibility and ion permeability requirements of the claims and because the specification reports that the lenses were satisfactorily tested in the eyes of monkeys for a period of 24 hours.

The final attack on the Patent is one of insufficiency. Although I mention it last, it developed in the light of the evidence into a fundamental assault on the whole specification. In short, the defendants contend that the teaching of the Patent does not provide sufficient information for the person skilled in the art to make contact lenses within or across the range of the claims without undue experimentation. Rather than providing assistance as to how to work across the generality of the claims to achieve lenses having the desired properties, it sets a puzzle, not least because merely having the oxygen transmissibility and ion permeability characteristics required by the claims is plainly not sufficient to produce lenses which satisfy all the other requirements such as ophthalmic compatibility, corneal health and wearer comfort over a period of extended wear.

Infringement is also hotly contested. The key claims alleged to be both independently valid and infringed are 1, 8, 11 and 24. The principal issues are these:

Claim 1: do the accused lenses satisfy the oxygen transmissibility requirement of the claim?

Claims 8 and 11: do the accused lenses have co-continuous phases (claim 8) or pathways (claim 11)?

Claim 24: do the accused lenses have a surface which is more hydrophilic than the core?

I heard evidence from no fewer then nine expert witnesses over the course of the trial.

On behalf of the claimants, expert evidence was given by Dr Michael Port, Professor Gerhard Koßmehl and Professor Ian Hamley.

Dr Port is a Fellow of the British College of Optometrists and a Fellow of the British Contact Lens Association. He worked in the contact lens field for over 40 years from 1964 until his retirement in 2007. From 1987 to 2007 he was a senior lecturer in the Department of Optometry and Visual Science at City University, London. Prior to that he practised for 15 years as an optometrist, initially in private practice and then in the Contact Lens Department of Moorfields Eye Hospital, London. He was formerly the chair of the contact lens committee of the British Standards Institute and is a UK principal expert on the contact lens care committee of the International Standards Organisation. He has lectured and published extensively in the contact lens field and has carried out research for a large number of contact lens manufacturers over the last 20 years.

Dr Port gave his evidence in a measured and careful manner. I found him to be knowledgeable about clinical matters but he has never worked in the research and development department of a contact lens company, did not read patents and has not been involved in research into silicone hydrogel materials. Subject to these qualifications, I found his evidence to be clear and helpful.

Professor Koßmehl is an expert in the field of polymer chemistry. He was Professor of Organic and Macromolecular Chemistry at the Free University of Berlin, Germany from 1970 until his retirement in 1997. His work had a particular focus on materials for use in contact lenses in that from 1977 he worked in conjunction with and as a consultant to a manufacturer of contact lenses called Titmus Eurocon. This company was acquired by Ciba-Geigy AG in 1983 and made a part of CIBA Vision. Professor Koßmehl’s primary role was to synthesise novel materials, particularly polysiloxanes, fluorinated polymethacrylates and hydrogels. His involvement in the collaboration ceased in June 1995 and he played no part in the SEE3 project which ultimately resulted in the Patent.

Professor Koßmehl has an engaging personality and gave his evidence in a direct and open manner. He clearly had a wide general experience of the materials used in the manufacture of contact lenses in the years leading up to the priority date. However, he had no direct experience of synthesising silicone hydrogels and his experience of working in the manufacture of lenses appeared to be limited to his collaboration with Titmus Eurocon and CIBA Vision. There was one other unusual aspect of the evidence of Professor Koßmehl upon which I must comment. He adopted in an annex to his report a body of observations of a Professor Mays, who has apparently given evidence on behalf of the claimants in parallel proceedings in other jurisdictions, and he did so without acknowledgement. I do not consider this to be a desirable course. The opinions of an expert should be his own and the course taken by Professor Koßmehl must carry with it a considerable risk his opinions have been influenced by those of Professor Mays.

Professor Hamley is Diamond Professor of Physical Chemistry and Head of Physical Chemistry at the University of Reading. His research interests are focused on soft materials including polymers and in that regard his research activities range from peptide and block copolymer synthesis through to physico-chemical characterisation of self-assembly mechanisms and structures in these and related systems and fabrication of nanostructured materials. His project work has included studies of microphase separation in such materials and has been conducted in collaboration with physicists, chemical engineers and materials scientists.

Professor Hamley was a knowledgeable and fair witness and I found his evidence of great assistance. There are, however, two matters I should mention. The first is that he had a particular experience of a technique called Small-Angle X-ray Scattering (“SAXS”) and a related technique involving neutrons (“SANS”). The claimants’ notice of experiments suggested they would be relying on experiments using SAXS to establish infringement but these were abandoned at about the time Professor Hamley was instructed. In the course of cross examination he accepted that SAXS and SANS can reveal information about the morphology of a sample, an issue which arises in relation to the allegation of infringement of claim 8. But apparently he was advised by the claimants that small angle scattering was not to be a part of the case. He did, however, give evidence about and expressed opinions based upon results obtained using transmission and scanning electron microscopy (respectively “TEM” and “FEGSTEM”) and a technique called energy-dispersive X-ray analysis (“EDX”), despite not being as familiar with these techniques as Dr Bradley.

In addition to their three experts, the claimants called evidence from three witnesses of fact. Dr Nicolson, one of the named inventors of the Patent, gave evidence about the accolades received by the invention from the industry, the problems associated with lenses made from two other classes of materials described in the Patent, specifically Alsacon (made of material A) and Podium (made of material D) and the accuracy of certain ion permeability (Ionoflux) measurements recorded in the Patent. I have to say that following cross examination, I gained a somewhat different impression of these matters to that conveyed by Dr Nicolson’s statement. Nevertheless, the evidence he gave under cross examination was clear and frank and I have no doubt given honestly.

Dr Walther gave evidence as to how certain electron micrographs were taken in Sheffield. He was a clear and careful witness and, rightly, no criticism was made of the way he gave his evidence.

Finally, Mr Chyatte, General Counsel of the second claimant, gave evidence about the state and size of the market and the success of the claimants’ extended wear contact lenses called Focus Night and Day (“FND”) and O2OPTIX which, he explained, are based upon material B of the Patent. He also gave evidence about the extended wear contact lenses made by the claimants’ competitors. Of these the major manufacturers are Bausch & Lomb (“B&L”), whose PureVision lens is sold under licence from the claimants, CooperVision, whose Bioinfinity lens is also sold under licence from the claimants and the defendants with their allegedly infringing Oasys lens. No criticism was made of him as a witness, nor could it have been.

On behalf of the defendants, expert evidence was given by Professor Paul Valint, Professor William Benjamin, Professor Benny Freeman, Dr John Bradley, Dr Noel Brennan and Dr Douglas Vanderlaan.

Professor Valint is a research professor at the University of Buffalo and a consultant to the biomaterials industry. He joined the research division of B&L as a Research Fellow in 1988. From 1991 to 2001, he held the position of Senior Research Fellow and from 1992 to 1997, he was also appointed Surface Science Department Manager. During his tenure, he initiated B&L’s Surface Science Laboratory and Surface Science Core Technology Group to provide B&L with a significant research capability into new concepts of surface modification for biocompatibility and polymer surface characterisation. His duties included synthesis of new contact lens materials, development of novel surface modification techniques and characterisation of surface properties of lens materials. As part of his work, he routinely reviewed clinical information on contact lenses, including data on wettability, lipid and protein deposition, comfort, on-eye movement and wear time. He also routinely reviewed data relating to the physical properties of contact lenses and their surfaces, including oxygen permeability, water content and mechanical properties.

I found Professor Valint to be a thoroughly fair and knowledgeable witness. I wholly reject the suggestion made by the claimants that he occasionally lost his objectivity and began to argue the case for the defendants. However, it is plain that by the priority date B&L was one of the leaders in the search for an extended wear contact lens and had a level of knowledge that may not have been shared by the ordinary skilled person. This is a matter which I have had well in mind in assessing the issues which arise for determination in this case.

Professor Benjamin is a professor of optometry and a professor of vision science at the University of Alabama at Birmingham (“UAB”), School of Optometry. He joined the UAB School of Optometry in 1988 and throughout his career has been concerned with the clinical aspects of contact lens technology. He has developed a particular expertise in the measurement of oxygen permeability of contact lenses and was personally involved in the drafting of standards for the American National Standards Institute and the International Organization of Standards, including sections on the determination of oxygen permeability and transmissibility.

The claimants rather grudgingly accepted that Professor Benjamin is a highly competent scientist but contended that he too suffered from arguing the defendants’ case and on occasion lost his objectivity and strayed into the arena of advocacy. I reject these criticisms. Professor Benjamin was subjected to a vigorous cross examination but remained objective and courteous throughout. He was knowledgeable and focused and I have found his evidence of great assistance.

Professor Freeman is a professor of chemical engineering at the University of Texas at Austin. He has a distinguished academic record and is an expert in the solubility, diffusion and permeation of small molecules, including gases, liquids and ions, through polymers and in modelling and interpreting experimental data regarding small molecule permeability through single phase and multiphase polymers. He gave evidence about the ion permeability values reported in the Patent, and he explained and commented on experimental work concerning ion permeability and polymer morphology carried out in the course of this litigation.

I found Professor Freeman to be an outstanding witness. The opinions he expressed were objective, measured and cogent. He was not and did not profess to be in position to assist me as to the knowledge of the skilled person in the contact lens field at the date of the Patent, but he was well equipped to assist me in relation to issues of technical fact concerning the ion permeability of the materials in issue and the conclusions that could be drawn from experiments using an atomic force microscope (“AFM”) to investigate polymer morphology.

Dr Bradley is Director of the Institute of Geophysics & Planetary Physics, Lawrence Livermore National Laboratory, Livermore, California. He is an expert in the field of electron microscopy, including the preparation of samples and the evaluation of results in interpreting morphological structures. He gave evidence about the TEM, FEGSTEM and EDX experiments conducted for the purposes of this litigation.

Of all the defendants’ witnesses Dr Bradley was the subject of the most severe criticism. It was suggested that his evidence was not objective and that he had been hired by the defendants to advance a case that the morphology experiments were unreliable. Further, it was said he set about thinking of every conceivable point to take and upon which to argue the defendants’ case. In my judgment these criticisms are unwarranted. I formed the view that Dr Bradley is an extremely careful scientist who sets for himself and for others the very highest standards. He was subjected to a sustained and, at times, aggressive cross examination and I did not find it surprising he appeared somewhat defensive in response. Nevertheless, I think it right to note that Dr Bradley’s approach did make it more difficult to identify which of his criticisms were likely to have had a material effect on the outcome of the experiments and the conclusions which can properly be drawn from them and this is a matter to which I have had due regard in evaluating the evidence and reaching my conclusions.

Dr Brennan is Managing Director of Brennan Consultants Pty Ltd. He is an optometrist with extensive academic qualifications and practical experience and is an expert in the field of assessment of the clinical performance of contact lenses. Since 1982 he has undertaken research on extended wear contact lenses for government bodies and for major manufacturers including B&L, CooperVision, the claimants (or related companies) and the defendants. Dr Brennan gave evidence to explain the clinical studies of the prior art lenses undertaken for the purposes of this litigation.

I found Dr Brennan to be a fair, knowledgeable and careful witness and I reject the claimants suggestion that his approach to the interpretation of the data obtained was rather over optimistic. I have no doubt that the opinions he expressed were entirely genuine.

Dr Vanderlaan is a staff scientist employed by the defendants and was responsible for recreating the lenses described in Chang and Lai. He gave his evidence fairly and honestly. I will address the criticisms made of his approach to the art in considering the allegations of anticipation and obviousness but I reject the claimants’ suggestion that he attempted to conceal from the court the manner in which his protocol came to be devised. I found him to be entirely candid under cross examination.

A patent specification is addressed to those persons likely to have a practical interest in the subject matter of the invention, and such persons will have practical knowledge and experience of the kind of work in which the invention is intended to be used. They will also be equipped with the common general knowledge in the art, a topic to which I return below.

In the present case the parties were agreed that the person to whom the Patent is addressed is a team comprising first, a polymer chemist with at least five years’ experience in research and development of contact lenses and a degree in material science, polymer science or chemistry and, possibly, a PhD; second, a fully qualified optometrist or ophthalmologist with at least five years’ experience in the clinical evaluation of contact lens wear and users’ responses to contact lens wear; and third, an analytical chemist or materials scientist qualified to degree or PhD level and with practical experience of techniques used to measure standard chemical and physical properties such as oxygen permeability, water content and tensile modulus.

The common general knowledge is all the knowledge which is generally known and generally regarded as a good basis for further action by the bulk of those engaged in the field to which the invention relates: Beloit Technologies Inc v Valmet Paper Machinery Inc [1997] RPC 489 at pages 494-495.

In summarising the common general knowledge it is convenient to begin with a little history. Much of this was not in dispute and the following account is drawn largely from the evidence of Dr Port, Professor Koßmehl and Professor Valint.

In the early days contact lenses were made of glass but they had limited success as they were difficult to produce and uncomfortable to wear. In the 1940s a major advance was made with the discovery of the plastic poly(methyl methacrylate) (“PMMA”). This was found to be a suitable hard lens material in terms of its biocompatibility, mechanical and optical properties and relative ease of manufacture. However, PMMA lenses suffered from the drawback that they were still relatively uncomfortable and impermeable to liquids and gases.

In the 1970s a further important advance was made with the invention of polymers known as hydrogels. The first of note was called 2-hydroxyethyl methacrylate (“HEMA”), also known as polyHEMA. The rights to make lenses from this material were purchased by B&L, and in the early 1970s it introduced its polyHEMA “Soflens” contact lens.

Hydrogels are a rather unusual kind of polymer in that they are hydrophilic yet insoluble in water. When placed in water they swell to an extent which is related to the hydrophilicity of the monomers used in their production. Stability is introduced by the use of cross linking monomers such as poly (ethylene glycol) dimethacrylate to produce a three dimensional network. In addition to hydrophilic monomers and cross linkers, a hydrogel formulation may also contain other monomers such as methylmethacrylate (“MMA”) as a physical property modifier and solvent to facilitate processing.

A wide range of other hydrophilic monomers were also investigated. In particular, N-vinylpyrrolidone (“NVP”) and N,N-dimethyl acrylamide (“DMA”) proved useful, as did acid containing monomers such as methacrylic acid (“MAA”). The aim of those working in the field was to develop formulations with a high water content and so also high oxygen permeability. Polymerisation could be initiated using UV light and a photoinitiator.

Although hydrogel based lenses were initially all sold for daily wear, in the early 1980s the FDA approved the use of such lenses for extended periods of wear of up to 30 days. By 1987 it was estimated that they were being used in this way by around 4.1 million Americans. These extended wear lenses were primarily HEMA based and included copolymers with hydrophilic monomers such as DMA, NVP and MAA. Their oxygen permeability (sometimes referred to as “Dk” and measured in barrers or Dk units, and generally using the polarographic method) ranged from about 10 barrers for HEMA lenses to about 30 barrers for lenses made with HEMA and other hydrophilic monomers.

Unfortunately a number of those using these lenses for extended periods of wear began to show clinical complications. Most seriously it was found such users had a significantly greater risk of developing ulcerative keratitis, an extremely painful condition affecting the cornea. As a result, the FDA revised its approval and recommended a maximum extended wear time of seven days. Nevertheless hydrogel lenses, including a lens sold by the defendants under the name Acuvue, remained very popular.

In parallel with the development of hydrogel lenses, scientists were also looking to design lenses made from silicones, materials which combine the elements silicon, carbon and oxygen. One particular class of materials, those made of polydimethylsiloxane (“PDMS”), appeared to be ideal candidates for extended wear lenses because PDMS possesses excellent transparency and high oxygen permeability. However, due to the hydrophobic nature of silicone, these lenses were found to be essentially non wettable (and so required surface treatment) and their elastic nature made them susceptible to corneal adhesion. By 1995, B&L had one surface treated silicone elastomer lens on the market. It was called Silsoft and was used for extended wear in speciality cases only.

A further class of lenses under development at this time also justify a mention at this stage. Rigid gas permeable (“RGP”) lenses based on silicone (meth)acrylates were made by combining the stability and processing characteristics of MMA with the high oxygen permeability characteristics of silicone. In particular, it was found that copolymerization of MMA with the silicone 3-(methacryloxy)propyl tris(trimethysiloxyl)silane (“TRIS”) and wetting agents such as MAA allowed the production of a lens with good scratch resistance, wettability, dimensional stability and oxygen permeability. As a result, TRIS formed part of the general knowledge as being one of the standard building blocks for silicone containing contact lenses. But RGP lenses were not a success. Their rigid nature means they do not mould to the eye and so are not comfortable. In addition they have a tendency to bind to the cornea if worn overnight.

As a result of all this work, and indeed the further work in relation to silicone hydrogels which I consider later in this section, it was well understood that the design of any contact lens for extended wear must address a number of essential criteria.

The first is oxygen transmissibility. At the outset it is important to note that the oxygen transmissibility of a lens is a measure of the amount of oxygen that can pass through a particular lens and is calculated by dividing the oxygen permeability of the lens material by the lens thickness. Hence oxygen transmissibility (Dk/t) is a characteristic of a particular lens and is expressed in terms of barrers/mm where t is the average thickness of the material. Oxygen permeability, on the other hand, is a characteristic of the material from which the lens is made and does not depend on thickness. It is also expressed in terms of barrers or Dk units, but curiously a barrer in the case of permeability is defined as being an order of magnitude smaller than it is in the case of transmissibility. Hence a lens of a material having a permeability (Dk) of 100 barrers and a thickness of 0.1mm will have a transmissibility (Dk/t) of 100 barrers/mm.

Contact lenses rest on the cornea, a transparent body which transmits and refracts light into the eye. The cornea derives the oxygen it needs directly from the air. If it is deprived of oxygen it becomes hypoxic and begins to swell. In a seminal study published in 1984, Dr Brien Holden and Dr George Mertz investigated the relationship between corneal oedema (swelling) and the oxygen transmissibility of extended wear contact lenses. Holden and Mertz found that the oxygen transmissibility that limits overnight swelling to 4% (the level experienced by a non-contact lens wearer) is 87 barrers/mm. I am satisfied that as a result of this work and a number of similar studies it was a matter of common general knowledge by 1995 that an oxygen transmissibility of in excess of about 70 barrers/mm was necessary to avoid unnatural corneal swelling.

Unfortunately, this degree of oxygen transmissibility could not be achieved with hydrogel lenses. They derive their oxygen permeability from their water content and although it was known it was possible to increase the water content of polyHEMA, and hence also its oxygen permeability, by the incorporation of small amounts of MAA into the polymer, there was still a limit to how much water hydrogel lenses could absorb whilst maintaining their structural integrity and durability. As a consequence, the oxygen transmissibility of hydrogel lenses could not be increased beyond a certain point, commonly from 10 to 30 barrers/mm. Hydrogel lenses could therefore cause a high degree of hypoxia when used in extended wear applications. By contrast, silicone elastomers were known to be highly permeable to oxygen.

