CA2036782A1 - Ophthalmic lenses based on amorphous fluoropolymers - Google Patents
Ophthalmic lenses based on amorphous fluoropolymersInfo
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- CA2036782A1 CA2036782A1 CA002036782A CA2036782A CA2036782A1 CA 2036782 A1 CA2036782 A1 CA 2036782A1 CA 002036782 A CA002036782 A CA 002036782A CA 2036782 A CA2036782 A CA 2036782A CA 2036782 A1 CA2036782 A1 CA 2036782A1
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- Prior art keywords
- ophthalmic lens
- units
- formula
- lens according
- copolymer
- Prior art date
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- G—PHYSICS
- G02—OPTICS
- G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
- G02C7/00—Optical parts
- G02C7/02—Lenses; Lens systems ; Methods of designing lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G02B1/041—Lenses
- G02B1/043—Contact lenses
Abstract
V-17969/1+2/=/TIT 12 Ophthalmic lenses based on amorphous fluoropolymers Abstract The invention relates to ophthalmic lenses, such as contact lenses or intraocular lenses, which essentially consist of an amorphous copolymer which comprises units of theformula I
(I) and units of the formula II
-CF2-CF2- (II) in which a and b independently of one another are zero, one or two, and in which R1 and R2 independently of one another are perfluorinated lower alkyl.
They have a combination of high hardness and oxygen permeability. They moreover have such a high glass transition point that they can be autoclaved. Their crystallinity and their refractive index are furthermore decidedly low.
(I) and units of the formula II
-CF2-CF2- (II) in which a and b independently of one another are zero, one or two, and in which R1 and R2 independently of one another are perfluorinated lower alkyl.
They have a combination of high hardness and oxygen permeability. They moreover have such a high glass transition point that they can be autoclaved. Their crystallinity and their refractive index are furthermore decidedly low.
Description
V-17969/1+2/=/TIT 12 Ophthalmic lenses based on amorphous fluoropolymers The invention relates to ophthalmic lenses, such as contact lenses and intraocular lenses, which essentially consist of amorphous fluoropolymers, to processes for the production of such lenses, to such processes, including subsequent surface treatrnents, and to the use of corresponding amorphous fluoropolymers for the production of contact lenses and intra-ocular lenses.
Amorphous fluoropolymers are further developments of polytetrafluoroethylene which has already been known for some decades. Amorphous fluoropolymers are disclosed, for ex-ample, in EP-A-073 087 or EP-A-l l l 343. According to EP-A-073 087, these are copoly-mers which are obtained from tetrafluoroethylene and perfluoro-2,2-dimethyl-1,3-dioxole, and possibly a third monomer, for example propylene, isobutylene or ethylene. Polytetra-fluoroethylene compositions which are prepared, for example, using certain amounts of the abovementioned dioxole or derivatives thereof are disc losed in EP-A- 111 343.
Since 1989, such amorphous fluoropolymers have also been commercially available.Thus, Dupont markets the products Teflon AF 1600 and 2400, in which "AF" means "Amorphous Fluoropolymer". These products are copolymers of tetr~fluoroethylene and perfluoro-2,2-dimethyl-1,3-dioxole.
According to EP-A-073 087, the amorphous copolymers disclosed therein are suitable for uses such as windows for chemical reactions, specifically in processes in which hydrogen fluoride is used or forms. The amorphous copolymers disclosed in EP-A-111 343 are described as being useful in making molded parts, specifically in instances where smooth surfaces are important, such as ball valve seats. The polymers Teflon AF 160Q and 2400 ;
marketed by Dupont are described in the product description accompanying them as being suitable for coatings or coverings for optical devices, including those which are used within wide temperature ranges and in a chemically aggressive environment. Elsewhere in the advertising material it states that Teflon AF is an ideal candidate for optical devices for medicine, military, aerospace and industry.
It has now been found that, surprisingly, ophthalmic lenses having exceptionally advanta-geous properties can be produced from amorphous fluoropolymers. Contact lenses or intraocular lenses according to the invention thus have a combination of high hardness and oxygen perrneability. They moreover have such a high glass transition point that they can be autoclaved. In addition, their crystallinity and refractive index are decidedly low. The refractive index can be, for example, made close to the refractive index of the lacrimal film, so that an optimum course of ray results. The refrac~ive index can be adjusted, for example, by varying the nature and amount of comonomers used. According to the in-vention, for example, toric contact lenses of low refractive index can thus also be pro-duced. If intraocular lenses according to the invention are used, fewer complications in respect of secondary cataract formation are expected in view of the material properties.
If materials having a refractive index of between 1.47 and 1.52 are used and a contact lens geometry which is toric on the inside is used, an artificial residual astigmatism arises between the lacrimal fluid and lens material because of the differences in refractive index, and this then has to be corrected on the front curve of the lens with the aid of a toric surface. The production and fitting of such lenses is very expensive.
On the other hand, if a lens material according to the invention having a refractive index of between 1.31 and 1.33 is used to deal with relatively highly astigmatic corneas, there is either no jump or only a very small jump in refractive index. Correction of the undesirable artificial residual astigmatism is thus unnecessary. This makes the lenses and their fitting considerably cheaper.
If materials of relatively low refractive index are used, there is usually a non-optimal distribution of the overall thickness. In extreme cases, the relatively steep lenticular rise leads to incompatibility. However, this effect can be avoided by using a corneoscleral design. A corneoscleral design having diameters of between 11.5 and 13.5 mm not only leads to a general improvement in compatibility because of the large diameter, but allows a balanced division of the lens between the corneoscleral haptic and the optically active surface. The corneoscleral haptic can be designed perfectly here in respect of compability without taking into consideration the optical requirements. The unfavourable distribution of overall thickness which occurs al: the low refractive index has an effect only in the optically active part and in no way affects the compatibility.
Another great advanlage of the material according to the invention lies in the high oxygen P r 3 ~
permeability, which means that it is particularly predestined for corneoscleral design. In-corporating measures for adequate rinsing behind the contact lens (turbo effect, microla-crimation and the like), it is possible to use the material in combination with the corneo-scleral design under particularly adverse circumstances, and moreover the material is suitable for wearing for several days.
The ophthalmic lenses according to the invention therefore combine a range of favourable parameters such as have not been described for contact lenses or intraocular lenses to date.
The invention therefore relates to ophthalmic lenses consisting essentially of an amorphous copolymer which comprises units of the formula I
--fF fF
O O
(C~a ~CF2)b (I) R/ \R
and units of the formula II
-CF2-CF2- (II) in which a and b independently of one another are zero, one or two, and in which R1 and R2 independently of one another are perfluorinated lower alkyl.
Perfluorinated lower alkyl contains up to 7 carbon atoms, in particular up to 4 carbon atoms, and is, for example, perfluorinated methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl or tert-butyl, preferably trifluoromethyl. -The units of the formula I and of the formula II can be present as blocks or can alternate randomly. The content of units of the forrnula I is preferably at least 10 mol per cent and is particularly 10 to 80 mol %.
The sum of the indices a and b in a unit of the formula I is preferably not greater than two.
The indices a and b are particularly preferably zero. In a specific embodiment, a and b are each zero and Rl and R2 in each case are perfluorinated C~-C4aLkyl, in particular tri-fluoromethyl. According to this embodiment, further comonomers can be dispensed with and the molar Tatio of units of the formula I to units of the forrnula II is in the range from 30:70 to 90:10, preferably in a range from 50:50 to 85: lS. Particularly preferred ratios of units of the formula I to those of the forrnula II are about 50:50 and about ~0:20 ("about"
in this connection is to be understood as meaning a deviation of not more than +10 %).
In addition to the units of the formula I and II, the copolymer can comprise other units in amounts of up to 40 mol % of the copolymer. These units can also be in the form of blocks or can alternate randomly with one another or with units of the formula I and II. Suitable units here are those of the formula III
1R3 (III) in which R3 is a perfluorinated alkyl radical of the formula CnF2n+l, in which n is 1 to 4, or in which R3 is a perfluorinated cycloalkyl radical of the formula CmF2m " in which m is 5 to 8, and/or those of the formula IV
-CX-CX -I I (IV) in which X and X' independently of one another are hydrogen or fluorine and R4 and Rs independently of one another are hydrogen, fluorine, lower alkyl or perfluorinated lower alkyl, excluding those units of the forrnula IV in which X, X', R4 and R5 are fluorine.
A perfluorinated alkyl radical of the forrnula CnF2n+l is, for example, perfluoromethyl, -ethyl or -propyl. A perfluorinated cycloalkyl radical of the formula CmF2m, is, for example, perfluorocyclohexyl or -cyclopentyl. Perfluorinated lower alkyl R4 or R5 is as defined above for Rl/R2. Lower alkyl R4 or Rs has up to 7, preferably up to 4, carbon atoms and is, in particular, methyl, ethyl, propyl or butyl.