The second is movement on the eye. It was understood that in the healthy eye the cornea is covered by a continuous tear film which allows the exchange of ocular fluid, the provision of metabolic products to the cornea and the removal of metabolic by-products from the cornea. The ideal contact lens therefore allows the eye to maintain a tear film between the lens and the cornea, and this in turn was known to be affected by the degree to which the lens was free to move on the eye. One of the factors which was known to affect the ability of a lens to move on the eye was the hydrophilicity of the lens surface. The hydrogel lenses fulfilled this requirement admirably. But unfortunately the silicone elastomer lenses did not. They suffered both from adhesion of lipid deposits to the lens surface and adhesion of the lens to the cornea. As a result, silicone elastomer lenses were sometimes surface treated to make their surfaces more hydrophilic, but they were still prone to deposits of lipids and proteins on the lens surface and to adhesion to the cornea. It was also found that the surface treatments had a tendency to degrade fairly rapidly, giving poor vision and comfort.

The third is wettability. This is related to the lens characteristics which permit movement on the eye. The surfaces of the lens must be wettable so that a smooth, stable and continuous tear film is formed both behind and on front of the lens when it is worn, so ensuring corneal health, good vision and comfort. Again this was not a problem with the hydrogel lenses but it was a serious issue with silicone elastomer lenses, and one which was only partially addressed by the use of surface treatments.

In addition to these characteristics, a successful lens must also be optically transparent and biocompatible, possess chemical and thermal stability and have suitable mechanical properties, including (in the case of hydrogels) a low modulus of elasticity for patient comfort and a high tear strength for durability.

In the 1970s scientists began to combine silicone materials with hydrogels with the aim of obtaining the beneficial properties of both types of material. The theory was straightforward: such lenses would have the oxygen transmissibility characteristics of the silicones and the wettability and comfort of the hydrogels. One of the pioneers was Dr Karl Mueller of Ciba-Geigy who made a copolymer from a silicone containing macromer and the monomers HEMA, NVP and MMA which collectively introduced a hydrophilic quality. Others followed, including the inventors of Keogh, Chang and Lai. I have no doubt that by 1995 the general concept of making a silicone hydrogel lens from hydrophilic monomers such as DMA, NVP and HEMA and silicone monomers such as TRIS and PDMS was a matter of common general knowledge.

The production of a satisfactory extended wear lens did not, however, prove straightforward. One of the problems facing researchers was that the two different kinds of monomers are generally immiscible, and copolymerisation can result in opaque phase separated materials. This was addressed, at least to some extent, by the preparation of intermediate siloxane macromers containing hydrophilic groups. Several approaches were known, including synthesis of hydrophilic TRIS derivatives and of siloxanes containing hydrophilic end caps, blocks or side chains which aid their miscibility with the hydrophilic monomers and so assist in the formation of a clear polymer.

Another problem was achieving the right balance between wettability and oxygen permeability. It was appreciated that, in contrast to conventional hydrogels where the oxygen permeability is derived from the water content and so the two increase in proportion to each other, the opposite is true in the case of the silicone hydrogels. Here the presence of water decreases the oxygen permeability of the polymer composition. This relationship was well understood and is illustrated in this figure taken from an article published by Dr Jay Kunzler and Dr Joseph McGee (both of B&L) in August 1995:

Kunzler and McGee reported, as indeed is evident from the graph, that silicone hydrogels could be formulated to achieve a wide range of water content and oxygen permeability, with Dk values in the 50-200 barrer range. As is also apparent from the graph, lenses made of these materials could have a satisfactory oxygen permeability and a reasonably high water content of say 30%, which, as Professor Valint explained, was sufficient to get movement on the eye. However, an obstacle remained and that was how to achieve a surface chemistry which provided good biocompatibility and wetting characteristics. The hydrophobic surface characteristics of the lens, derived from its silicone content, made it difficult to maintain an adequate tear film, despite the lens itself having a reasonable, or even high, water content. This phenomenon was not well understood in 1995 but appeared to arise from the tendency of hydrophilic siloxane groups to dominate the surface chemistry of any resultant lens. Considerable research was therefore undertaken by workers in the field to find a polymer structure which would produce a single clear material from which to make a homogenous, clear lens whilst incorporating the oxygen permeability of silicone elastomers, but retaining the biocompatibility and wettability of conventional hydrogels.

The issue of wettability was therefore fundamental to the development of an extended wear lens. The evidence established that the skilled person would have been aware of the possibility of surface treatment, using techniques such as plasma coating and plasma oxidation, to improve the wettability of a silicone hydrogel lens. Professor Valint considered this was the case, it was something to which B&L resorted and, as will be seen, it was described by Chang. Similarly, Dr Port agreed that plasma treatment in general, including those plasma treatments carried out by a Dr Yasuda and published in 1985, were well known to the person skilled in the art by 1995. Professor Koßmehl also accepted that the concept of surface treatment was well known.

The effectiveness of surface treatment in the context of silicone hydrogels had not, however, been established. Professor Valint agreed that the ordinary skilled person would not have had experience of the successful modification of lens surfaces to make an extended wear lens. Professor Koßmehl explained that the skilled person would have considered that the then known surface treatments for silicone elastomers were short lived. Indeed the Kirk-Othmer encyclopaedia, published in 1995 and which was accepted to contain the common general knowledge, recited that although surface treatments, both physical and chemical, had demonstrated the ability to alter the specific properties of contact lens surfaces, most treatments “fail as a result of alteration of bulk lens properties, instability of surface treatment, or poor ocular compatibility.” Moreover, it continued, “Research is expected to continue in the characterization and modification of contact lens surfaces”.

Overall, Professor Valint agreed with Professor Koßmehl’s opinion that in 1995 the area of silicone hydrogels was still experimental. Research had been going on for 20 years and many different materials had been proposed, but none had been proven. There were no commercially available silicone hydrogel lenses and significant challenges remained.

By 1995 there were two principal ways of making soft contact lenses, namely lathing and cast moulding. In the case of the former, rods of polymer are formed and these are then cut into buttons and lathed to form lenses. In the case of the latter, the liquid mixture of silicone monomers and macromers and hydrophilic monomers is placed into a mould and cured, typically with UV radiation. The mould is then opened and the lens extracted, washed and treated as necessary. I am satisfied that the skilled person would have been well aware of both techniques in 1995. The evidence also established that the manufacturing method may affect the chemical and morphological structure of a lens and the topography of the finished lens material. I refer to some other more detailed aspects of the common general knowledge relating to polymer composition and manufacturing techniques later in this judgment in addressing the particular attacks on the Patent.

The Patent describes the field of the invention as relating to polymeric material and treatment processes useful in the manufacture of contact lenses and, more specifically, extended wear contact lenses.

It summarises the state of the art in a section headed “Description of the Related Art.” I have addressed much of this in considering the common general knowledge. But certain points merit emphasis. Ophthalmic compatibility is said to involve the dual requirements that the lens allows sufficient oxygen to reach the cornea to maintain corneal health and that the lens does not adhere strongly to the eye and, indeed, can move on the eye. RGP lenses are recognised to meet both requirements but are typically quite uncomfortable, so excluding them as effective extended wear candidates. It then describes the poly(HEMA) lenses which both move well on the eye and provide sufficient oxygen permeability for daily wear but explains that they cannot be worn for “true” extended wear, that is to say seven days or more, because their oxygen permeability is insufficient and so they result in corneal swelling. By contrast, polysiloxanes have high oxygen permeability but adhere to the eye and their lipophilicity promotes adhesion of lipids and proteins causing a haze which interferes with vision. The specification concludes that attempts to blend the desirable properties of hydrophilic polymers and polysiloxanes have failed, either because of the effect of the extended wear lens on corneal health or because the lens would not move on the eye.

Against this background the Patent describes the “Objects and Summary of the Invention”. Paragraph [0009] explains that it is an object of the invention to provide an ophthalmic lens having a balance of oxygen permeability, ion permeability, on-eye movement and tear exchange, all of which are sufficient for corneal health and wearer comfort during extended periods of continuous wear. This is a disclosure of some significance. It is, say the claimants, the first time anyone had taught the importance of a combination of high ion permeability and a high oxygen permeability to achieve a successful extended wear lens. Whilst the desirability of high oxygen permeability was known, the desirability of high ion permeability was not known – and the Patent teaches for the first time that ion permeability is an important predictor of on-eye movement.

A further object is described in paragraph [0010] as being to provide an ophthalmic lens capable of extended continuous wear of at least 24 hours without substantial adverse impact on ocular health or consumer comfort. This is an important paragraph in that it describes “extended wear” by reference to a minimum of 24 hours of continuous wear.

The “Description of the Preferred Embodiments” is divided into six sections of which the first, section I, is a “Definition of Terms”. It is convenient at this point to refer to some of these definitions; others I will address in context.

Paragraph [0019] defines “oxyperm polymers” as those which allow a relatively high rate of oxygen diffusion through them. Later, at paragraph [0038], the Patent explains that preferred oxyperm polymers are made from a siloxane containing macromer, particularly PDMS. As Professor Koßmehl accepted, oxyperm materials were known, including many of the specific examples taught in the Patent. Others are novel, and in particular the oxyperm macromers of the A, B, C and D families of materials described later in the specification.

“Oxygen transmissibility” and “oxygen permeability” are defined in paragraphs [0020] and [0021] as having their conventional meanings which I have explained.

“Ionoperm polymers” are defined in paragraph [0023] as polymers which allow a relatively high rate of ion or water permeability through them. Paragraph [0041] gives a number of examples of ionoperm polymerizable materials. Some, such as HEMA, DMA and NVP were well known as hydrophilic contact lens materials. But once again, others were novel.

The definition of ophthalmic compatibility appears in paragraph [0030] in these terms:

The Patent then turns in section II to address the topic of “Core Polymer and Lens” and, as I have mentioned, from paragraphs [0037] to [0041] explains the nature of the oxyperm and ionoperm polymerizable materials contemplated by the invention. As for the oxyperm materials, it is said that the oxygen transmissibility of the lens should preferably be at least 70 barrers/mm and most preferably at least 87 barrers/mm, figures that were known to be desirable from the common general knowledge.

Paragraph [0042] teaches that the ratios of oxyperm to ionoperm polymerizable materials may vary substantially. Preferably, the volumetric ratio of oxyperm to ionoperm material (including water) in the fully hydrated lens is about 40 to about 60 to about 60 to about 40. In terms of weight percentages, it is said that preferably the extended wear lenses having substantially only ionoperm and oxyperm materials will have about 60 to about 85 weight percent oxyperm polymerizable material and about 15 to about 40 weight percent ionoperm polymerizable material in the prepolymerization mixture, based on total polymerizable material weight.

Paragraph [0043] explains that a wide variety of additional polymerizable materials may be included in the mixture prior to polymerization. For example, cross-linking agents may provide structural integrity and mechanical strength, antimicrobial materials may inhibit microbial growth on the lens material and additional ionoperm or oxyperm monomers may be added to adjust the oxygen permeability and the ion permeability of the final moulded article. An especially advantageous material is said to be TRIS, a component with which the skilled person would have been familiar.

Paragraphs [0044] to [0046] contain further detail about the mixture and, importantly, a teaching that the specific weight or volume percentages of oxyperm and ionoperm polymerizable materials are not the most critical factors to consider in preparing a good extended wear lens. More importantly, the lens must have sufficient ion permeability for good on-eye movement and sufficient oxygen permeability for good corneal health during the extended wear period.

Paragraphs [0047]-[0049] contain some interesting teaching about morphology. In these paragraphs and, it is said, contrary to the conventional wisdom, the Patent explains that in a preferred embodiment the lens material has at least two phases, including at least one oxyperm phase and one ionoperm phase, with the further possibility of a transition phase which consists of a blend of the oxyperm and ionoperm materials. In a particularly preferred embodiment, the lens has two co-continuous phases, one an oxyperm phase and the other an ionoperm phase, allowing for permeation of water or ions and oxygen between the front and base curves of the lens. As will be seen, this forms the basis for claims 8 and 11.

Paragraphs [0052] to [0053] contain teaching as to the appropriate bulk water content. A lens with a water content of about 10 to 30 weight per cent is preferred.

Paragraphs [0054] to [0060] provide a detailed exposition of ion and water permeability. The claimants attach particular importance to the following:

In summary, these paragraphs explain that ion permeability is directly proportional to water permeability and that it correlates well with and is a predictor of on-eye movement. It is said that above a certain threshold of ion permeability through a lens, it will move on the eye, and below the threshold it will adhere to the eye. It is also suggested the permeability is achieved by providing what are described as ion transmission pathways for ion and water movement through the lens.

There follows a description of two techniques for measuring ion permeability, namely the “Ionoflux” and “Ionoton” measurement techniques which produce values for ion permeability referred to as the Ionoflux Diffusion Coefficient and the Ionoton Ion Permeability Coefficient respectively.

Water permeability may be measured by a technique called the “Hydrodell Technique” which is explained in paragraphs [0073] to [0091]. It did not receive much attention during the trial, I assume because the Patent says that it is believed that water permeability is directly proportional to ion permeability.

Measurement of oxygen transmissibility and permeability is described in paragraphs [0092] to [0095]. At this stage I need only observe that the Patent explains that the permeability and transmissibility of a lens may be determined by assessing the oxygen flux through the lens using a Dk1000 instrument. Later, in paragraph [0334], the Patent teaches that the oxygen permeability is determined using the coulometric method, which raises an issue to which I must return in addressing the prior art.

This is followed by a description of the assessment of various mechanical parameters such as tensile modulus, relaxation time and tan delta – a factor measured by dynamic mechanical analysis.

The Patent then sets out in considerable detail from paragraphs [0107] to [0278] a description of the four families of materials A, B, C and D which are said to be suitable core materials of the ophthalmic lenses of the invention.

Section III of the description of the preferred embodiments addresses the issue of ophthalmically compatible surfaces. Paragraphs [0279] to [0284] explain, as was known, that the surface of the lens must be biocompatible with ocular tissue and ocular fluids during the desired extended period of contact. In a preferred embodiment the surface is more hydrophilic and lipophobic than the core. This may be achieved by the use of various surface treatments described in the art, including, in the case of some specific examples, those described by Yasuda, which, as I have said, were accepted by Dr Port to be matters of common general knowledge.

Section IV is concerned with utility and explains that the materials described in the specification may be used for a wide variety of different kinds of lenses in addition to those for vision correction, and including lenses for cosmetic purposes, drug delivery, wound healing and the like.

Paragraph [0287] explains that the necessary balance of properties, including especially high ion permeability in combination with high oxygen permeability is key to producing a true extended wear contact lens. The high oxygen permeability is required to prevent corneal swelling, thereby reducing the risk of ocular damage and wearer discomfort, and the high ion permeability enables the lens to move on the eye such that corneal health is not substantially altered and wearer comfort is maintained over a period of extended wear. But what, say the defendants, is noticeably missing is any exposition as to how that balance is to be achieved.

Section V is a short section addressing “Method of Use as Extended-Wear Lenses” and this is followed in section VI with a long description of “Methods of Manufacture”.

This section begins with a description of the general process of manufacture. It explains that lenses may generally be made by thoroughly mixing the oxyperm and ionoperm materials, applying an appropriate amount of the mixture to the lens mould cavity and initiating polymerisation, preferably by photoinitiation using UV light. The Patent also teaches that ion permeability of some of the materials may be increased by carrying out the polymerisation in an atmosphere which is substantially free of oxygen. The importance of degassing the prepolymer mixture prior to polymerisation in order to promote ion permeability and on-eye movement is also taught; as is an alternative method which permits the atmosphere around the mould to include oxygen provided that certain conditions are met so as to exclude the oxygen from the prepolymer mixture before and during polymerisation.

The Patent then proceeds to describe a large number of examples. It begins with a detailed description of the preparation of the polymers in each of the families A to D and the production of lenses from those materials. They vary quite considerably. The A examples teach the preparation of macromers having both ionoperm and oxyperm segments built into the macromer and then the use of the macromers in preparing lenses either alone or with other ionoperm and oxyperm polymerizable materials and a cross linker.

The B examples involve the use of another class of macromer including two different oxyperm segments, one of PDMS and one of a perfluoropolyether. These are then used to make lenses with other polymerizable materials, including ionoperm materials.

The C examples teach the use of a yet further macromer class, this time based on a polysiloxane oxyperm segment having one or more polyol groups attached to it.

The D examples are based on a fourth kind of macromer, namely a PDMS material with polymerizable end groups which may then be combined with additional ionoperm and oxyperm polymerizable materials to make lenses.

Examples E are described from paragraph [0381] to [0396] of the Patent. 13 lenses were produced and tested (examples E-1 to E-13) and the Patent then draws certain conclusions. The lenses were made of a variety of materials from families A, B, C and D. All were subjected to some kind of degassing procedure, some were cured in nitrogen and some were surface treated. They were all then tested to determine their Ionoton Ion Permeability Coefficient and for on-eye movement. The results are presented in table E. Certain, albeit rather limited conclusions can be drawn. For example, examples E-10 and E-13 are the same, save that E-13 was cured in air. Curing in air resulted in a drop in the Ionoton Ion Permeability Coefficient and the lens did not move on the eye. Examples E-3, E-4 and E-5 were all made of material B-12 but were subjected to either no or different degrees of plasma surface treatment. It can be seen that the greater the plasma treatment, the lower the Ionoton Ion Permeability Coefficient, but all moved on the eye. The same conclusion emerges from a comparison of E-7 and E-8, both of which were made from material C-21. Beyond this, it is not easy to draw conclusions because a number of variables change between the examples so it is difficult to attribute on-eye movement to any particular one of them.

Nevertheless, and subject to the above, the Patent explains in paragraph [0396] that if Ionoton permeability alone is considered, the lowest value at which a lens moved on the eye is 0.25 x 10^-3 cm²/sec (i.e. 250 x 10^-6 cm²/sec) and the highest value at which a lens bound to the eye is 0.008 x 10^-3 cm²/sec (i.e. 8 x 10^-6 cm²/sec). Thus, it says, a contact lens preferably has an Ionoton Ion Permeability Coefficient greater than 0.008 x 10^-3 cm²/sec and more preferably greater than about 0.25 x 10^-3 cm²/sec.

Examples F are described from paragraphs [0397] to [0414] of the Patent. Another 12 lenses (examples F-1 to F-12) were made and tested. These were made from a variety of materials from classes B and C. In this case the lenses were apparently moulded, then tested for their Ionoflux Ion Permeability Coefficient and thereafter surface treated with polyvinylpyrrolidone (“PVP”) before being tested for on-eye movement. Professor Valint considered, and I agree, that this seemed a rather curious way to carry out the examples because, as has been seen, it cannot be assumed that the ion permeability of an uncoated lens is the same as that of a coated lens. Nevertheless, table F records the results of the Ionoflux measurements and whether or not the lenses moved on the eye.

Paragraph [0414] draws the conclusion from the table that the lowest value of Ionoflux Ion Permeability Coefficient for which a lens moved on the eye was 2.6 x 10^-6 mm²/min; and the highest value of Ionoflux Ion Permeability Coefficient for which a lens bound to the eye was 1.5 x 10^-6 mm²/min, but, as I say, these measurements were taken before surface treatment.

Finally, examples G are addressed from paragraphs [0415] to [0422]. Here six lenses (examples G-1 to G-7) were made from various materials drawn from classes A, B, C and D. They all have different chemistry. Some were surface treated with PVP and some were not. Then, in respect of each lens, its water permeability was determined and its ability to move on the eye assessed. Only one lens did not move on the eye and it was the only one which was not surface treated.

Professor Koßmehl suggested that analysis of the various water contents of the various lenses the subject of the examples showed no correlation between water content and on-eye movement, nor between water content and water permeability. In the light of the evidence of Professor Valint, I believe there are simply too many variables between the relevant lenses to be able to draw a conclusion one way or the other on these issues from the data in the Patent. However, this is not the end of the matter, as I shall explain in considering the validity attack.

The Patent has a very large number of claims, many of which were asserted to have independent validity depending upon the particular attack made. At this stage it is sufficient to focus only on the primary claims asserted to be infringed and independently inventive, namely claims 1, 8, 11 and 24.

It is convenient to begin with claim 1, which was helpfully broken down by the claimants into the following integers:

Some general observations may be made about this claim at the outset. It is a product claim, and hence it encompasses all lenses which satisfy its various integers, irrespective of how they have been made. More specifically, it is not limited to lenses made of materials which have been identified using ion permeability as a way of filtering out those materials which are suitable from those which are not. Indeed, Dr Port was not aware of any material other than that used in the claimants’ FND product which has been discovered by measuring the ion permeability of a number of samples, and he accepted that ion permeability has not become the touchstone by which suitable silicone hydrogels are identified. Further, it is a claim which has certain quantitative limitations which require measurements to be taken and certain “soft” functional criteria, which require a clinical assessment to be made. Finally, as follows from the foregoing, it is a claim which is limited by function in that it only encompasses lenses which are ophthalmically compatible during a period of extended wear. In short, it only covers lenses which “work”. I must now consider the integers in issue.

I have set out the definition of ophthalmic compatibility provided in the Patent in paragraph [67] of this judgment. It is to be noted that it is cast in general terms. So, for example, the lens must be suitable for extended wear without “significantly damaging” the ocular environment and without “significant user discomfort”. It must be such that it will not produce “significant corneal swelling”, that it will “adequately move on the eye” and promote “adequate tear exchange”, that it will not have “substantial amounts of lipid adsorption” and will not cause “substantial wearer discomfort”. How are these functional criteria to be assessed? The difficulty of interpretation they present was described by Dr Brennan. He explained, and I accept, that there is no generally accepted threshold of ophthalmic compatibility, that different wearers can have different responses and that even the claimants’ FND commercial product can cause damage to the eye. As for corneal swelling, paragraph [0040] of the Patent contemplates corneal swelling of less than about 8% using preferred extended wear contact lenses and claim 47 limits the degree of permissible swelling to less than about 8%, suggesting that a greater degree of swelling may be acceptable in the case of claim 1. Moreover, there is no description in the Patent of any clinical testing at all.

In these circumstances the defendants contend that the functional requirements are met (and only met) by a product which is of a quality that could be submitted for regulatory approval if the devisor thought fit to do so. In my judgment this sets the threshold far too high. A lens which seems promising might ultimately fail for reasons quite unconnected with any of the problems addressed by the Patent. I believe the Patent is directed to a team interested in making workable prototypes of lenses which can then be carried forward into more extensive clinical trials. Such a team would carry out small scale clinical assessments, using a minimum of from 6 to 10 patients but reasonably up to about 30, and look to mean and median responses for the group, just as the defendants did in seeking to reproduce the prior art.

Extended wear is a minimum period of 24 hours of continuous wear, as explained in paragraph [0010] of the Patent. In practice such a lens would be of little commercial interest, with those in the art seeking to make lenses which could be used for extended periods of wear of up to 30 days and so satisfy the demand previously met by the early hydrogel lenses. In this regard it is to be noted that subsidiary claims 51 to 54 limit claim 1 to periods of extended continuous wear of 4, 7, 14 and 30 days respectively.

In the course of the trial the claimants accepted these words add nothing to the other limitations in the claim and, in particular, the requirements of ophthalmic compatibility and the quantitative criteria of integers (I) and (J).

As I have mentioned, oxygen transmissibility is defined in paragraph [0020] of the Patent in a conventional way and one which does not require it to be measured or determined using any particular equipment or method. Later, the Patent explains that it may be determined using a Dk1000 instrument and, in the examples, that oxygen permeability is determined using the wet coulometric method. However, I do not believe the skilled person would understand either of these to be limitations in the claim. He would be aware from his general knowledge that he has a number of techniques at his disposal and that they should all give the same absolute value, if used properly. Nevertheless he would understand that the Dk1000 is an appropriate instrument to use and the wet coulometric method a reasonable one to adopt.

In contrast to oxygen permeability, the claim does specify that ion permeability must be measured by one of two particular techniques so as to derive an Ionoton Ion Permeability Coefficient or an Ionoflux Diffusion Coefficient. There is no dispute that although the data in table F is labelled Ionoflux Ion Permeability Coefficient, this is the same Ionoflux parameter as that referred to in the claim. More importantly, it is to be noted that a lens falls in the claim if either threshold is exceeded.

The units of each of these parameters are the same, save that Ionoton uses cm²/sec and Ionoflux uses mm²/min. Hence a multiplicand of 6000 is needed to convert one to the other. The Ionoton limitation is 0.2 x 10^-6 cm²/sec, or 2 x 10^-7 cm²/sec. The Ionoflux limitation is 1.5 x 10^-6 mm²/min, or 2.5 x 10^-10 cm²/sec. As the defendants point out, this is a difference of three orders of magnitude and it forms one of the arguments in support of the allegation of insufficiency. They say that, as in the case of oxygen permeability, they are both measuring the same absolute value and so should be about the same. Moreover, the Ionoton limitation is impossibly high and the Ionoflux limitation is very low and easily, if not inevitably, satisfied, with the result that the test is of no practical benefit. This, they continue, is very relevant to the allegation of insufficiency. These matters are hotly disputed by the claimants and I must consider them in detail later in this judgment.

Claim 8 reads:

This raises only one issue of interpretation as to the meaning of the term “phase”. The defendants contend that it presents difficulties because the specification gives no adequate guidance as to the size of the respective phases or how they should be measured, nor does it give guidance as to how the skilled person is to determine whether a phase or pathway extends continuously from the inner surface of the lens to the outer surface.

In my judgment these submissions go too far. The terms “phase”, “continuous phase” and co-continuous phases” are defined in paragraphs [0026], [0027] and [0028] of the Patent respectively. A phase must be of substantially uniform composition but need not be chemically pure. More specifically, an ionoperm phase must be composed of essentially only ionoperm polymer and an oxyperm phase must be composed of essentially only oxyperm polymer. A continuous phase must be of substantially uniform composition and form a continuous pathway from one surface of the lens to another, and co-continuous phases must have at least two such pathways. The Patent also teaches at paragraph [0173] that phase separation is in the region of less that 300nm, and so less than the wavelength of light, so as to avoid image distortion and reduction in light transmission. I recognise, however, that the specification gives no guidance as to the particular techniques to be used for determining the existence of such phases and pathways and so the skilled person would have to turn to his common general knowledge. This is another matter to which I must return.

Claim 11 reads:

This claim presents no additional issues of interpretation and the claimants accept that so far as obviousness is concerned it stands or falls together with claim 8.

Claim 24 reads:

Again this claim presents no additional issues of interpretation. It was common ground that the skilled person would have known of the sessile drop contact angle test to assess relative hydrophilicity and the results obtained using this test give rise to another of the issues on infringement.

The attack of lack of novelty over Hopken and Domschke is made under section 2(3) of the Act and, as I have outlined, requires a consideration of two issues: first, whether the Patent is entitled to its claimed priority dates and second, if it is not, whether Hopken and Domschke provide an enabling disclosure of lenses falling within the scope of the claims. I will consider them in turn.

The Patent claims priority from three earlier applications:

European patent application 95810221 of 4 April 1995 (the first priority document);

Swiss patent application 1496/95 of 19 May 1995 (the second priority document);

US patent application 569816 of 8 December 1995 (the third priority document).

The first and second priority documents disclose lenses made of materials B and C respectively but they contain no disclosure of the claimed methods of measuring ion permeability, nor do they say whether the lenses are ophthalmically compatible over a period of extended wear. In these circumstances the defendants say that the priority documents can afford priority to a claim to contact lenses made of materials B and C but they cannot support or give priority to a claim either to:

a subset of contact lenses made of materials B and C defined by the additional criteria of ion permeability or ophthalmic compatibility;

a claim to contact lenses other than those made of materials B and C.

The claimants respond that the claims of the Patent may contain multiple inventions which are entitled to different priority dates. In so far as any lens or class of lens disclosed in a priority document falls in the scope of any claim of the Patent then the inventions of the claim are, to that extent, supported by the disclosure of the priority document and entitled to the same priority. Moreover, it matters not that ion permeability and ophthalmic compatibility are not expressly described because they are necessarily inherent features of any lens or class of lens which falls in the scope of any such claim.

Under Article 87(1) EPC, a European patent application is entitled to a priority date earlier than the date of filing if “the same invention” has been disclosed in an earlier relevant application. The meaning of the expression “the same invention” was considered by the Enlarged Board of Appeal of the EPO in G02/98 [2001] OJ EPO 413; [2002] EPOR 167. It concluded:

More recently the Court of Appeal has explained how this test is to be applied in Pharmacia Corp v Merck & Co Inc [2002] RPC 41 and Unilin Beheer NV v Berry Floor NV [2005] FSR 6. The priority document must contain sufficient material for the priority document to constitute an enabling disclosure of the claim concerned. Further, the priority document must give the skilled person essentially the same information as forms the subject of the later claim. In short, the priority document must implicitly or explicitly disclose and enable the claimed invention.

In most cases, these principles will be enough to address any priority question. But the present case raises the additional complexity of partial and multiple priorities. These are specifically contemplated by Article 88 EPC which reads, so far as relevant:

It follows that different claims may have different priority dates and, in an appropriate case, multiple priorities may even be claimed for one claim.

In decision G02/98 the Enlarged Board explored the legislative intent behind Article 88 and provided this guidance as to its proper interpretation:

I discern from this passage that the EPO considers it is permissible to afford different priority dates to different parts of a patent claim where those parts represent a limited number of clearly defined alternative subject-matters and those alternative subject-matters have been disclosed (and are enabled) by different priority documents. Further, this principle applies even if the claim has adopted a generic term to describe and encompass those alternatives. I do not detect anything in the decisions of the Court of Appeal in Pharmacia and Unilin Beheer which is inconsistent with this approach and in my judgment it is one which this court should adopt.

In the present case I must therefore consider whether, as the claimants contend, the claims can be divided into a limited number of clearly defined alternative subject-matters, some of which comprise the lenses described and disclosed in the first and second priority documents.

The following points are, I think, relevant. First, it is a key limiting feature of the invention of claim 1 that the claimed lenses have an ion permeability value above one of two defined thresholds and a further key limiting feature that the lenses are ophthalmically compatible and suited for extended wear. Second, these features are related in that the Patent explains at paragraphs [0054] to [0060] that ion permeability correlates well with and is a predictor of on-eye movement, that above a certain threshold of ion permeability the lens will move on the eye and that below the threshold the lens will adhere to the eye. In other words, the skilled person is taught by the Patent to use the disclosed ion permeability thresholds as a way to identify lenses which may be ophthalmically compatible. Third, it cannot be said that all the lenses made of materials B and C will inevitably have ion permeability values above the claimed thresholds. Such is apparent from table E where it can be seen that example E-2 (which was made of material B-10) had a negative Ionoton Ion Permeability Coefficient and did not move on the eye. Accordingly an ion permeability value above the claimed thresholds is not an inherent characteristic of all such materials or lenses made from them. To the contrary, the Patent teaches the skilled person to select only certain materials from all those disclosed in classes B and C and to do so on the basis of a parameter which was not disclosed in the first and second priority documents.

In these circumstances can the claims be divided into a limited number of clearly defined alternative subject-matters, some of which are disclosed and enabled by the first and second priority documents? I think the answer to this question is clearly no. The subject matter of claim 1 is a class of lenses tied together by a number of unifying features, including specifically that they have an ion permeability above certain defined thresholds and are ophthalmically compatible over a period of extended wear. These features cannot be ignored; nor can they be considered separately from each other. They are essential features of the invention and they are not disclosed in either of the first and second priority documents. It follows that the claims are not entitled to priority.

The test that must be applied in considering an allegation of anticipation was explained by the House of Lords in Synthon v SmithKline Beecham [2005] UKHL 59; [2006] RPC 10. It has two requirements, prior disclosure and enablement. To satisfy the prior disclosure requirement it must be shown that the prior art contains a clear description of, or clear instructions to make, something that would necessarily infringe the patentee’s claim if carried out after the grant of the patentee’s patent. I discuss the requirement of enablement later in this judgment in considering whether the Patent itself discloses the invention in a manner sufficiently clearly and completely enough for it to be performed by a person skilled in the art.

The defendants contend that although Hopken and the first priority document do not clearly and unambiguously disclose the features of claim 1, they do disclose the use of material B to make a lens. Accordingly, if and in so far as the specification of the Patent teaches sufficiently how to make a lens using material B, then so does Hopken.

Much the same applies to Domschke and the second priority document. The defendants say it discloses the use of material C to make a lens. Again, if and in so far as the specification of the Patent teaches sufficiently how to make a lens using material C, then so does Domschke.

So far as Hopken is concerned, the defendants say:

Lenses B-1 to B-13, disclosed on pages 26 to 31 of Hopken destroy the novelty of claims 1 to 24, 29 to 36, 39 and 40, 46 to 65 of the Patent.

There is a disclosure of a class of lenses made from a macromer of formula (I) on page 2 of Hopken. Hopken therefore discloses a class of lenses which is the same as, or substantially overlaps with, the class of lenses identified in claims 39 and 40 of the Patent (which is in turn a subset of claim 1 of the Patent).

The product of claim 54 of Hopken is materially the same as claims 39 and 40 of the Patent.

The text of Hopken from pages 2 to 14 corresponds to, and is materially the same as, page 17 line 39 to page 22 line 52 of the Patent.

The paragraph bridging page 16 to 17 of Hopken which includes the reference to such contact lenses having “excellent compatibility with the human cornea and with tear fluid” and being of “high comfort”.

In addition to the example lenses referred to above, examples A-1 to A-4 (pages 24 to 28) in Hopken correspond to examples B-1 to B-4 in the Patent, which are used in the production of the lenses.

Examples B1 to B4 of Hopken are the same as examples B-5 to B-8 of the Patent. Examples B-12 and B-13 of Hopken are the same as examples B9 and B10 of the Patent. Example B5 is the basis for FND, the lens which is said to be the commercial manifestation of the Patent.

The information contained in table B-I on page 42 of the Patent which is also contained in the table on page 31 of Hopken.

So far as Domschke is concerned, the defendants say:

Lenses B-1 to B-32 are disclosed on pages 37 to 42 of Domschke which serve to destroy the novelty of claims 1 to 24, 29 to 36, 41, 42 and 46 to 65 of the Patent.

There is a disclosure of a class of lenses made from a macromer of formula (I) (page 2). Domschke therefore discloses a class of lenses which is the same as, or substantially overlaps with, the class of lenses identified in claims 41 and 42 of the Patent which is in turn a subset of claim 1 of the Patent.

The product of claim 70 of Domschke is materially the same as claims 41 and 42 of the Patent.

The text of Domschke from page 1 to page 23 (end of first paragraph) and page 24 (last paragraph) to page 25 (third paragraph) corresponds to, and is materially the same as, pages 22 line 55 to page 33 line 1 of the Patent.

The paragraph bridging pages 25 to 26 of Domschke discloses that the contact lenses of Domschke have “excellent tolerability by the human cornea” and are of “high comfort” and are “specifically suitable for wear over a relatively long period of time (extended wear)”.

Examples A-1 to A-13 in Domschke correspond to examples C-1 to C-13 in the Patent, which are used in the production of the lenses.

Examples B-1 of Domschke is the same as example C-14 of the Patent; examples B-6 to B-10 of Domschke are the same as examples C-15 to C-19 of the Patent; and examples B-13, B-29 and B-30 of Domschke are the same as examples C-22, C-23 and C-24 of the Patent respectively.

The Dk [barrer] and E modulus [MPa] values contained in table C-II on page 46 of the Patent are contained in the table on page 39 of Domschke.

The defendants’ case may be illustrated by reference to example B-5. They say that material B is disclosed in Hopken as being suitable for producing lenses falling in the scope of claim 1 and that example B-5 is disclosed as having the parameters of claim 1. If the Patent is enabling then anybody using example B-5 to make a lens would inevitably make a lens falling in the claim. It follows that anyone using Hopken would do so also.

The claimants do not accept these contentions, as first became apparent when the defendants launched an application for summary judgment in 2008. At a hearing for directions on 8 September 2008 the claimants argued that lenses made of materials B and C may not have the features of claim 1. The following interchange took place, as recorded on page 52 of the transcript:

And a little later:

On 6 October, 27 October and 10 November 2008 the claimants filed a series of statements of case elaborating their position. In summary, and save where it is apparent from the results provided in the Patent that a particular example or class of lens does not satisfy the requirements of any claim, the claimants do not advance a positive case one way or the other but instead put in issue whether the examples and classes of lenses upon which the defendants rely satisfy the integers of the claims, including whether they have ophthalmically compatible inner and outer surfaces, are suited to extended periods of wear, allow sufficient oxygen permeation to maintain corneal health and wearer comfort and have an ion permeability above the specified threshold levels. In short, the claimants say that it is simply not possible to tell whether any particular lens or class of lens does or does not satisfy the requirements of the claims unless and until it is tested.

By the end of the trial I understood the defendants to have adopted the same position. Their primary case is that I do not have sufficient evidence to enable me to come to a conclusion as to whether the examples and classes of lenses described in Hopken and Domschke do or do not satisfy the requirements of the claims. It follows, they say, that I do not have a basis for concluding that example B-5 of the Patent satisfies the requirements of claim 1.