The units of the formula IV comprise perfluorinated, partly fluorinated and fluorine-free units. Perfluorinated and fluorine-free units of the formula IV are preferred. The former are those, for example, in which X, X' and Rs are fluorine and R4 is perfluorinated lower S
alkyl. The latter are, for example, those in which X, X' and Rs are hydrogen and R4 is lower alkyl. Partly fluorinated units of the forrnula IV are, for example, those in which X, X' and Rs are hydrogen and R4 is perfluorinated lower aLlcyl.
Units of the formula I and II together with units of the formula III or together with units of the formula IV, for example, can occur in the copolymer of which the ophthalmic lenses according to the invention consist. Combinations of units of the formula I and II with units of the formulae III and IV are also possible.
The total amount of units of the forrnula III and IV, where these are present, is preferably up to 30 mol % of the copolymer, and particularly preferably up to 20 mol % of the copo-lymer. An embodiment of Ihe invention which is likewise preferred comprises, however, ophthalmic lenses of copolymers which consist to the extent of at least 90 mol %, more appropriately to the extent of at least 95 mol %, and particularly preferably exclusively, of units of the formula I and II. Ophthalmic lenses, specif1cally contact lenses, of the com-mercially available materials Teflon AF 1600 and Teflon A~ 2400 or mixtures thereof are most preferred. According to the knowledge of the inventors, these materials are copoly-mers such as are used according to claim 4, containing ~0 mol % and 80-90 mol % respec-tively of units of the fonnula I.
The monomers which are required for the preparation of the copolymers are known or can be prepared in a manner wbich is known per se. For example, monomers which provide units of the formula I in the copolymer are described in US Patent 3 978 030. The mono-mers which provide units of the formula II or IV in the copolymer are all commercially obtainable. The monomers which provide units of the formula III in the copolymer are described in standard works, cf., for example, Houben-Weyl, supplement E~0.
The preparation of amorphous copolymers which are used for the preparation of the contact lenses according to the invention is described, for example, in EP-A-073 087 and EP-A-111 343.
In view of the fact that the copolymers used according to the invention can be processed as thermoplastics, there is an abundance of possibilities of producing contact lenses from them. The amorphous copolymers in the form of, for example, granules, powders or films can in each case be used here as starting materials.
The lenses according to the invention can thus be produced by processes which are known per se, such as static mould casting, spin casting, pressing, deep-drawing, thermoforming, lathe cutting or laser machining.
. .
These process steps are known per se and therefore do not require more detailed explana-tion for the expert. However, liquid monomers or monomer mixtures or solutions of solid monomers which polymerise only in the course of the production of the lens or blank, are usually used as starting materials for the production of contact lenses. The peculiarity of the preparation processes according to the invention is that finished copolymers which are thermoplastic are used as the starting materials. These materials therefore also allow routes to be followed which are not usually taken for the production of contact lenses, alongside the classical contact lens production processes, such as lathe cutting of a button, spin casting or static mould casting in individual moulds, which, in some cases in modirled form, can also be used with the present invention.
Static mould casting can be carried out, for example, by injection moulding. For this, the amorphous copolymer is melted at temperatures of 160-240C, preferably 210-220C, and is injected into the mould by means of an injection moulding machine. If moulds with a base curve and front curve are used, contact lenses can be produced directly. It is further-more possible to produce contact lenses by casting, by in~oducing a solution of the amor-phous copolymer in an organic solvent into a mould with a concave curve and convex curve, after which the solvent is allowed to evaporate. Suitable solvents in this and the fol-lowing processes are, for example, perfluorinated ethers or perfluorinated hydrocarbons.
Spin casting can also be used according to the invention, by introducing a solution of the amorphous copolymer into a mould for spin casting, after which the mould is rotated.
During this operation, the solvent evaporates. The finished contact lens, the dimensions of which can be controlled by the dimensions of the mould, the speed of rotation and the viscosity of the solution introduced, remains in the mould.
Pressing is carried out according to the invention, for example, by melting the amorphous copolymer and pressing it in a mould or by compression moulding a film of the amorphous copolymer. A film of the amorphous copolymer can be produced in a manner which is known per se, for example by extrusion, by blowing or by casting a solution of the amorphous copolymer.