I must return to the consequences of the parties’ submissions in considering the allegation of insufficiency later in this judgment and for the moment confine myself to the attack of lack of novelty over Hopken and Domschke. In the light of the common position taken by the parties and the evidence on the subject, I do not feel able to conclude that the examples and classes of lens relied upon satisfy all the requirements of any of the claims. It has not been shown that the prior disclosure requirement is satisfied. The allegation of lack of novelty based on Hopken and Domschke therefore fails.

This is a conventional allegation of obviousness over the common general knowledge which was explained by Professor Valint in his first report. It runs as follows. By 1995, it was well understood that silicone hydrogels had the potential to combine the oxygen transmissibility characteristics of the silicones and the wettability and comfort of the hydrogels. Further, it was known that an oxygen transmissibility of an excess of 70 barrers/mm was necessary to avoid unnatural corneal swelling. The skilled person would have known of the need to balance water content against oxygen permeability, appreciating that lenses with high water contents showed movement on the eye and were comfortable. Further, in so far as such a lens suffered from poor wettability then it was obvious to apply the common general knowledge surface treatment procedures. A lens made in such a way would have satisfied all the requirements of claim 1 of the Patent.

Attractively simple though it is, this attack on the Patent did not survive cross examination. As Professor Valint explained, those working in the field had no difficulty in making a silicone hydrogel lens with a relatively high oxygen permeability. The problem they faced was producing a satisfactory wettable lens. It was the combination of high oxygen permeability and wettability that had proved elusive. Indeed, researchers had been trying for 20 years without success to produce a silicone hydrogel lens that was suitable for extended wear.

B&L was no exception. In Professor Valint’s words, they struggled with their silicone hydrogel formulations to make an extended wear lens. They too faced the problem of achieving satisfactory wettability of the lens surface, arising, so they thought, from a tendency of the silicone content to present itself at the lens surface. Their answer was finally to give in to the need to carry out a surface treatment process. They chose to carry forward their particular polymeric material known as RD-677 and surface treated it using the Silsoft plasma oxidation technique they were already using. This was part of what Professor Valint described as a programme including “lines of research” and “a lot of invention of new materials”.

I am satisfied it was not obvious how to make a silicone hydrogel lens which was ophthalmically compatible over a period of extended wear in the light of the common general knowledge at the priority date.

The defendants’ primary case is that each of these publications deprives the Patent of novelty. Their secondary case is that they render the Patent invalid for obviousness.

In relation to Chang and Lai, the defendants rely upon recreations of specific examples which those publications describe. They say those recreations show that the inevitable result of performing the examples is to produce lenses falling within the scope of the claims. In so far as the recreations involve deviations from what is described, the defendants say that those deviations are minor and entirely obvious.

The claimants meet these attacks by disputing that the defendants have faithfully recreated the examples and say that the modifications the defendants have made to the procedures described were not obvious. Moreover, they dispute that the lenses so created satisfy the material and clinical requirements of the claims.

In relation to Keogh, the defendants simply rely upon the disclosure itself. They say that example VI discloses all the features of most of the claims of the Patent and they advance a general case that it renders all of the other claims obvious. All these allegations are contested by the claimants.

In the result, the parties have disagreed on a considerable number of issues, many of them technical, which, in line with their submissions, I shall address in the following order:

Chang – disclosure and material properties. This involves a consideration of the teaching of Chang, whether the defendants’ recreations were a faithful or obvious implementation of the teaching and whether the material properties of the lenses so produced satisfy the requirements of the claims.

Lai – disclosure and material properties. This similarly involves a consideration of the teaching of Lai, whether the defendants’ recreations were a faithful or obvious implementation of the teaching and whether the material properties of the lenses so produced satisfy the requirements of the claims.

Chang and Lai – clinical properties. The lenses produced by the defendants were subjected to clinical tests conducted by Dr Brennan. They were tested together and it is convenient to consider the results of those tests in the same way.

Keogh. The issues here are more limited and simply involve a consideration of the disclosure.

Subsidiary claims – I consider the main issues arising on the subsidiary claims to the extent they have not already been addressed.

In developing their respective cases the parties did not address the allegations of lack of novelty and obviousness as entirely separate topics. In the light of the nature of the obviousness allegation, I too have adopted this course. But I would emphasise that in considering the merits of those cases I have had well in mind the different principles applicable to each. As for lack of novelty, I have followed the approach explained in Synthon to which I have referred. As for obviousness, the question to be considered is whether or not the differences between the cited art and what is claimed constitute steps which, when viewed by the person skilled in the art without any knowledge of the invention, constitute steps which would have been obvious or whether they required any degree of invention: Pozzoli v BDMO [2007] EWCA Civ 588; [2007] FSR 37. In so far as the defendants’ recreations departed from the teaching of Chang and Lai, this primarily requires a consideration of whether those departures were obvious.

Chang is a patent application published on 4 April 1991. It describes silicone hydrogel lenses containing a vinylic siloxane monomer in combination with hydrophilic monomers which, after manufacture, are subjected to a treatment which increases the number of hydroxyl acrylic monomer (“HAM”) units and reduces the number of silicon units on the lens surface.

Example 3 of Chang describes the production of a lens that was initially unsuitable for extended wear and which produced poor vision, discomfort and encountered serious deposition problems within four hours of wear. However, after surface treatment in accordance with the disclosure, it “could be used for weekly extended wear for a three week testing period with stable vision and no observable deposition, and demonstrated a liquid layer over the lens surface”. The defendants say it was therefore an ophthalmic lens with ophthalmically compatible inner and outer surfaces and suited to extended periods of wear. Moreover, it was made from polymerizable materials comprising TRIS, HEMA and DMA which fall within the Patent definition of oxyperm and ionoperm polymerizable materials. Further, it is said to have had a 38% water content and a high Dk, indicating, according to the defendants, that it would have an ion permeability within the limits of claim 1 and an oxygen permeability sufficient to maintain corneal health and wearer comfort.

As I have mentioned, the defendants’ case is not, however, based on the description of the example as such but rather upon the performance of it by Dr Vanderlaan. They say that the example gives clear and unmistakable directions to make a lens falling within the claims or, alternatively, it gives directions which, with trivial and obvious modifications, will result in the production of such a lens. The lenses created by Dr Vanderlaan were tested for ion permeability, oxygen transmissibility and in the clinic and the defendants say that all these tests show that the example destroys the novelty of the claims or renders them obvious.

The defendants’ case is challenged at every stage by the claimants who criticise Dr Vanderlaan’s method of preparation, dispute that his lens meets the oxygen permeability requirements of the claims and dispute that it was ophthalmically compatible over a period of extended wear.

Dr Vanderlaan described the preparation of the example 3 lens in his first report. Before dealing with the substance of the attacks made by the claimants on his methodology, I must address two preliminary issues. The first is that it emerged that Dr Vanderlaan had been engaged in preparing recreations of Chang for the purpose of parallel US proceedings for some considerable time before he was asked to provide an experimental protocol in connection with this action. Further, he accepted in the course of cross examination that he probably referred to that US work in drafting the UK protocol. This is a matter to which I must have regard in considering the various deviations from the Chang description which that protocol embodies.

The second is the approach taken by Dr Koßmehl and is a matter to which I have already referred in my assessment of him as a witness. He provided extensive criticisms of Dr Vanderlaan’s methodology in the form of an annex to his report, most of which was written by a Professor Mays who did not give evidence before me, and which appeared to take every conceivable point. The defendants say, and I agree, that this is not a helpful way in which to present expert evidence because it makes it much more difficult for the court to determine how those criticisms came to be formulated and the weight to be attached to them. Again, this is a matter which I have had well in mind in assessing the weight to be attached to Professor Koßmehl’s evidence.

I now turn to the specific criticisms of Dr Vanderlaan’s methodology. In the course of the trial attention was focused on some but not all of the criticisms made by Professor Koßmehl and in the discussion which follows I address those points to which the parties directed my attention in their closing submissions and following the cross examination of the experts.

The first concerns the process used by Dr Vanderlaan to make the lenses. Chang exemplifies lens production using thermal polymerisation to make rods, cutting them into buttons and then lathing the buttons to form lenses. There was some evidence that the defendants tried to implement Chang using this process but that they were not successful in producing lenses with the characteristics they sought. In the event, the recreations relied upon in these proceedings were made by cast moulding using photoinitiators and UV radiation to initiate polymerisation. It is not suggested by the claimants that these were inventive modifications in themselves, but I am satisfied they may well have had an effect on the properties of the resulting lenses. As I have explained, it was well known that the chemical and morphological structure of a lens and the topography of the finished lens material may be affected by whether it was made by lathing or cast moulding.

The second point is that Chang does not specify the use of any cross linker, yet Dr Vanderlaan used TRIS containing 6% of the cross linker TETRAKIS. In his first report Professor Koßmehl said this is a high level of cross linker which would make a denser polymer structure and tend to lower the water content and increase the oxygen permeability of any resulting lens. Professor Koßmehl also noted that when Dr Vanderlaan first used TRIS in connection with his US recreations of Chang, it contained a low level of cross linker as an impurity and that it was not until a year after his first recreation that he decided to experiment with a different grade of TRIS with a higher cross linker content. Under cross examination Professor Koßmehl accepted that all grades of TRIS contain quantities of cross linker and that it was sensible to use a grade of TRIS in which the level of cross linker was known. But he maintained that the levels used by Dr Vanderlaan were high and that this must have resulted in a change to the physical properties of the material.

Dr Vanderlaan disputed that a high level of cross linker was used and maintained both in his reports and under cross examination that they moved from one grade of TRIS to another because they thought it sensible to pick the one which contained a known concentration of cross linker.

I have no doubt that it was sensible to use a grade of TRIS which contained a known quantity of cross linker. But in the light of all the evidence I am also satisfied that the grade of TRIS chosen by Dr Vanderlaan did indeed have a relatively high level of cross linker, that this is not taught by Chang and that it may have affected the physical properties of the polymer and the resulting lenses. Accordingly I do not accept that the experiment represents the inevitable result of performing Chang. Nor does it represent an obvious modification of Chang.

The third point is that Dr Vanderlaan’s experimental protocol resulted in there being a substantial reduction in the amount of water in the reaction. Chang specifies the use of 96% glycerol, which contains 4% water, whereas Dr Vanderlaan used glycerol of much higher purity and lower water content.

Professor Koßmehl maintained in his report that this is important to the essential teaching of Chang which is seeking to address the high oxygen permeability but poor clinical performance of existing lenses. Chang’s solution is to increase the proportion of HAM units to silicon units in the surface layer of the lens and one of the ways he does so is by reacting the lens surface with a polyol in a base or acid medium. The stated aim of using a polyol in an acid or base is to increase the proportion of HAM units in the surface layer by transesterification and to reduce the silicon units by acid or base catalysed cleavage of the siloxane bonds, and the presence of water contributes significantly to these reactions at the surface of the lens during the treatment. By contrast, the 99.9% glycerol used by Dr Vanderlaan would, in Professor Koßmehl’s opinion, substantially reduce the effectiveness of the surface treatment of Chang. Further, and importantly, he would expect a lens with a lesser degree of hydrolysis and transesterification on its surface to be more permeable to oxygen.

Dr Vanderlaan disagreed. He thought there was no support in Chang for a conclusion that hydrolysis reactions should be part of the surface treatment. To the contrary, the skilled person would understand that the reaction conditions of example 3 will form glyceroxide and hydroxide as principal reactive species but that since the concentration of glycerol is far higher than that of water, the glyceroxide will be the dominant reactive species. Glyceroxide will result in the substitution of siloxane groups with glycerol groups at the surface via transesterification which will increase the HAM units in the surface layer. It may also result in the acid or base catalysed cleavage of siloxane bonds.

This has not been an easy dispute to resolve but my conclusions are these. First, I understood the experts to agree that the skilled person would understand that both transesterification and hydrolysis reactions will be occurring, but the relative importance of each will depend on the degree of purity of the glycerol. Second, I do not believe there is anything in Chang to suggest that the glycerol must contain 4% water for the purpose of promoting a hydrolysis reaction. Third, nevertheless, a faithful reproduction of Chang would have involved the use of glycerol containing 4% water. Fourth, I am satisfied on the evidence that the presence of water at a level of 4% is likely to have had an effect on the overall balance of the reactions taking place and this is something the skilled person would have appreciated. Fifth, how great that effect was and its impact on the properties of the treated lens are matters which it is not possible to determine on the materials before me. But I can say that this is another respect in which the defendants’ experiment did not reproduce example 3 of Chang and in my judgment it was not an obvious modification to make.

The fourth point is closely related to the third. Example 3 calls for the surface treatment to be carried out on a lens in a dehydrated state. That is what Dr Vanderlaan did. However, the claimants contend that he should have first hydrated and then dehydrated the lens as described in example 2, that this additional step is necessary to remove unreacted materials, and that the process of hydration and dehydration would be expected to lead to the presence of water because it is very difficult to dehydrate a lens completely.

Despite a lengthy cross examination of Dr Vanderlaan, he did not accept the omission of the hydration and dehydration step might have had a material effect on the properties of the lens and Professor Koßmehl did not make much of the point either. In the light of the evidence as a whole I do not believe this criticism has any substance.

Finally, the claimants say that Dr Vanderlaan took unusual steps to terminate the reaction rapidly. Specifically these involved placing the lens in an excess of buffer solution and vigorously shaking it. This, say the claimants, was not an obvious thing to do unless some other thinking or purpose lay behind it. They continue that it is, however, consistent with a deliberate attempt to minimise hydrolysis reactions by ensuring that the sodium hydroxide (already present in the reaction mixture) and water (added to terminate the reaction) were in contact with the surface of the lens for as short a time as possible.

I reject this criticism too. Dr Vanderlaan explained, and I accept, that he wanted to bring the reaction to an end as quickly as possible because up to this point it had been proceeding only at the surface of the lens. However, he appreciated the water added to terminate the reaction would be absorbed by the lens together with the other reaction components and this had the capacity to degrade the chemical units inside the lens, which would not have been desirable. In all these circumstances it seems to me it was entirely reasonable and obvious to place the lens in an excess of buffer solution and shake it vigorously.

In summary, many of the criticisms of Dr Vanderlaan’s work are not justified. But a limited number do have substance. Accordingly, I do not accept that the recreations were a faithful implementation of Chang. They involved deviations which may have had a material effect on the properties of the lenses produced. Nor do I accept these deviations were obvious ones to make.

The Chang lenses were tested for ion permeability and oxygen transmissibility.

Professor Freeman measured the ion permeability of the lenses using the Ionoflux technique of the Patent. He recorded Ionoflux values of 3.63 x 10^-3 mm²/min which is well above the minimum called for by claim 1.

Professor Benjamin measured the oxygen permeability of the lenses using the coulometric method and the Dk1000 machine referred to in the Patent. This is a technique and piece of apparatus which is not much used. Indeed Professor Benjamin believes that at the time of the filing of the Patent, the claimants and their collaborators were the only persons using the coulometric method in the whole of the contact lens industry. In brief summary, a dry gas is passed across the back surface of a lens in order to pick up oxygen molecules that have permeated through the lens. The oxygen molecules are then carried in the gas stream to a coulometric detector. This measures a voltage that is proportional to the concentration of oxygen in the gas stream passing through it.

Professor Benjamin took what were referred to as “single point” measurements having first calibrated the machine using commercially available FND lenses, for reasons I elaborate below. He found the Chang lenses had an average thickness of 71 microns and a mean single point transmissibility of 60.01 barrers/mm.

This value is, of course, outside the limit of claim 1 of the Patent which calls for an oxygen transmissibility of at least 70 barrers/mm. However, the defendants point out that Chang teaches the lenses should be 50 to 80 microns thick. It follows, they say, that if the lenses were 60 microns thick they would have an average transmissibility of 72 barrers/mm and if 50 microns thick they would have an average transmissibility of 86/barrrers/mm – both being within the limits of the claim.

The problem with this approach is that it takes no account of what is known in the art as “the boundary layer effect”. This is an experimental artefact resulting from a layer of water in contact with the lens which adds additional resistance to the passage of oxygen. However, the boundary layer effect does not change in proportion to the thickness of the lens. To the contrary, it stays the same. So the greater the thickness of the lens, the less the relative importance of the effect. In order properly to discount the boundary layer effect it is therefore necessary to take measurements across a range of thicknesses and carry out a regression analysis. But that is not something that any of the parties to the present case have attempted to do.

Professor Benjamin gave evidence that, as a result of the boundary layer effect, one cannot simply scale the transmissibility of a lens of a particular thickness in order to determine the transmissibility of a lens of a different thickness. He put it this way on day 10, page 1294:

Yet that is exactly what the defendants have done. I conclude it has not been established that lenses made in accordance with example 3 of Chang and having a thickness of 50 or 60 microns would have an oxygen transmissibility of at least 70 barrers/mm as called for by claim 1 of the Patent.

Lai is an international application by B&L which was published in 1993. It describes improved wettable polymeric hydrogel formulations for making lenses and teaches the production of a silicone hydrogel lens formed from a polysiloxane urethane macromer and TRIS in combination with hydrophilic monomers or wetting agents. It is notable that Lai teaches that any known silicone containing prepolymer may be used to form the silicone hydrogels of his invention.

The defendants focus their attention on example 4. This describes the production of a hydrogel film comprising a polysiloxane containing urethane prepolymer (“IDS3H”) and TRIS, both of which are oxyperm polymerizable materials according to the Patent, together with NVP, DMA and a HEMA derivative (“HEMAVc”), all of which are ionoperm polymerizable materials according to the Patent.

The defendants’ case again rested upon the performance of the example by Dr Vanderlaan. The defendants say lenses were made by him in accordance with the example. These recreations were tested for ion permeability, oxygen permeability and in the clinic. The defendants contend this work demonstrates that Lai destroys the novelty of all the claims or renders them obvious.

The claimants say the work of Dr Vanderlaan did not faithfully reproduce example 4, and dispute that his recreations had the material and clinical properties called for by the claims.

Dr Vanderlaan described how he made the lens material in his first statement. All the ingredients were commercially available except HEMAVc and IDS3H. No particular issue arises in relation to the former, but the latter caused a good deal of controversy. Once again Professor Koßmehl identified a series of criticisms of Dr Vanderlaan’s work in his report, only some of which were still pursued at the end of the hearing. I will address them in turn.

The first and most fundamental objection concerns the production of a hydroxyl terminated polysiloxane diol (“PDMS diol”), which is an ingredient used to make the IDS3H macromer. Lai does not provide any guidance as to how the PDMS diol is to be made and I am satisfied Dr Vanderlaan attempted to make it six times from November 2005 but without success. One of the problems he encountered was a hazy reaction product of inadequate molecular weight which made it unsuitable for lens production. Eventually he turned to a commercial source, Shin-Etsu, which he had apparently heard about through the claimants, and from which he obtained an alternative. That product, KF-6002, contains propyloxyethyl end groups rather than the hydroxyethyl end groups taught by Lai, and this was something which Professor Koßmehl considered significant and which might have an effect on the character of the resultant IDS3H, a view which he maintained under cross examination.

In my judgment this criticism is justified. I am not satisfied that Dr Vanderlaan’s programme of work represents the path the ordinary skilled person would have taken in seeking to reproduce example 4 of Lai at the date of the Patent. Nor am I satisfied he would have found or adopted KF-6002 from Shin-Etsu. There were many other avenues to explore.

I can address the other criticisms quite shortly. The claimants say that Dr Vanderlaan used the wrong catalyst and solvent to synthesise the IDS3H. I do not accept this was so. Dr Vanderlaan used methylene chloride and dibutyltindilaurate (“DBTDL”), both of which are described in another patent US 5,034,461, which is referred to in Lai.

Finally, the claimants say that an excess of HEMA was not added. Dr Vanderlaan explained, and I accept, there is nothing in this complaint. Its purpose is to ensure complete reaction of isocyanate groups but was not necessary in the preparation of IDS3H given Dr Vanderlaan’s knowledge of the molecular weight and mass of each of the components he used.

Professor Freeman measured the ion permeability of the lenses using the Ionoflux technique of the Patent. He recorded Ionoflux values of 1.19 x 10^-3 mm²/min which is well above the minimum called for by claim 1.

Professor Benjamin was asked to determine the oxygen transmissibility of the lenses. They had a thickness of 83 microns and he recorded their oxygen transmissibility as 88.25 barrers/mm. Again, on the face of it, this satisfies the claim.

There was, however, a substantial issue between the parties as to whether the Dk1000 machine required calibration. Professor Benjamin explained in his first report that theoretically different operators using different Dk1000 machines should achieve the same Dk value for the same lens material and the same Dk/t value for the same lens. However, he continued, practically speaking the devices are not identical and nuances in their use are not amenable to perfect replication. Thus different operators using the same or different devices are not able to produce the same Dk value for the same material and the same Dk/t value for the same lens and the differences are not insignificant. This is a common problem with analytical devices and one that is generally dealt with by having a detailed test protocol or method of calibration.

Professor Benjamin therefore attempted to calibrate the Dk1000 machine he used. For this purpose he referred to the Dk1000 manual and noted that it includes a term “Q” which the manual describes as a calibration factor. He also reviewed the ASTM standard which is referred to in the manual and which states that measurements made on a coulometric device should be calibrated. However, he faced the problem that calibration requires the use of a standard reference material of known Dk and no industry accepted standard soft contact lens material exists for use with the coulometric method. So Professor Benjamin turned to the claimants’ FND product because Dr Nicolson, one of the named inventors, had testified in the parallel US proceedings that this had a Dk of 95 barrers.

Dr Port expressed the contrary view. In his second report he explained that the Dk 1000 machine does not need calibration because it has a high basic efficiency and that the use of the FND product as a reference material may have introduced error because the Dk figure of 95 barrers is only a rough average.

Both experts were cross examined extensively on the issue. Professor Benjamin essentially maintained his position although he accepted that “Q” also acts as a unit conversion factor. Dr Port accepted some of the general propositions advanced by Professor Benjamin to the effect that devices are not identical, different machines may produce different values for the same material and the problem is common to analytical devices in general. However he also maintained that the Dk1000 machine purported to give absolute values and it was therefore not necessary to calibrate it.

I have come to the following conclusions in the light of all this evidence. First, I accept the general desirability of calibrating analytical instruments. Second, the Dk1000 manual itself is ambiguous as to whether the machine should be calibrated. Although it refers to the term “Q” as a calibration factor, it also states clearly that the Dk1000 is accurate and does not need calibration. Moreover, as Professor Benjamin accepted, “Q” has another function in any event as a unit conversion factor. Third, and importantly, neither the Patent nor the manual identifies any reference material which should be used for the purpose of carrying out a calibration exercise and there was no obvious material for the skilled person to turn to. Fourth, it follows that the skilled person reading the Patent might reasonably conclude there was no need to calibrate the Dk1000 absent some evidence that the machine was not working properly or efficiently, and there was no such evidence in relation to any of the Dk1000 machines used for the purposes of the experiments deployed in this case. Fifth, that does not, however, mean to say that carrying out a calibration exercise will lead to the introduction of material errors. It will only do so if the reference material used for that purpose has been incorrectly characterised. Sixth, I have reached the conclusion that Professor Benjamin acted reasonably is seeking to calibrate the Dk1000 used in his experiments by reference to the FND lenses and that the results he obtained are reliable. Although the claimants sought to suggest the calibration exercise had introduced the possibility of significant error, I am not persuaded that was the case.

I therefore accept the Lai recreations had an oxygen transmissibility of in excess of 88 barrers/mm.

The defendants also dispute that the Chang and Lai recreations were ophthalmically compatible over a period of extended wear. As a result they were subjected to clinical tests which took place in Australia under the supervision of Dr Brennan. He carried out two sets of experiments. The first, referred to as “Part I of the Brennan Study” formed the basis of the first notice of experiments dated 16 June 2008. The second, referred to as “Part II of the Brennan Study” formed the basis of an amended notice of experiments dated 28 August 2008 and was witnessed by Dr Port, Dr Brennan and the solicitors for the parties. Part I used a 21 to 22 hour study period. Dr Brennan considered this to be adequate because the critical period for assessment of a lens to be used in extended wear is a reasonable period of daytime wear plus overnight wear and he did not expect it to make a difference whether the total period was 21 or 24 hours, so long as a period of overnight wear was included. Nevertheless the claimants apparently requested a test period of at least 24 hours duration and this is what Dr Brennan therefore did in the repeat which formed the substance of Part II.

The procedure adopted for the repeat was, in summary, as follows. On attending the clinic for the lens-wearing session, the eligible subjects were assessed and then a lens, determined according to a randomised schedule, was applied to the non-dominant eye by the investigator and allowed to settle for approximately 30 minutes. The lens fit was video recorded, the lens on the eye was photographed, and lens movement and deposition on the lens were assessed by the investigator. Lens movement was recorded in millimetres of movement for both primary and upward gaze positions. Lens deposition was graded as either none, slight, mild, moderate or severe and visual acuity was measured.

After approximately four hours and then again after about 12 hours, the subjects were re-examined. The eyes were then masked and each subject went to sleep wearing the contact lens. After about eight hours of closed eye lens wear, the subjects were woken and corneal thickness was measured and, a little while later, lens movement and deposition were assessed. The subjects then reported on comfort of the lenses. They were asked: “while you are wearing the lens was your comfort acceptable?” and “while you were wearing the lens, were you free of substantial discomfort?” The subjects could respond with either a “yes” or “no” answer. A final evaluation was then performed to confirm that the subjects were able to leave without any negative consequence from the period of lens wear.

A total of 15 subjects were enrolled in the study and 13 successfully completed it. Of these, six were fitted with the Chang recreations and seven with the Lai recreations. One man dropped out prior to lens dispensing because he was found to be suffering from corneal inflammation and another was discontinued after four hours when it was discovered he had been wearing the lens inside out.

Corneal swelling occurred in all subjects after overnight wear. In the case of the Lai lenses the average increase in corneal thickness was 4.8% and in the case of the Chang lenses it was 5%. The highest percentage increase for all the subjects was 8.8% and the lowest was 1.5%. In both cases a Lai lens was being worn.

I have discussed this component of ophthalmic compatibility at paragraphs [67] and [99]. In my judgment the degree of swelling seen in the subjects of the study is well within the range contemplated by the Patent as being acceptable. In this regard it is notable that the Patent states at paragraph [0040] that it was known that the cornea swells approximately 3% to 4% during overnight periods of sleep when the eyelids are closed, as a result of oxygen deprivation. It was also known that wearing a typical contact lens, such as the defendants’ Acuvue lens, for a period of about eight hours caused corneal swelling of about 11%.

Before leaving this issue I should, however, mention that the claimants focused considerable attention upon one of the subjects in Part 1 of the study who showed overnight corneal swelling of 17.3% while wearing a Chang lens. This was much higher than any other subject wearing that lens type and, as Dr Brennan explained, the subject had reported a previous medical condition of hydrocephalus. I am satisfied that this is an outlier and so far from the data for the remainder of the group of Chang lens wearers that no real significance can be attached to it.

Movement on the eye was measured at 30 minutes, 4 hours and 24 hours. As Dr Port accepted, adequate movement for ophthalmic compatibility is 0.1-0.4 mm. There were only two cases where the lens did not move to this extent and in both cases it was found that the lenses were not adherent and could be decentred by digital manipulation without undue force. I am satisfied on the evidence that the movement on the eye of the Chang lenses and the Lai lenses was generally good.

Turning to comfort, all patients wearing the Chang lenses responded that their level of comfort was acceptable and that they were free of substantial discomfort. The same was true of the subjects wearing the Lai lenses save that in one case the subject said he was not free of substantial discomfort. Overall I am satisfied that both lenses satisfy the requirement of comfort.

As for ocular health, two subjects wearing the Lai lenses were observed to have a measure of conjunctival injection, a condition in which the blood vessels of the conjunctiva and limbal region of the cornea typically carry little or no blood. There were also comments by the attending clinician of two moderate gradings for conjunctival indentation. In the light of the evidence I do not consider these significant and Dr Port accepted that, leaving aside the issue of deposits, he would not say that the results showed the lenses to be clinically unacceptable.

As for lens deposits, the report of Part II records that no severe deposit gradings were found in any of the Chang or Lai lenses. Moderate deposits were found on the front surface of one lens of each type before sleeping and one moderate deposit was found on the front surface of a Lai lens after waking. The claimants also focused on two further subjects from Part I. In one case the front surface of a Lai lens received a severe grading for deposition immediately prior to sleeping. In the case of this particular subject, the deposition was apparent soon after lens insertion and took the form of a fingerprint on the lens. Dr Brennan considered it possible that a substance such as moisturiser had been transferred to the lens immediately prior to insertion. In the other case, the subject was also wearing a Lai lens and was discontinued because his lens had serious back surface deposits.

At the end of the day, it was the issue of deposits which caused Dr Port the greatest concern. He maintained that in the case of both the Chang and Lai lenses deposition occurred so quickly and the deposits were so substantial that he doubted whether the lenses were clinically acceptable and, in his view, neither would form the basis of a commercially successful lens.

Dr Brennan was much more robust. He expressed the view that both the Chang and the Lai lenses were ophthalmically compatible. He noted the majority of the deposit gradings were mild or less, observed that he would have found the lenses interesting and considered that they could be the basis for commercial lenses.

The Patent is not of much help in seeking to resolve this difference between the experts. It provides very little guidance as to where the line is to be drawn between acceptable and non-acceptable lipid deposition. I also have in mind that Dr Brennan explained that all contact lens types are susceptible to deposits, that standard hydrogel lenses available in 1995 would typically develop low levels of deposition but that silicone elastomer lenses such as B&L’s Silsoft lens would typically attract much higher levels of deposition. With this in mind, I do not believe the skilled person would have considered the deposition seen in the Chang and Lai recreations as being so great that they should not be taken forward. To the contrary, I believe the skilled person would have considered them to be satisfactory working prototypes.

I conclude that both the Chang and the Lai recreations are ophthalmically compatible during a period of extended wear as called for by claim 1 of the Patent.

The work the defendants have carried out does not represent the inevitable result of performing example 3 of Chang; nor does it involve variations which have been shown to be obvious as of 1995. Moreover, I am not satisfied that lenses made in accordance with example 3 would meet the oxygen transmissibility requirements of the claim or that they would do so with only obvious modifications.

The attack on the Patent based on Chang therefore fails.

The work the defendants have carried out does not represent the inevitable result of performing example 4 of Lai. In particular, Dr Vanderlaan’s attempts to produce the PDMS diol were not successful and I am not satisfied it was obvious to turn to Shin-Etsu and use their KF-6002 product as an alternative.

The attack on the Patent based on Lai therefore fails

Keogh was published on 7 April 1981 and describes a water absorbing, soft, hydrophilic, flexible, fillerless, hydrolytically stable, biologically inert contact lens with the capability of transporting oxygen sufficiently to meet the requirements of the human cornea.

Keogh elaborates the problem which it seeks to address in much the same terms as the Patent. At the outset it explains the benefit of the polysiloxane materials as being oxygen permeable and soft. However, soft contact lenses made from known polysiloxane materials did not “ride” on the cornea on a layer of tears but rather attached themselves to the cornea in such a way as to alter the metabolism of the eye and, on occasion, cause physical damage.

Keogh’s solution is described at column 14, line 16-33:

Professor Valint expressed the opinion in his first report that this passage shows that Keogh and the Patent are attempting to solve the same problem by the same means. He then focused his attention on example VI which describes a contact lens comprising a polymerizable polysiloxane component and a polymerizable acrylate component. Using the terminology of the Patent, these are oxyperm and ionoperm polymerizable materials respectively.

Professor Valint then reasoned in his report as follows. The lens of example VI is said to have an oxygen permeability of 67 barrers. Although Keogh does not specify the thickness of the lens produced in example VI, at thicknesses up to approximately 100 microns, which would be a typical lens thickness at the time of Keogh, the oxygen transmissibility of the lens would be at least about 70 barrers/mm. He also referred to and agreed with the opinion expressed by Professor Freeman that, on the basis of an 18% water content by weight, the lenses of example VI would have an ion permeability of greater than 1.5 x 10^-6 mm²/min.

As for ophthalmic compatibility, Professor Valint pointed out that Keogh explains that clinical tests were carried out in which the lens was worn by a monkey for 24 hours without trauma. Monkeys, he continued, are excellent models for humans and, if a lens can be worn for 24 hours without trauma by a monkey, that is strong evidence that it is ophthalmically compatible and suited to extended periods of wear by a human. He concluded that example VI of Keogh discloses all the features of claim 1 of the Patent.

I am not persuaded the position is so straightforward. Professor Benjamin accepted in the course of cross-examination that Keogh has measured oxygen permeability using a different method from the coulometric method described in the Patent. More importantly, he also agreed that the oxygen permeability values given in Keogh are dubious because it reports that the material of example X was found to have a higher oxygen permeability than that of example V. This is an unlikely finding, since example V contains a significantly higher amount of silicone monomer and would therefore be expected to have a higher oxygen permeability, a view which Dr Port shared. Accordingly, I do not believe it can be assumed that there is a correlation between the oxygen permeability results described in Keogh and those of the Patent.

Second, I do not accept that a lens worn for 24 hours without trauma by a monkey is necessarily ophthalmically compatible and suited to extended periods of wear by a human. Dr Port considered the monkey experiment was unlikely to be reflective of clinical performance in humans and, when this was put to Professor Valint, he could only offer the comment that he had been informed that to carry out experiments on monkeys was fairly standard practice at the time of Keogh and that clinicians used this type of experiment for initial evaluation.

Third, Keogh was plainly seeking to make a lens which was sufficiently hydrophilic and water absorbing to ensure that it not only did not stick to the eye but also moved sufficiently during normal wear to preserve normal corneal metabolism. However, the monkey experiment aside, there is no evidence that a lens made in accordance with example VI does in fact move in that way or that it solves the problem of poor wettability. Professor Valint did not know of any publication prior to 1995 which suggested or demonstrated that Keogh’s invention had found any practical application, despite its assignment to B&L.

I conclude that Keogh does not destroy the novelty of claim 1 of the Patent. Further, it has not been shown that obvious modifications to the disclosure would result in the production of a lens falling within the scope of claim 1. The attack based on Keogh therefore fails.

In light of the foregoing it is not necessary to address the subsidiary claims, but I will express my conclusions shortly in relation to those claims to which the parties directed my particular attention.

These claims require a higher threshold for oxygen permeability of 75 barrers/mm in the case of claim 4 and 87 barrers/mm in the case of claim 5. So far as Chang and Keogh are concerned, the case of anticipation and obviousness fails for the reasons I have given in relation to claim 1. So far as Lai is concerned, the recreations of example 4 had an oxygen permeability which satisfied both of these claims.

These claims relate to morphology and the presence of continuous pathways. No attempt has been made to show that the Chang or Lai recreations had the necessary morphology. Nor is there any teaching directed to morphology in Keogh.

The limitation introduced by these claims relates to water permeability as measured by the Hydrodell technique. As I have said, the patent teaches that water permeability is believed to be directly proportional to ion permeability. The limitation adds nothing beyond the introduction of another parameter.

These claims are directed to lenses in which the surface is more hydrophilic than the core. I have addressed this issue in considering the common general knowledge. The concept of surface treatment was known, as were various methods of carrying such a treatment out, including those of Yasuda. But their effectiveness in the context of a silicone hydrogel lens suitable for extended wear had not been established. Lai and Keogh contain no teaching over the common general knowledge. So far as Chang is concerned, this does teach surface treatment in which the proportion of hydrophilic groups to silicon units on the surface is increased. The purpose of that treatment is plainly to make the surface more hydrophilic. Chang also teaches that a number of other treatment methods may be used, including plasma treatment.

In summary, the Patent teaches nothing more in respect of surface treatment than the common general knowledge and Chang, but I do not accept that this made it obvious how to make silicone hydrogel lenses suitable for extended wear. This is a matter to which I return in addressing insufficiency.

These claims are directed to the use of a siloxane containing macromer and a siloxane containing monomer such as TRIS. The claims contain limitations to macromers having a particular molecular weight and glass transition temperature and to compositions in which the oxyperm macromers, oxyperm monomers and ionoperm monomers are present in particular ratios. I am satisfied these are taught by each of Lai and Keogh or, as Professor Valint explained, are merely obvious variants of their teaching.

These claims relate to clinical criteria. The Chang and Lai lenses created by the defendants meet the requirements of claims 46 to 48 and 50, but not claim 49. Further, it has not been shown that the recreations would satisfy the periods of extended wear of 4 to 30 days called for by claims 51 to 54, nor that such lenses were obvious.

These are directed to lenses with a particular tensile modulus, relaxation time and tan delta. Professor Valint referred to the teaching of the Patent that in order to have appropriate on-eye movement, a lens preferably meets the claimed threshold in respect of these mechanical parameters. More importantly, the Patent teaches at paragraph [0096] that on-eye movement may be predicted from the mechanical properties, the ion or water permeability through the lens, or both the mechanical properties and ion or water permeability. In light of that teaching and the experimental analyses of the recreations, I think it likely that the recreations did indeed meet the claim thresholds for these various mechanical parameters.