A contact lens can also be produced in a manner which is known per se by deep-drawing or thermoforming from a film produced, for example, as men~ioned above.
Lathe cutting is also suitable as the last process step for the production of contact lenses according to the invention. This always applies i~, for example, a blank obtainable by one s)f the abovementioned processes requires further working. Lathe cutting is to be under-stood as meaning conventional machining of e.g. contact lens buttons. Corresponding blanks can be produced, for example, by injection moulding, extrusion of round rods and division thereof, casting from a solution or casting of a melt. The term contact lens blank in this connection includes buttons or semi-mould products, for example base curve blanks. Typical blanks have thicknesses of 4 or 6 mm and diameters of 10 to 17, for example 12 or 14 mm.
Laser machining can also be used according to the invention, blanks or contact lenses produced by one of the other processes being used as the starting material where they still require additional fineworking of their surface.
Intraocular lenses according to the invention can also be produced in a manner which is known per se, for example by lathe cutling processes or by pressing from powder,granules or film. Different haptics can be employed for intraocular lenses according to the invention. The haptic here can be intregrated into the mould shape, or subsequently shaped or cut out by laser cutting. Yarious haptics are described, for example, by P. Fechner in Intraokularlinsen, Grundlagen und Operationslehre (Intraocular Lenses, Principles and Operating Techniques), Ferdinand Enke Verlag, Stuttgart 1980.
As already mentioned, the ophthalmic lenses according to the inven~ion have excellent physical parameters, such as a high hardness and oxygen permeability. For example, hardnesses of 60-70 N/mm2 and Dk values of 280-350 units have been measured. Corre-spondingly high hardnesses are otherwise only obtained at the expense of the Dk values, and vice versa. Thus, for example, conventional materials having a hardness of 60-70 N/mm2 have Dk values of less than 100, and materials having Dk values of 150 have a hardness of 40 or less. The abovementioned combination of such a high hardness with such a high oxygen permeability is therefore an outstanding property of the contact lenses and intraocular lenses according to the invention, which distinguishes them consid-erably and unexpectedly from the prior art. On the other hand, the wetting angle is com-p~ratively high, so that it is desirable for the surface of the ophthalmic lenses according to ~ -- 8- ~, t;
the invention to be made more wettable, especially in the case of contact lenses.
This invention thus furthermore relates to a process for hydrophilising the ophthalmic lenses obtainable by the abovementioned processes and to lenses treated in this way. The hydrophilising can be carried out in a manner which is known per se. Suitable processes are, for example, treatment in plasma with gases, graft polymerisation with hydrophilic monomers, introduction of hydroxyl groups by modification of the units of the forrnula I
or oxidation of copolymer constituents.
The treatment of, for example, contact lenses with gases in plasma is already known per se. Examples of gases which can be used are 2~ 3, N2, He, Ar, NH3 or lower alkanes having, for example, up to ~ carbon atoms, such as CH4, by themselves, as a mixture or as a mixture with water vapour. However, the ~eatment in plasma with gases in connection with this invention is not limited to the use of substances which are gases under normal conditions (temperature and pressure). Instead, the term "gases" in this connection also includes, according to the invention, compounds which have such a high vapour pressure that they can produce a low pressure plasma. Examples of such compounds are low molecular weight alkanes, alkenes, alcohols, amines, aldehydes, carboxylic acids, carboxylic acid derivatives, such as hydrophilic esters or arnides, and ethers, each of which can be used by themselves, as a mixture with one another or, for example, as a mixture with oxygen, air and/or water vapour. Low molecular weight in this connection means, in particular, compounds having a molecular weight of up to 200, preferably up to 140, particularly preferably up to 88.
~raft polymerisation with hydrophilic monomers is also akeady known, for example in accordance with EP-A-220 919. It can be carried out in plasma or in solution. Suitable hydrophilic monomers are the hydrophilic vinyl monomers usually used for contact lenses, for example methacrylic acid, hydroxyethyl methacrylate, vinylpyrrolidone, N-vinyl-methylacetamide, dimethylacrylamide or homologues thereof. This hydrophilisationmeasure is preferably carried out in suitable solvents, such as hydrocarbons, for example aromatic hydrocarbons, such as toluene or dimethylbenzene, or aliphatic hydrocarbons, for example hexane, and in the presence of agents which form free radicals, for example per-compounds, for example hydrogen peroxide or peracids.