The defendants contend that the teaching of the Patent does not provide sufficient information for the person skilled in the art to make lenses falling within the claims without undue experimentation. Further, they continue, even if it is apparent how to make some lenses falling within the claims, it is not apparent how to make lenses falling within the claims using all the materials covered by the claims and they are thus not enabled across their breadth. Regardless of whether the skilled person adopts the screening methods underlying claim 1 (ion permeability and oxygen transmissibility) or claims 8 or 11 (ion permeability and oxygen transmissibility plus co-continuous phases/pathways), the specification does not provide a solution to the known problem of identifying a suitable material from which to make a lens which will meet the functional requirement of ophthalmic compatibility over a period of extended wear.

The defendants contend that this broad proposition is established on the evidence but that the position is made yet worse for the claimants by the following further matters. First, it is not possible to tell from a reading of the Patent which, if any, of the examples fall within claim 1 – although it is apparent that some do not. Second, the claimants themselves contend that in order to tell if a lens is made in accordance with the invention and satisfies the requirements of the claims, it is necessary to conduct substantial clinical trials on human subjects for periods of up to 30 days. Third, the Patent contains no teaching of a common principle of manufacture which would enable the skilled person to make lenses across the scope of the claims. Before elaborating each of these points I must first say a little about the law.

It is a ground for revocation under section 72 of the Act (corresponding to Art 83 EPC) that the specification does not disclose the invention in a manner sufficiently clear and complete for it to be performed by a person skilled in the art. The meaning of this requirement has attracted a good deal of judicial attention and certain principles of relevance to this case are now well established.

The first is that the specification must enable the invention to be performed to the full extent of the monopoly claimed. As Lord Hoffmann explained in the House of Lords in Biogen v Medeva [1977] RPC 1 at pages 48-49:

In the more recent cases of Kirin Amgen Inc v Hoechst Marion Roussel Ltd [2005] RPC 169 and Generics (UK) Limited v Lundbeck [2009] RPC UKHL 12, the House of Lords has reaffirmed this basic requirement.

It has also found expression in the case law of the EPO in considering inventive step under Article 56 EPC. In case T 939/92 Agrevo, the Board of Appeal considered a claim to a group of chemical compounds said to have herbicidal activity. The appellant patentee argued that the only question was whether a skilled person would have prepared or tried to prepare the claimed compounds. The board disagreed. It re-emphasised that the extent of the monopoly must correspond to and be justified by the technical contribution. Hence the issue of obviousness must be decided having regard to the technical problem the claimed invention sets out to solve on the basis of an objective assessment of the technical results achieved by the claimed subject-matter. If the claimed compounds do not have any technically useful property then the technical problem which is solved is simply the provision of further chemical compounds regardless of their chemical properties, and that is not inventive. It follows, said the board, that a technical effect which justifies the selection of a class of claimed compounds must be one which can fairly be assumed to be possessed by substantially all those selected compounds (at paragraph 2.5.4). It must be credible that substantially all of the claimed compounds possess the relevant activity. It is only in these circumstances that a technical problem can be accepted as having been solved (at paragraph 2.6). This may be the case if it possible to make a reasonable prediction of a relationship between structure and activity (at paragraph 2.6.2).

The second principle is that whether the specification discloses an invention clearly and completely enough for it to be performed by a person skilled in the art involves a question of degree. It is impossible to lay down any precise rule because the degree of clarity and completeness required will vary depending on the nature of the invention and of the art in which it is made. On the one hand, the specification need not set out every detail necessary for performance. The skilled person must be prepared to display a reasonable degree of skill and use the common general knowledge of the art in making routine trials and to correct obvious errors in the specification, if a means of correcting them can readily be found. Further, he may need to carry out ordinary methods of trial and error, which involve no inventive step and generally are necessary in applying the particular discovery to produce a practical result. On the other hand, he should not be required to carry out any prolonged research, enquiry or experiment: Mentor Corporation v Hollister Inc. [1993] RPC 7.

Inventions which are claimed by reference to the results to be achieved often provoke a good deal of suspicion that they are merely an attempt to monopolise all ways of solving a known problem. They are also inherently less clear in their scope than claims which are defined by physical features. At least for this latter reason, the EPO does not generally allow such claims unless the invention can only be defined in such terms or cannot otherwise be defined without unduly restricting the scope of the claims. Nevertheless, in terms of enablement there is, in my judgment, no reason to treat them any differently from other claims.

Hence in No-Fume v Frank Pitchford (1932) 52 RPC 231, a decision under the Patents and Designs Act, 1932, the Court of Appeal rejected an allegation of insufficiency in respect of a patent for an improved ash tray which comprised a trapping space to prevent the escape of smoke. The claim defined the device by reference to certain physical features and the functional requirement that it must retain the smoke. The court concluded that the specification contained a sufficient explanation for those in the art to make a device which worked by reasonable trial and error and without invention. As Lord Hanworth M.R. said at page 238:

In American Home Products Corporation v Novartis Pharmaceuticals UK Ltd [2001] RPC 8, the Court of Appeal again considered the question of sufficiency of a claim limited by function, but this time under the 1977 Act and in the context of pharmaceuticals. Professor Calne, the patentee, discovered that rapamycin, a known antibiotic, was useful to suppress transplant rejection. Because rapamycin was a known product, it could not be patented; nor could its use as a treatment. So Professor Calne secured a claim in the “Swiss” form to the use of rapamycin for the preparation of a medicament for the inhibition of transplant rejection and licensed it to American Home Products (“AHP”). Some time later, Novartis, a competitor, produced a derivative of rapamycin, called SDZ RAD, and began to use it for the same purpose. Infringement proceedings followed. The trial judge found in favour of AHP and Professor Calne and construed rapamycin as including derivatives with the result that the functional words in the claim limited its scope to derivatives which were suitable for the claimed purpose. On appeal, the main issue before the court was the question of infringement. Novartis argued the judge was wrong to construe the patent as he did, but if he was right then the patent was invalid for insufficiency.

The Court of Appeal reversed the finding of infringement. Aldous LJ, who gave the principal judgment, held that the skilled person who read the specification would not be able to predict with any certainty which derivatives would have the appropriate effect. Professor Calne had only discovered and described the second medical use of rapamycin. It was left to others to find out which derivatives worked. A claim which covered such derivatives would have been speculative and the patent should not be so construed.

Importantly for present purposes, Aldous LJ also considered that if the claim were to be construed in the way contended for by the claimants then it would be invalid for insufficiency. It was not possible to predict which derivatives would have immunosuppressant activity so it could not be said that the class had a unifying characteristic. As he elaborated at paragraphs [36] to [37]:

After referring to Mentor, he continued at [40] to [44]:

The reasoning of Aldous LJ in these paragraphs is, I think, a development of his earlier conclusion that Professor Calne had not identified a unifying characteristic of the class of derivatives which worked and which would serve to distinguish them from those which did not. As a result, the exercise of finding useful derivatives was unpredictable and iterative. Such an exercise could not be described implementing the invention. To the contrary, it was research with an uncertain outcome or, to adopt the words of Lord Hoffmann in Biogen, Professor Calne had not demonstrated a common principle by which the rapamycin effect would be shared by other derivatives. In these respects I understand the court to have a drawn a distinction between the circumstances of the case before it and those of a case such as No-Fume where the invention, albeit defined partly by function, was something the skilled person could implement without undue difficulty and by routine trial and error. There it was reasonably clear to the skilled person in the light of the teaching in the specification how to set about producing a device within the scope of the claim.

It follows, in my judgment, that a claim to a class of products said to possess a useful activity must be based upon the identification of a common principle which permits a reasonable prediction to be made that substantially all the claimed products do indeed share that activity. Further, it is not permissible to by-pass that requirement simply by adding a functional limitation which restricts the scope of the claim to all the products which do have the relevant activity, that is to say all those which “work”. In the case of a claim limited by function, it must still be possible to perform the invention across the scope of the scope of the claim without undue effort. That will involve a question of degree and depend upon all the circumstances including the nature of the invention and the art in which it is made. Such circumstances may include a consideration of whether the claims embrace products other than those specifically described for achieving the claimed purpose and, if they do, what those other products may be and how easily they may be found or made; whether it is possible to make a reasonable prediction as to whether any particular product satisfies the requirements of the claims; and the nature and extent of any testing which must be carried out to confirm any such prediction.

It will be recalled that the Patent explains that the object of the invention is the provision of an ophthalmic lens having a balance of oxygen permeability, ion permeability, on-eye movement and tear exchange, all of which are sufficient for periods of extended wear.

Such a lens is said to be provided by claim 1. As I have explained, the claim contains certain qualitative limitations relating to ophthalmic compatibility over a period of extended wear which means it only encompasses those lenses which do fulfil the object of the invention. But it also contains quantitative criteria relating to oxygen transmissibility and ion permeability. Indeed these are the only quantitative criteria underpinning all the claims.

As for oxygen transmissibility, claim 1 requires the lens to have an oxygen transmissibility of at least about 70 barrers/mm. But, as the claimants recognise, it had been known since the seminal study of Holden and Mertz in 1984 that lenses are required to have good oxygen transmissibility properties to ensure the cornea is not deprived of oxygen.

This makes the requirement of ion permeability of particular importance. The claimants say they have identified ion permeability as an important property of a lens and that, unexpectedly, ion permeability has been found to correlate well with, and is a predictor of, on-eye movement. Paragraphs [0054] to [[0056] of the specification (set out at paragraph [74] above) relate that the permeability of ions is believed be directly proportional to the permeability of water and above a certain threshold of permeability through a lens, the lens will move on the eye, and below the threshold the lens will adhere to the eye. Thus, contact lenses which achieve the balance between oxygen and ion permeability can be made which are suitable for extended wear use.

As I shall elaborate, the defendants say that the specification sets a puzzle because merely finding a material which has the oxygen transmissibility and ion permeability characteristics required by the claim is plainly not sufficient to work the invention. It is still necessary to carry out clinical tests to determine whether the lens is ophthalmically compatible over a period of extended wear, and that is so even for the examples described in the Patent which are said to have shown on-eye movement. But, they continue, the difficulties faced by the skilled person are compounded by the fact that the teaching of the specification and limits of the claims with respect to ion permeability are of no practical use. A material satisfies these limits if it has an ion permeability in excess of certain thresholds when measured either by the Ionoton or the Ionoflux techniques. The thresholds in respect of Ionoton are set so high that practically nothing will pass and in respect of Ionoflux are set so low that practically nothing will fail.

In assessing these rival positions, I must begin by saying a little more about ion permeability as a polymer characteristic.

Professor Freeman explained in his first report that ion permeability correlates to water permeability and to water content. He supported that opinion with numerous publications and studies. He was cross examined at considerable length and accepted that the chemical composition of a polymer has an influence on its ion permeability, but maintained that water content was the strongest variable. It provides a “ball park” figure. The following passage from his cross examination on day 10, at 1377 to 1379 upon which the defendants particularly rely gives a fair flavour of his evidence:

On behalf of the claimants, Dr Nicolson accepted that, at least with some silicone hydrogels, there is a general correlation between water content and ion permeability in that they change in the same direction.

Professor Koßmehl took a contrary view. He disputed Professor Freeman’s views both generally and in relation to silicone hydrogels. In the course of his cross examination he was taken through a large number of documents recording research undertaken by the claimants and I understood him to modify his position to the extent that he accepted that ion permeability depends both on the nature of the polymer and the water content.

So, in the end, I think the difference between the experts was one of emphasis. Overall, I found the evidence of Professor Freeman persuasive and he was well qualified to assist me on this issue. I am satisfied there is a broad correlation between water content and ion permeability of silicone hydrogels but that the precise value of the ion permeability of any particular polymer will also depend upon its chemical composition.

This finding is, in my judgment, of some importance. Those in the art had attempted for some time to produce a silicone hydrogel lens suitable for extended wear by balancing water content against oxygen permeability. Now the Patent teaches the skilled person to consider ion permeability and oxygen transmissibility. In so far as there is a correlation between water content and ion permeability, then the Patent is not teaching anything new. At the very least, this is an indication that the teaching of the Patent in relation to ion permeability must be examined with some care, and it is one which is reinforced by Dr Port’s acceptance that he did not know of any material other than that used in the claimants’ FND product which has been discovered by measuring its ion permeability.

Next, it is apparent that the ion permeability thresholds of the claims are very different depending on whether the parameter is measured using the Ionoton or Ionoflux technique. To recap, the Ionoton threshold of claim 1 is 0.2 x 10^-6 cm²/sec, or 2 x 10^-7 cm²/sec whereas the Ionoflux threshold is 1.5 x 10^-6 mm²/min, or 2.5 x 10^-10 cm²/sec, a difference of three orders of magnitude. This, said Professor Freeman, is very surprising because both measure ion permeability and so one would expect the thresholds to be about the same. I agree. Moreover, the defendants contend the Ionoton values described in the Patent are impossibly high and the Ionoflux values are very low and easily, if not inevitably, exceeded. Neither therefore provides the skilled person with any practical assistance in finding lenses that will move on the eye or which are ophthalmically compatible. Needless to say, all these propositions are disputed by the claimants.

Dealing first with the Ionoton technique, Table E of the Patent sets out Ionoton values which are said to have been measured on the particular lenses listed in the left hand column of the table. This constitutes the only experimental evidence in the Patent of how the threshold Ionoton values relate to “on-eye movement.” I have considered this and its associated description in general terms at paragraphs [90] to [91] of this judgment in discussing the disclosure of the specification. In summary, the Patent specifies that “the lowest value of Ionoton Ion Permeability Coefficient for which a lens moves on the eye is 0.25x10^-3 cm²/sec,” and “the highest value of Ionoton Ion Permeability Coefficient for a lens which is bound on the eye is 0.008x10^-3 cm²/sec.” Professor Freeman explained, and I agree, that based on the description and the experimental evidence presented in Table E, the Ionoton Ion Permeability Coefficient threshold for on-eye movement of a contact lens must lie somewhere between 0.008x10^-3 cm²/sec and 0.25x10^-3 cm²/sec.

This deduction, whilst undoubtedly sound on the basis of the data presented, faces major problems. The first is that all the lenses in Table E for which on eye movement was recorded had Ionoton values in excess of the ion diffusion coefficient of sodium chloride in water, which is 2.1 x 10^-5 cm²/sec at 35°C. This is wholly improbable, as Professor Freeman explained. He is not aware of any literature source which reports an ion permeability value for a polymer which is higher than the transport rate of sodium chloride through water.

Second, the values in table E differ by orders of magnitude from ion permeability values given for contact lenses in the literature.

Third, the Ionoton permeability threshold of claim 1 of the Patent is 0.2x10^-6 cm²/sec. This is 40 times lower than 0.008x10^-3 cm²/sec, which is the lowest conceivable threshold value based on the data in Table E, and is 1,250 times lower than 0.25x10^-3 cm²/sec, which corresponds to the lowest Ionoton value for which there was on-eye movement, based on the data in Table E. Thus, as Professor Freeman put it, the claimed value is markedly lower than the on-eye movement threshold which the inventors have deduced from the experimental measurements which they have purported to carry out and is unsupported by any experimental evidence in the Patent. It was unclear to him, and it is unclear to me, from where the Ionoton Ion Permeability Coefficient threshold of claim 1 is derived. Indeed, Table E appears to show that a lens with an Ionoton permeability value above the claimed threshold did not move on the eye.

Dr Port initially expressed the opinion that Professor Freeman’s approach was fundamentally flawed as a matter of science. However, in cross examination he accepted that it was confusing that there was such a large difference between the threshold of claim 1 and the Ionoton values which are said to have been determined by the inventors experimentally and are set out in Table E. He also had no scientific explanation for these values being so high.

In contrast to the position in relation to the Ionoton permeability values, at least the claimed threshold for Ionoflux Ion Permeability Coefficient bears a relationship to the teaching in the Patent. The experimental data are set out in Table F. As I have explained, the Patent teaches that the lowest value of the Ionoflux Ion Permeability Coefficient for which a lens moved on the eye was 2.6 x 10^-6 mm²/min; and the highest value of the Ionoflux Ion Permeability Coefficient for which a lens bound to the eye was 1.5 x 10^-6 mm²/min. The Ionoflux limitation in claim 1 corresponds to that lower value of 1.5 x 10^-6 mm²/min, or 2.5 x 10^-10 cm²/sec.

Nevertheless, the difference between the claim thresholds for Ionoton and Ionoflux permeability is very striking. Professor Freeman described them as “vastly different”. In fact, the Ionoton threshold is 800 times greater than the Ionoflux threshold. But the position is yet worse when the reported experimental values are compared. The lowest Ionoflux value for which movement on the eye is reported is 2.6 x 10^-6 mm²/min or 4.33 x10^-10 cm²/sec. By contrast, the lowest Ionoton value for which movement on the eye is reported is 0.25 x10^-3 cm²/sec – a difference of more than 500,000 times and such that Professor Freeman considered the two values to be irreconcilable.

Indeed the Ionoflux threshold of all the claims is so low that, as Professor Freeman demonstrated in Figure 8 of his first report, the prior art contact lenses such as example 3 of Chang, example 4 of Lai and example VI of Keogh all soar above even the highest threshold of claim 17.

What then is the explanation for this discrepancy between the Ionoton and Ionoflux permeability values? No doubt it is attributable in part to the improbably high experimental values of Ionoton permeability to which I have referred. But it also seems tolerably clear the Ionoflux values are set far too low to provide any meaningful threshold. Professor Freeman expressed the belief in his reports and maintained under cross examination that these values are again the result of an error by the claimants. From a review of the claimants’ documents, he reached the conclusion that all of the Ionoflux coefficient values recited in the Patent, including those found in the claims, are an order of magnitude lower than the values obtained by the claimants prior to the filing of the Patent.

Professor Freeman’s starting point was an internal document disclosed by the claimants showing that the Ionoflux values reported in the Patent originated in the laboratory of Dr Dieter Lohmann, one of the inventors of the Patent, in Basel, Switzerland at some time before 30 November 1995.

Then in May 1996, Mr John Court wrote to Dr Angelika Domschke (both being further inventors of the Patent) in these terms:

Thereafter it seems that the creators of the Ionoton and Ionoflux techniques met the claimants’ patent attorneys to discuss the ion and water permeability measurements they had taken. It is thought that one of the subjects of discussion was another document disclosed by the claimants which contains details of the ion and water permeability measurements, including what became Table F of the Patent. This document suggests that Dr Domschke was given the job of checking the Ionoflux data and reporting any potential errors.

A further document disclosed by the claimants bearing the manuscript date May 1997 appears to be a further version of the meeting document with manuscript amendments which Professor Freeman believes were made by Dr Domschke. Certainly a note on its face suggests it originated from her. Hand-written amendments have been made to all the values apart from that of F-1. The exponents of examples F-2, F-3, F-4, F-5, F-6, F-10, F-11 and F-12 have all been amended to show values an order of magnitude greater than those indicated in Table F of the Patent. The values of examples F-8 and F-9 have also been amended to show values greater than those indicated, although not to the same extent. The exponent of example F-7 has been amended to show a value two orders of magnitude greater than that indicated in Table F of the Patent.

Professor Freeman expressed the opinion in his report that these amendments show that the claimants’ scientists believed the Ionoflux values ascribed to the examples in Table F of the Patent are incorrect and are not the values which the claimants actually measured for those materials.

Having taken the matter this far, Professor Freeman took upon himself the task of looking at other documents disclosed by the claimants to see if he could independently determine whether or not the Ionoflux values reported in the Patent are indeed ten times lower than the values the claimants actually obtained.

First, Professor Freeman ascertained that the claimants used code names to refer to the materials they created and he found a table which allowed him to cross reference those code names to the materials identified in Table F.

Professor Freeman then identified a report for the SEE3 project dated 30 June 1995 and apparently presented by Dr Domschke and Dr Hopken (another inventor of the Patent) which provides ion permeability data for all of the examples used in the Table F. But here an additional complexity emerged. The claimants often reported Ionoflux values not as absolute values but as values relative to a reference material. Specifically in the context of the SEE3 research programme, the claimants measured a “Diffusion Coefficient” for a specific batch of an “Alsacon” material as 3.14 x 10^-4 mm²/min and then reported Ionoflux Ion Diffusion Coefficients relative to this lens, which was set at 1.0. With this information available, it was possible for Professor Freeman to convert the relative Ionoflux values into the actual Ionoflux values measured by the claimants for those materials during the SEE3 project.

Professor Freeman duly carried out this exercise and then compared these Ionoflux values to those set out in Table F of the Patent. The results are presented in Table 5 to Professor Freeman’s first report. He concluded, fairly on the face of the data, that, with one exception, the values which he had derived and which he believes were actually obtained by the claimants are, within the uncertainty normally inherent in such measurements, ten times higher than the values reported in Table F of the Patent. In the case of example F-7 this is approximately one hundred times higher.

The final piece of the jigsaw is a publication by Dr Domschke, Dr Lynn Winterton and Dr Lohmann entitled Morphology requirements for on-eye mobility of soft oxygen permeable contact lenses, Proc. ACS Div. Polym. Mat. Sci. Eng 1997 Apr 13-17 (“the Domschke article”). Here the authors describe the work they have carried out, including permeation measurements and SANS experiments, which, they say, provides evidence for a bi-continuous phase morphology which has turned out to be “the key issue for on-eye mobility”.

Professor Freeman has determined from the data reported in Figure 2 of the Domschke article that an Ionoflux Ion Diffusion Coefficient of 3.14 x 10^-5 mm²/min represents the minimum threshold Ionoflux value between lenses that adhere on the eye and lenses that are mobile on the eye. As Professor Freeman also observed, the values set forth in the claims of the Patent are all significantly lower than this threshold value.

The claimants argue there are other possible explanations for these discrepancies. In this, they were supported by the evidence of Dr Nicolson who explained in his witness statement that, following Mr Court’s query, the subject matter experts on the SEE3 team were assembled to look into the question on at least two occasions and came to the conclusion that Mr Court was mistaken. Moreover, he says, during the SEE3 programme many hundreds of thousands of measurements were taken and documents produced. Each of the materials would have been tested numerous times. He reiterated this position in the course of his cross examination but frankly accepted that he was not personally involved in the measurement of Ionoflux values, that he was unable to point to anything in Professor Freeman’s analysis which was fundamentally wrong and that ultimately he was unable to assist one way or the other.

I feel a considerable unease at being asked to resolve this issue so long after the event and without a complete set of relevant documents. Nevertheless, Professor Freeman’s analysis is measured and thorough, his deductions appear to be sound and his ultimate conclusion is based upon a number of consistent pieces of evidence. Dr Nicolson, through no fault of his own, was not in a position to refute them and none of the other inventors gave evidence. I must decide this case on the materials before me and I have reached the conclusion that I must accept Professor Freeman’s analysis. I conclude that the Ionoflux Ion Permeability Coefficient values given for the F examples in the Patent are indeed ten times lower than the actual values Novartis obtained.

Despite the teaching to which I have referred, the claimants do not accept that any of the lenses and classes of lens described in the examples of the Patent satisfy the requirements of even claim 1, irrespective of their oxygen transmissibility and ion permeability values and irrespective of whether they show on-eye movement. As a matter of first impression, this seems a rather startling proposition, but it is one which the claimants advanced in meeting the allegation that the examples and classes of lenses described in Hopken and Domschke deprive the Patent of novelty. It will be recalled that in that connection I have accepted the claimants’ and the defendants’ common submission that it is simply not possible to tell whether any particular lens or class of lens does or does not satisfy the requirements of any of the claims of the Patent unless and until it is tested in the clinic.

The position is even worse in the case of a silicone hydrogel formulation which does not fall within the A to D families of materials. Prior to making the polymer it is not possible to predict whether it will meet the oxygen transmissibility and ion permeability thresholds of the claims although, for the reasons I have given, it is likely that at least the Ionoflux ion permeability threshold will be exceeded. However, even assuming these particular requirements are satisfied, the skilled person still does not know whether the lens will show on-eye movement or be ophthalmically compatible over a period of extended wear.

Dr Port expressed the following opinions in his first report. The Patent teaches a number of general principles and, in particular, the importance of ion permeability, the correlation between ion permeability and on-eye movement and the need to achieve a balance between that ion permeability and oxygen permeability in silicone hydrogel lenses. The examples disclosed in the Patent enable the skilled addressee to apply the teaching of the Patent to make contact lenses, which are not specifically disclosed, but which are within these general principles. In particular, the examples demonstrate how the properties of a lens will be affected if certain features of the composition of the lens are varied.

In cross examination, Dr Port accepted that he was not suggesting that any material which had an oxygen transmissibility and an ion permeability in excess of the thresholds set out in the claims would necessarily be ophthalmically compatible. He also observed there were no data in Table E or F which would enable a person skilled in the art to know if any of the lenses are suitable for extended wear over 24 hours or longer. At best, as I understood him, ion permeability is a predictor of on-eye movement, not least because polymers which vary possibly by quite small amounts may have quite large differences in ion permeability.

Dr Port was also asked to consider the position of a skilled team in 1995 which had decided to try to identify a suitable silicone hydrogel composition for use as a contact lens. He accepted the team would have been aware of a general method of making silicone hydrogel lenses and would have known of potential monomers with which to work. A reasonable approach would, he said, have been to consider the Kunzler and McGee graph (reproduced at [53] above) and seek to make a polymer composition with an oxygen permeability above 87 barrers and a water content of between 20% and 30%. I also understood him to accept that in all likelihood such a composition would have satisfied the ion permeability requirements of the claims, although ion permeability was not something the skilled person would have measured in the normal way. The upshot would have been a polymer composition and a lens which might or might not have satisfied the other requirements of the claims. If it did not, then the team would have had to look at all the information it had about wettability, ophthalmic compatibility and the like and decide where to proceed next. When asked what assistance the skilled team would derive from the Patent, he responded that it would help the skilled team to know what types of materials might give better movement on the eye because of their ion permeability.

There are, it seems to me, a number of problems with this evidence. The first is that the only general teaching which underpins all of the claims is that relating to ion permeability and oxygen transmissibility. Second, the Ionoflux ion permeability thresholds will, on this assumption, almost inevitably have been exceeded. Third, the only specific materials disclosed are those in families A to D, and these form the subject matter of claims 37 to 45. Even in respect of lenses made of these, the skilled person could not predict which would be ophthalmically compatible over a period of extended wear.

Dr Port’s overall position was, I think, summarised in this passage of his cross examination on day 3 from page 346-347:

Professor Koßmehl said in his first report that the Patent read to him like a textbook on extended wear contact lenses. It contains teaching on a number of aspects of the design, testing and performance of lenses and teaches a number of general and specific principles. In particular, the importance of ion permeability, the correlation between ion permeability and on-eye movement and the need to balance between that ion permeability and oxygen permeability with silicone hydrogel lenses. Moreover, he continued, the examples disclosed in the Patent enable the skilled addressee to apply the teaching of the Patent to make contact lenses which are not specifically disclosed in the Patent but which are within the general principles described. In particular, the examples demonstrate how the properties of a lens will be affected if certain features of the composition or manufacture of the lens are varied. In an annex to his report he elaborated upon these various points and as to the general teaching which he maintained the Patent contains.

In the course of his cross examination, Professor Koßmehl clarified that he was referring to the teaching of the Patent both in relation to ophthalmological properties and material properties necessary for extended wear. However, he rather qualified his opinion as to the value of the teaching, as the following extract from day 4 at page 482-483 makes clear:

A little later, he confirmed that it was fair to say that from the Patent, the skilled person was left with a large number of potential materials that might work.

Professor Valint considered in his first report how the person skilled in the art could set about making lenses which fall within the scope of claim 1. He observed that the skilled person could try to do this by following the examples in the Patent. However, he would not know which examples were suitable for extended wear, or wear at all, as the Patent contains no information as to patient comfort or lens toxicity, and, more importantly, it does not report any clinical data relating to the suitability of the lenses for extended wear (other than rudimentary results of on-eye movement). Given the Patent does not provide this information, the person skilled in the art would have to carry out an assessment of all the lenses exemplified in the Patent to identify those that are suitable for extended wear and it is unclear whether, at the end of the assessment, any would be found to be suitable for extended wear. At most, he continued, the Patent identifies four classes of silicone hydrogel materials which may be explored for useful extended wear contact lenses.

In the course of his cross examination I understood him to maintain that position. As far as he was concerned, the person skilled in the art well understood the need to balance the hydrophobic material in the formulation with the hydrophilic material in the formulation in order to get the requisite oxygen permeability and water content or water transport or saline transport, however it might be termed. Accordingly, in his view, the general teachings of the Patent were already understood. In his words (day 8 at 1031):

In my judgment it emerges from this evidence that the Patent does not enable the skilled person to predict whether any particular lens will satisfy the requirements of the claims without clinical testing. Moreover, and subject to the general teaching to which Professor Koßmehl referred, and which I consider immediately below, the Patent provides no practical assistance how to find potentially suitable polymer compositions beyond those described in families A to D.

As I have mentioned, Professor Koßmehl suggested that the Patent read to him like a textbook on extended wear contact lenses, so implying it contains a wealth of general teaching as to how to make an ophthalmically compatible lens suitable for extended wear. In the end, this came down to a few points, which I can address relatively shortly. But I should say at the outset that none is said by the Patent to be a unifying characteristic which serves to distinguish materials suitable for making extended wear lenses from those which are not.

The first is the use of macromers. This was a matter to which Professor Koßmehl attached some importance and they are described in connection with the specific families of materials disclosed in the Patent. However, I am quite satisfied on the evidence that although the particular macromers described in the Patent may be new, the concept of using macromers was well known and part of the common general knowledge. As Professor Valint put it, there were lots of silicone containing macromers in the literature. I discuss their importance in maintaining a microphase separation a little later in this judgment.

The second is the use of a cross linker at a relatively low level. I have addressed this in considering both the common general knowledge and the case of anticipation based upon Chang. Cross linkers were commonly used in connection with hydrogel materials for the purpose of introducing stability and there is nothing special about them.

Turning to manufacturing techniques, some importance was attached to UV curing and degassing and the exclusion of oxygen. I am satisfied that excluding oxygen was well known as a sensible technique to use, as was UV curing, and Professor Koßmehl accepted this was so.

Finally, there is surface treatment. Again I have addressed this in considering the common general knowledge. As I have explained, various surface treatment techniques did form part of the common general knowledge, including that described by Yasuda. But they were not generally used in connection with silicone hydrogels because their effectiveness for extended wear lenses had not been established, they tended to be short lived and, as Professor Koßmehl explained, the success of a particular type of surface treatment on a specific lens was no guarantee that the same treatment would have the same effect on any other. The Patent refers to the use of the Yasuda plasma technique but there is no teaching that the lenses to which it was applied were ophthalmically compatible over a period of extended wear. Moreover, the Patent does not suggest that surface treatment permits any prediction to be made about ophthalmic compatibility over a period of extended wear.

In summary, these teachings were either matters of common general knowledge which did not permit the production of an extended wear silicone hydrogel lens without invention or are not such as to provide any general teaching as to how such lenses can be made without undue effort.

The teaching in the Patent in relation to continuous phases or pathways, or even co-continuous phases or pathways was, however, said to be more fundamental and contrary to the perceived wisdom, and I have accepted that this was not obvious in light of the cited art or, I would add, the common general knowledge. But here the defendants again say the teaching is inadequate to permit the production of silicone hydrogel lenses which are ophthalmically compatible over a period of extended wear without undue effort.

The first and overriding objection is that the specification does not say which examples have continuous or co-continuous phases or pathways or whether lenses made from such materials are ophthalmically compatible over periods of extended wear. The matter is wholly unpredictable.

The defendants also contend that the Patent contains no or no sufficient teaching to enable a skilled person to make lenses having a plurality of co-continuous phases or pathways in any event. Before addressing this contention I must first relate a little of Professor Freeman’s substantially unchallenged evidence about the various morphologies that copolymers can adopt. If one considers a notional copolymer comprising red monomer units (A monomer) and blue monomer units (B monomer), they may adopt any of the morphologies illustrated in this figure which Professor Freeman produced:

As he explained, the figure illustrates that, as the fraction of A monomer units in the sample increases, the morphology goes from one in which there are spheres of A dispersed in a matrix of B (S), to one of cylinders of A dispersed matrix of B (C), to a bi-continuous micro phase (the so-called gyroid phase) (G) to a phase consisting of alternating layers of A and B (L), and then on through the same progression in geometric structures with A being the continuous component.

Professor Freeman continued that it is only in the case of bi-continuous morphologies that the A and B monomers reside in microdomains that are continuous in all three directions. By reference to published phase diagrams he illustrated that such bi-continuous morphologies only exist over a very narrow range of compositions and extents of thermodynamic incompatibility. In short, only some monomer combinations will have the necessary thermodynamic incompatibility to ever form bi-continuous morphologies and, even then, they will do so over only a narrow range of compositions. Further, even based on the current state of the art, it is extremely difficult, if not impossible, to design, a priori, polymer systems to achieve a certain morphology, particularly one, such as the gyroid phase, existing over such a narrow composition range.

The Patent itself provides very little assistance as to how bi-continuous morphologies or, in its terms, co-continuous phases or pathways extending continuously from one surface of the lens to the other, may be made. As I have mentioned, it teaches in paragraphs [0042] to [0044] that the ratios of oxyperm to ionoperm polymerizable materials may vary substantially. Paragraphs [0047] to [0049] describe how such co-continuous phases are believed to be advantageous but provides no assistance as to the conditions which will lead to their creation. For that, one has to turn to the description of the specific families of polymers. Hence paragraph [0173], upon which attention was focused, describes the C family of polymers which are formed by polymerizing particular macromers which contain free hydroxyl groups. These are said to function as an element which controls microphase separation between selected hydrophilic and hydrophobic components in a crosslinked end product. Finally, there is reference in paragraph [0343] to polymerization effected by UV irradiation after degassing.

Professor Freeman gave evidence in his first report, upon which he was not challenged, that it was inconceivable that bi-continuous microphase-separated materials could be produced over the wide composition ranges set out in paragraphs [0042] to [0044] of the Patent. He continued that paragraph [0046] of the Patent is misleading in suggesting that the specific weight or volume percentages of oxyperm and ionoperm polymerizable materials are not the most critical factors in preparing a good extended-wear ophthalmic lens. To the contrary, it was his opinion that the specific weight or volume percentages of the components in a polymer system are amongst the most critical factors in determining the eventual morphology of such a system.

On reviewing the Patent, Professor Freeman was unable to find any evidence that any of the specific examples contained continuous or co-continuous phases or pathways. Nor could he find any information to enable a skilled addressee to determine whether or not a polymer system of interest contained continuous or co-continuous phases or pathways. On this latter point he elaborated in cross examination that a range of standard techniques could and should be used to try and determine the morphology of a particular material but that it was very difficult to extrapolate from a tiny sample area, particularly if taken in only one plane.

Professor Valint expressed the opinion in his first report that the teaching of the Patent as to phase separation and co-continuous phases was vague and speculative. In the course of cross-examination he was taken to the various paragraphs of the Patent to which I have referred and also to aspects of the evidence of Professor Koßmehl and Professor Hamley. He considered that the suggestion that there was some relationship between the sizes of phases and the dimensions of the macromer was speculation but considered it plain that any microphase separation had to be less than the wavelength of light, that is to say 300 nanometres or less. It is also fair to say that he accepted the skilled person would know how to achieve a microphase separation of less than 300 nanometres. However, it is not clear to me quite what he meant by that answer and, in the context of his evidence as a whole, I am doubtful that he was intending to accept the skilled person would have known how to achieve the specific co-continuous phases or pathways called for by the claims.

Professor Hamley’s position as explained in his first report was that if a polymerization involving two monomers present in different proportions results in a phase separated structure and if the minority monomer is between about 25% and 40% of the combined weight then the resultant structure is likely to be one which consists of channels of one material within the other. These may be ordered, such as a set of cylinders running in the same direction, or random and chaotic, in which case the structure will be a co-continuous network. He also expressed the view that he was unable to say whether or not the Chang or Lai recreations or any of the examples in Hopken, Domschke or Keogh had co-continuous phases or pathways but, at the same time, suggested that the Patent taught clearly how the requisite phase separation was to be achieved. In particular, he pointed to the weight ratios in paragraph [0042], the teaching in relation to the macromer used to make the polymers of family C in paragraph [0173] and the polymerization conditions taught in paragraph [0343].

It is apparent that the opinions Professor Hamley expressed in his report are rather different to those of Professor Freeman. Yet in the course of cross examination I understood Professor Hamley generally to agree with the opinions of Professor Freeman. I also understood him to soften his opinion as to the likelihood that a co-continuous phase structure would result from the use of the rather wide monomer ratios to which he had referred in his report and to adopt a rather more consistent position in relation to the Patent and the prior art.

Professor Koßmehl focused in his first report on the teaching in paragraph [0173] of the Patent that macromers enable phase separation by means of a specific molecular architecture and he elaborated upon that in his third report by explaining that the skilled person would design or choose such a macromer by controlling such matters as the nature and number of hydrophobic and hydrophilic groups to provide appropriate hydrophobic and hydrophilic regions of the macromer, the nature and number of functionalised groups that can form polymer links, cross-links or hydrogen bonds with other molecules and the position of each of these groups with respect to the others, the distances between them and the overall size of the macromer. Professor Koßmehl was cross-examined upon this evidence and this left me with the distinct impression that it would not be easy to design co-polymer systems which would produce co-continuous phases or pathways and it would involve a good deal of trial and error.