The units of the formula I always present in the contact lenses or intraocular lenses which have not undergone specif1c surface treatment can be converted, for example by acid tr ~
hydrolysis or in a basic medium in the presence of a hydrogen Iransfer agent, into groups of the formula V
-C~CF-H 1H (V) the presence of which likewise increases the hydrophilicity of the surface. Examples of suitable reagents for this are alkali metals, such as sodium or potassium, preferably in solvents which can transfer hydrogen, such as ethers, in particular cyclic ethers, for example tetrahydrofuran, or in ammonia, or acids, such as inorganic or organic acids, for example hydrochloric acid, sulfuric acid or trifluoroacetic acid. The ophthalmic lenses according to the invention can also be treated oxidatively in solution using oxidising agents, for example hydrogen peroxide or nitric acid.
The inventi~sn is illustrated below with the aid of examples, but these are not intended to limit the invention in any way. Temperatures are stated in degrees Celsius.
A: E~roduction of blanks, semi-finished lenses, contact lenses and intraocular lenses Example 1: Teflon AF 1600 or 2400 granules are melted in an injection moulding machine at 210-220C in a suitable manner and injected into the mould. The injection mould i3 designed as a single- or multi-cavity mould. The follow-up pressure on the moulding composition and the cooling of the injection moulding in the mould are adjusted so that a substantially stress-free blank having a diameter of about 14 mm and a thickness of 6 mm is obtained. Residual stresses can be eliminated by subsequent annealing of the blanks under normal atmosphere or N2 or in vacuo at 110C-140C.
Alternatively, the polymer melted in an extruder is processed to round rods having a dia-meter of about 14 mm. The rods are annealed as a whole or cut into buttons 6 mm thick and annealed.
Example 2a: Granules are injected into an injection mould as described in Example 1. The mould is provided with inserts which are convex in shape. The radii of the inserts corre-spond to the base curves of the desired contact lenses (so-called base curve blanks). The radii are spherical. However, the base curve blanks can also be aspherical in shape, in c~
- lo-particular elliptical. Alternatively, the inserts are provided with an incorporated lens diameter and lens edge. The final contact lens is obtained from these blanks by lathe cutting the front curve.
2b According to this embodiment, the inserts are concave in shape, so that after the corresponding base curve has been machined by lathe cutting, a flat, collecting or scattering lens is obtained. Here also, the final lens diameter and the lens edge are alternatively incorporated.
Example 3: As in Example 1, granules are plasticised in a suitable manner and injected into a contac~ lens mould. The mould is shaped so that it reproduces the desired base curve, diopter, diarneter, bevel and edge of the lens. The base curve is spherical, aspherical or, as a particular embodiment, elliptical, as required.
Example 4: Granules or powder of Teflon AF 1600 or 2400 or a mixture thereof in a balanced amount are heated at 200-220C in a suitable pressing mould and compressed under pressure. The material or contact lens is allowed to cool in the mould, while maintaining the pressure. The mould used is shaped as a button mould, semi-mould(Example 2) or lens mould (Example 3). The amount of granules or powder weighed out depends on the mould used, as follows:
- for a button: 0.5-1.5 g - for a semi-rnould: 0.1-0.9 g - for lenses: 15-100 mg.
Example 5: Granules or powder of Teflon AF 1600 or 2400 are or is plasticised in a suita-ble plasticising unit and the material is pressed through a slit orifice. The resulting film 0.2-0.5 mm thick is formed or pressed directly or later by a forming process, thermo-forming, deep-drawing or compression moulding in a contact lens mould to give a contact lens or intraocular lens. Alternatively, corresponding films are produced by the blowing process.
Example 6: About 8-10 % by weight of granules or powder of Teflon AF 1600 or 2400 are dissolved in a perfluorinated solvent, for example Galden(~' (Montedison) or Fluorinert(g) (3M), if necessary while heating. A film is produced from the solution by stripping off the solvent by heating, a fan or a vacuum. This film is shaped to a contact lens in accordance with one of the forming processes (see Example 5).
Example 7: A solution, obtained according to Example 6, of the copolymer is introduced into a prefabricated mould. The solvent is evaporated off by heating or in vacuo. The mould is constructed so that it reproduces the front face of the lens with its diopter, diameter and lens-edge configuration. The base curve is subsequently shaped using a corresponding punch with the radius incorporated.
Example ~: A solution obtained according to Example 6, is introduced into a prefabricated mould which turnec1 about its own axis. The mould is constructed so that it reproduces the front curve of the contact lens with its diopter, diameter and edge. The solvent is evapo-rated by heating, during which the mould is simultaneously rotated. Various radii of the base curve are obtained by adjusting the speed of rotation (so-called spincast process).