I have to say that of all this evidence I have found that of Professor Freeman to be the most cogent and consistent. I am satisfied that the Patent gives very little practical assistance to the skilled person seeking to make a lens falling within the scope of claims 8 or 11 beyond the teaching in relation to families of materials A to D and even here there is no disclosure of which specific examples comprise the co-continuous phases required by the claims. Insofar as the Patent does contain teaching as to the specific weight or volume percentages of the components of a potential polymer system, it is misleading for two reasons. First, I am satisfied in the light of Professor Freeman’s evidence that it is highly unlikely that co-continuous microphase-separated materials could be produced over the wide composition ranges disclosed in paragraphs [0042] to [0044] of the Patent. Further, the Patent suggests that the specific weight or volume percentages of oxyperm and ionoperm polymerizable materials are not the most critical factors to consider when, in fact, they are amongst the most critical factors in determining the eventual morphology of the polymer system. Overall, I am satisfied that the skilled person would be faced with a research programme in seeking to implement the teaching of the Patent to produce any lenses other than those the subject of the specific examples disclosed. But as to those, the skilled person is not told which, if any, exhibit continuous or co-continuous phases or pathways.

Moreover, and as will be seen when I turn to consider infringement, it requires a considerable investigation to determine whether a copolymer of the kind in issue comprises co-continuous phases or pathways.

I have largely addressed these in considering other aspects of the teaching. But to summarise, they remain subject to the overriding criticisms that first, the Patent does not teach which materials within the specific families and examples described are suitable for the production of ophthalmically compatible extended wear lenses; and second, the Patent does not permit the skilled person to make a prediction that any lens is likely to be ophthalmically compatible over a period of extended wear. I am satisfied that both of these criticisms are sound.

Conducting clinical trials of a new lens is by no means a straightforward matter. Dr Brennan gave evidence in his third report that a trial of two new lenses over a 24 hour period with up to thirty subjects per lens would cost a great deal of money. In cross examination he put it at somewhere in the region of 100,000-140,000 US dollars. A trial for that number of subjects for an extended period of up to 30 days would obviously be rather more. Dr Port considered that clinical trials were an expensive process although he frankly accepted that he had not costed such trials for some time.

I draw the following general conclusions from the foregoing.

First, the Ionoton Ion Permeability Coefficient values taught by the Patent and set by the claims are extremely confusing and of little or no practical assistance to the skilled person seeking to make an ophthalmically compatible lens suitable for extended wear.

Second, the threshold Ionoflux Ion Permeability Coefficient values taught by the Patent and set by the claims are so low that that they will easily, if not inevitably, be satisfied. As such, they provide little or no practical assistance to the skilled person seeking to make an ophthalmically compatible lens suitable for extended wear.

Third, the Patent does not enable the skilled person to make any prediction as to whether a lens is ophthalmically compatible over a period of extended wear without clinical testing; nor can he make any prediction as to whether a particular silicone hydrogel formulation is suitable for making such a lens.

Fourth, the skilled person cannot even make any prediction as to whether any and, if so which, of the lenses described in the Patent are ophthalmically compatible over a period of extended wear; nor can he make a prediction as to whether any, and if so which, of the formulations described in the Patent are suitable for making such a lens.

Fifth, the Patent does not teach which, if any, of the lenses or formulations described in the Patent have continuous or co-continuous phases or pathways and provides no or no adequate teaching as to how to produce lenses having such co-continuous phases or pathways in any event.

Sixth, it follows there is no or no adequate teaching in the Patent of any unifying characteristic or principle of general application which would enable the skilled person to predict which silicone hydrogel formulations are likely to be useful for producing an ophthalmically compatible lens suitable for extended wear. The teaching is not such that success may be achieved and ensured.

Seventh, it would involve a considerable amount of work and great expense to test any reasonable number of lenses on a reasonable number of subjects to ascertain whether they are ophthalmically compatible over a period of extended wear.

Eighth, in the light of the foregoing and the absence of such a unifying characteristic or principle of general application, it would involve a research programme to identify silicone hydrogel formulations which are useful for producing an ophthalmically compatible lens suitable for extended wear. I have made a like finding in relation to the allegation that it was obvious how to produce such a formulation in the light of the common general knowledge and the cited art.

In my judgment a finding that the Patent is insufficient is therefore inevitable.

For the purposes of this litigation only, and so far as claim 1 is concerned, the defendants accept that the Oasys lenses:

are suited to extended periods of wear and thus

have ophthalmically compatible inner and outer surfaces;

comprise at least one oxyperm and one ionoperm polymerizable material; and

have the necessary ion permeability.

The only point in issue is therefore oxygen permeability. The defendants say that if oxygen permeability is to be determined by the coulometric method then the imperfections in the claimants’ experiments are such that no reliance can be placed on the results. In the end, the defendants relied upon only the one point, namely the failure of the claimants to calibrate the Dk1000 machine. This is an issue which I have addressed in considering the Lai recreations. For the reasons which I have given in that context, I am satisfied there was no need to calibrate the Dk1000 machine absent some evidence that it was not working properly or efficiently. There was no such evidence in this case. I am therefore satisfied that the oxygen permeability results obtained by the claimants do establish that the Oasys lens falls in the scope of claim 1. I am confirmed in this view by the evidence of Professor Valint that the Oasys lens has been measured to have a Dk of about 100 barrers.

These claims gave rise to a substantial dispute between the parties as to whether or not the polymeric material of the Oasys lens comprises a plurality of co-continuous phases, at least one being an oxyperm phase and at least one other being an ionoperm phase, which phases extend continuously from the inner surface to the outer surface of the lens.

The claimants relied upon a series of experiments using a variety of techniques, some of which (TEM, FEGSTEM, EDX, SAXS, SANS and AFM) I have already referred to in my assessment of the witnesses.

The first is Differential Scanning Calorimetry (“DSC”). This is a standard technique used to detect the glass transition temperature of a polymer material, that is to say the temperature at which it undergoes a transition from a soft or rubbery state to a rigid or glassy state. Copolymer materials with two separated phases will exhibit two separate glass transition temperatures, one characteristic of each phase. It was, however, common ground that DSC does not teach anything about polymer morphology. This requires the deployment of other techniques.

One such is the TEM - Transmission Electron Microscopy - technique to which I have referred and in which a beam of electrons is used to illuminate a sample. In simple terms, an electron source is placed on one side of the sample and a film used to record the image is placed on the other. The resultant image represents the extent to which areas of the sample allow the transmission of electrons. In a phase separated copolymer, the different phases will allow different proportions of electrons through them, providing information about the size and shape of the phase domains.

FEGSTEM - Field Emission Gun Scanning Transmission Electron Microscopy - is a related technique in which an extremely fine electron-beam probe is scanned across the sample in a rectangular pattern. Detectors collect the electrons that pass from the probe through a given point on the sample. This technique has the benefit that it does not use a lens to operate on the signal carrying electrons after they have passed through the sample and it can provide a high degree of resolution.

Another is EDX - Energy Dispersive X-Ray analysis – which can be used, as in this case, together with FEGSTEM. It involves a sample being bombarded with a focused beam of electrons, which are then absorbed by the sample and induce the emission of X-Rays. The X-Rays are characteristic of the elements present in the sample, and a comparison of the X-Rays emitted from a particular sample with a known X-Ray spectrum for each element yields an elemental analysis of the sample. A combination of FEGSTEM and EDX can provide information about the morphology of a sample, and also permit the characterisation of the elemental composition of its different domains.

As Professor Hamley accepted, the techniques of TEM and FEGSTEM are carried out on thin slices of material and so do not themselves directly provide information about three dimensional character of its morphology. So it is helpful to study sections of the material taken in different planes.

For this purpose, AFM - Atomic Force Microscopy (“AFM”) can be used. This involves the measurement of the interaction between the tip of a very fine probe and the surface of the sample. Professor Hamley offered the analogy of a gramophone in which the tip of the probe acts in a similar way to the gramophone stylus and produces a signal indicating the topology of the sample, and of the relative hardness across its surface.

I should also say a further word about the two techniques SAXS - Small Angle X-Ray Scattering - and SANS - Small Angle Neutron Scattering. As I have mentioned, the claimants’ notice of experiments suggested that they would be relying on experiments using SAXS to establish infringement. But these were abandoned, without explanation, at about the time that Professor Hamley was instructed. Interestingly, the claimants used SANS when seeking to characterise the morphology of the Domschke materials. As Professor Hamley explained, these techniques have the benefit that they provide information about the morphology of a polymer system in its hydrated state. By contrast, the samples used in the TEM and in FEGSTEM experiments were dried and subjected to a vacuum. Professor Freeman explained, and I accept, that there is at least some doubt as to whether results of TEM, FEGSTEM, DSC and AFM experiments on dehydrated lenses can provide information representative of the morphology of the hydrated lenses.

As I say, the approach taken by the claimants was to carry out TEM, FEGSTEM, EDX, AFM and DSC experiments of the kind I have described. The samples for TEM and FEGSTEM were taken as slices normal to the top surface of the lens, whereas those for AFM were taken parallel to the top surface. Professor Hamley thought this was important and supported the conclusion that that the Oasys lens has a phase-separated morphology running throughout the material with co-continuous phases running from one surface of the lens to the other.

Before turning to the substance of the experiments, there is one other preliminary matter with which I must deal. The claimants sought not only to rely upon the repeats of their experiments, but also, on occasion, upon their original notice of experiments. They called no expert who performed or witnessed the experiments the subject of the notice and so the defendants had no opportunity to explore the circumstances in which those original experiments took place, how they were performed and whether the results reported in the notice were in fact obtained, and if they were, whether they were selected from other and less favourable results. By contrast, in the case of the repeats, I heard evidence from those who performed the experiments and those who witnessed them. In the circumstances I consider it appropriate to focus on the results obtained in the repeats where any controversy arises.

I begin with the DSC results which show the Oasys lens consists of two phases. Based upon the glass transition temperature measurements obtained, Professor Hamley concluded that one phase consists essentially of oxyperm polymer and the other consists essentially of ionoperm polymer. Subject, perhaps, to a question, of degree, I do not understand that conclusion to be challenged by the defendants. But it is important to appreciate its limitations. As Professor Hamley accepted in the course of cross examination, DSC teaches nothing about the size of the respective phases other than that they are bigger than a few molecules in size. Further, and most significantly, the experts were all agreed that DSC results reveal nothing about morphology.

That brings me to TEM and FEGSTEM. Taking first the TEM images, attention focused on those exhibited by Professor Hamley to his first report. He observed, and I agree, that the TEM images of the Oasys lens do have a mottled appearance. He concluded that the darker domains have higher average atomic mass and so inferred they contain siloxane-based materials whereas the lighter domains have a lower average atomic mass and so contain hydrophilic ionoperm materials, which are composed principally of carbon, nitrogen and oxygen atoms. He thought the images established a substantially phase separated morphology and were consistent with a co-continuous structure of oxyperm and ionoperm phases or pathways. He maintained his view under cross examination. Dr Bradley, on the other hand, was rather more cautious. He thought the images were consistent with three possibilities, namely a variation in composition, density or thickness. He also drew attention to the fact that the images show no well-defined structures or contrast variation, and, by way of comparison, produced an image of another copolymer system to demonstrate how TEM can provide evidence of quite clearly phase separated domains where one phase is silicon rich and the other silicon poor.

The FEGSTEM experiments were carried out on a separate occasion in February of this year. The contrast of FEGSTEM is the opposite of that observed in conventional TEM because FEGSTEM produces dark field images whereas those of TEM are bright field. So in this case the lighter domains represent material of higher average atomic mass whereas the darker domains represent material of lower average atomic mass. Once again, Professor Hamley exhibited, in this case to his third report, the images which he considered to be particularly relevant. They have much the same general appearance as the TEM images. Professor Hamley therefore again inferred the lighter domains represent oxyperm material and the darker domains represent ionoperm material.

Professor Hamley also exhibited two sets of EDX line scan data derived from the same samples. These appear to show domains which are silicon rich and domains which are silicon poor and, perhaps more importantly, a visual inspection suggests a correlation between the lighter domains in the FEGSTEM images and a higher silicon count in the EDX line scan. Professor Hamley explained this is confirmed by cross correlation data which he has also exhibited. These data demonstrate the correlation is strong and is not caused by noise.

I am satisfied that Professor Hamley’s conclusions are sound, so far as they go. But I am not persuaded that they lead to the conclusion that the light and dark regions in the FEGSTEM images correspond to ionoperm and oxyperm material respectively. The FEGSTEM and EDX data are also consistent with the lighter and regions simply representing material of greater density. Indeed, there are two further pieces of evidence which suggest this alternative explanation may be correct.

First, Dr Bradley exhibited various other EDX line scans to his third report which reveal no regions of the Oasys lens sections which are essentially silicon free. Professor Hamley accepted this was so but suggested that a possible explanation was the presence of irregular channels with dark domains not necessarily extending perfectly orthogonal to the plane of the image. So, he continued, they might twist off to one side or another, rather like rabbit holes, such that a view of a particular region from above might include a domain of one material on top of a domain of the other.

The second concerns equivalent EDX line scan data for carbon. Professor Hamley expressed the view that, unlike silicon, the carbon content of oxyperm and ionoperm material should be broadly similar. Accordingly, if the material contains separate domains of oxyperm and ionoperm materials, one would expect the EDX silicon line scan to vary from one domain to another but the carbon line scan to remain constant. However, at least some of the EDX line scan data exhibited by Dr Bradley shows that the level of carbon in fact tracks the level of silicon. Professor Hamley accepted that these results are inconsistent with his hypothesis (although they would be consistent with a change in density) but suggested they might be attributable to a failure to accumulate enough data.

Turning to the AFM experiments, Professor Hamley concluded the phase images obtained from the Oasys lens show a phase separated morphology on a length scale similar to that observed with TEM and FEGSTEM. In these images, the lighter regions represent harder material which Professor Hamley associated with the dried ionoperm phase material. The darker regions represent softer material which Professor Hamley associated with the silicon based oxyperm phase material. In his view, the presence of this morphology at the two surfaces of the lens indicated that the co-continuous ionoperm and oxyperm phases were also present on the lens surfaces. This, together with the electron microscopy results were, in his opinion, indicative of continuity of the ionoperm and oxyperm phase domains from one lens surface, through the bulk lens material, to the other lens surface. I understood Professor Hamley to maintain his position under cross examination.

Professor Freeman criticised Professor Hamley’s approach as being built upon an assumption, which in his view was not correct, that the Oasys lens material contained separate silicon-containing oxyperm and silicon-free ionoperm phases. As he pointed out, AFM does not provide information on composition and therefore, in reaching his conclusion, Professor Hamley relied on his prior assumption both as to the presence of separate phases in the Oasys lenses and the composition of those phases.

In my judgment, this criticism has some substance. Professor Freeman maintained in the course of his cross examination, and I accept, that in order to draw a fair and objective conclusion the first step must be to consider separately the data derived using each experimental technique to see what conclusions can properly be drawn. Then, at the end of the day, the entire picture should be put together.

Professor Freeman also drew particular attention to the images obtained during the witnessed experiments and compared images taken from the inner surface of the Oasys lens with equivalent images taken from an Acuvue lens. He also compared these images with an AFM image taken from the core of an Oasys lens. I have to say I found this comparison rather striking. As Professor Freeman elaborated, the AFM image of the Acuvue lens shows light and dark regions of a not dissimilar nature to those apparent in the image of the Oasys lens but, as everybody accepted, the material of the Acuvue lens is not phase separated. It also follows, said Professor Freeman, and I accept, that the presence of light and dark regions in the images of the Oasys and Acuvue lenses cannot simply be ascribed to the existence of phase separation. I am also satisfied that the AFM image of the core of an Oasys lens appears rather different to the image of its surface. Overall I prefer Professor Freeman’s conclusion that one cannot draw definite conclusions from these images and they are consistent with the presence of regions of amorphous polymer.

Stepping back and looking at the experiments as a whole, as I must, the DSC experiment establishes that there is phase separation in the Oasys lens but provides no evidence of polymer morphology. The TEM and FEGSTEM images are all taken in a plane orthogonal to the surface of the lens and reveal different domains which may represent materials of different composition or density. The EDX data are somewhat ambiguous. The silicon line traces suggest the domains shown in the FEGSTEM experiments have different silicon content. But they also suggest that none of the domains are silicon free and so it cannot be said they are composed essentially only of ionoperm polymer, subject to an explanation of the rabbit hole kind. Moreover, some of the carbon line trace data appears to track the silicon line trace data – a result inconsistent with the theory of co-continuous phases, but consistent with the theory that the domains represent domains of different density. Finally, the AFM results are potentially valuable in providing information about the morphology of the sample in a different plane. But the AFM results are, at best, ambiguous.

All in all, I am not persuaded that the claimants have established infringement of these claims.

This claim requires a surface which is more hydrophilic than the core. The claimants sought to prove infringement of this claim by an experiment involving what is known as the Sessile Drop Contact Angle Test. This involves placing a droplet of water on the surface to be tested, capturing an image of the droplet and then measuring the angle between the surface and the edge of the droplet adjacent to that surface (the contact angle). The smaller the contact angle, the more hydrophilic the surface.

The claimants accordingly served a notice of experiments showing the Oasys lens exhibits a much smaller contact angle on its outer surface than on a core surface exposed by shaving off the top of the lens with a blade. Measurements were taken of the lens in a hydrated and dry state.

The defendants do not dispute the test is appropriate, nor the results obtained. Indeed they did not request a repeat of the experiment. Instead, they say that the values obtained for the core should be disregarded because the lens was cut using a blade. In support of this position Professor Valint gave evidence that the roughness of the surface can affect contact angle measurements and that the manner in which the surface is prepared is critical.

I have come to the conclusion in the light of the evidence as a whole that the claimants have established the Oasys lens falls in the scope of claim 24. Dr Port said in the course of his cross examination that he could not rule out the possibility that the method of cutting did have some effect but maintained that, if done carefully with a razor blade, it would not have much of an impact on the results. He considered the results obtained did fairly reflect the reality and, the defendants not having requested a repeat or performed any experiments of their own, I accept his evidence. I am confirmed in this conclusion by the defendants’ own advertising material which makes a particular feature of the hydrophilicity of the lens surface.

I conclude the claimants have established the Oasys lens falls in the scope of claims 1 and 24, but not claims 8 or 11.

The parties did not address me specifically on the other claims alleged to be infringed and in the light of my findings it is not necessary to deal with them individually.

The Patent is invalid for insufficiency. The attacks of lack of novelty and obviousness have failed. The claimants have established that the Oasys lens falls in the scope of claims 1 and 24, but not claims 8 or 11. I will hear argument as to the form of order if it cannot be agreed.