B: Examples for hydrophilising contact lenses or intraocular lenses Example 9: Finished contact lenses according to one of the above examples are exposed to a corona discharge under normal atmosphere to improve the wettability. The contact lenses are then equilibrated with physiological saline solution. Thereafter, the surface can be wetted homogeneously.
Example 10: Contact lenses according to the invention with an untreated surface are exposed to a plasma discharge. This is generated in an atmosphere of 2 or O3. Water vapour can also be ad~nixed to these gases. After a treatment time of 10 seconds to 15 minutes, the lenses have a wetting angle of <40 (without treatmçnt >100). The same results are achieved starting from N2, He, Ar, NH3 or CH~, by themselves or as a mixture.
Example 11: Contact lenses according to the invention with an untreated surface are activated by means of Ar plasma. A hydrophilic surface is produced by graft polymers using hydrophilic monomers such as methacrylic acid, HEMA, methacrylamide, vinyl-pyrrolidone or N-vinylmethylacetamide. The same results are achieved starting from a plasma of N2 or 2-Example 12: The surfaces of contact lenses or intraocular lenses according to the inven-tion having an untreated surface are activated with H2O2, as a powerful agent which forms free radicals, in a solution of hexane and subjected to graft polymerisation by adding hydrophilic monomers, as in Example 11. After eguilibration with physiological saline solution, the wetting of the surface is significantly improved.
Example 13: Contact lenses according to the invention having an untreated surface are exposed to a solution of Na/NH3 or Na/tetrahydrofuran (Tetra Etch~, Gore) in a dipping process. After treatment with acetone and then water, excess reagent is rinsed off and the lenses are equilibrated with physiological saline solution. The treatment is carried out for 1-60 seconds at room temperature or at temperatures up to 100C.
Amorphous fluoropolymers are further developments of polytetrafluoroethylene which has already been known for some decades. Amorphous fluoropolymers are disclosed, for ex-ample, in EP-A-073 087 or EP-A-l l l 343. According to EP-A-073 087, these are copoly-mers which are obtained from tetrafluoroethylene and perfluoro-2,2-dimethyl-1,3-dioxole, and possibly a third monomer, for example propylene, isobutylene or ethylene. Polytetra-fluoroethylene compositions which are prepared, for example, using certain amounts of the abovementioned dioxole or derivatives thereof are disc losed in EP-A- 111 343.
Since 1989, such amorphous fluoropolymers have also been commercially available.Thus, Dupont markets the products Teflon AF 1600 and 2400, in which "AF" means "Amorphous Fluoropolymer". These products are copolymers of tetr~fluoroethylene and perfluoro-2,2-dimethyl-1,3-dioxole.
According to EP-A-073 087, the amorphous copolymers disclosed therein are suitable for uses such as windows for chemical reactions, specifically in processes in which hydrogen fluoride is used or forms. The amorphous copolymers disclosed in EP-A-111 343 are described as being useful in making molded parts, specifically in instances where smooth surfaces are important, such as ball valve seats. The polymers Teflon AF 160Q and 2400 ;
marketed by Dupont are described in the product description accompanying them as being suitable for coatings or coverings for optical devices, including those which are used within wide temperature ranges and in a chemically aggressive environment. Elsewhere in the advertising material it states that Teflon AF is an ideal candidate for optical devices for medicine, military, aerospace and industry.
It has now been found that, surprisingly, ophthalmic lenses having exceptionally advanta-geous properties can be produced from amorphous fluoropolymers. Contact lenses or intraocular lenses according to the invention thus have a combination of high hardness and oxygen perrneability. They moreover have such a high glass transition point that they can be autoclaved. In addition, their crystallinity and refractive index are decidedly low. The refractive index can be, for example, made close to the refractive index of the lacrimal film, so that an optimum course of ray results. The refrac~ive index can be adjusted, for example, by varying the nature and amount of comonomers used. According to the in-vention, for example, toric contact lenses of low refractive index can thus also be pro-duced. If intraocular lenses according to the invention are used, fewer complications in respect of secondary cataract formation are expected in view of the material properties.
If materials having a refractive index of between 1.47 and 1.52 are used and a contact lens geometry which is toric on the inside is used, an artificial residual astigmatism arises between the lacrimal fluid and lens material because of the differences in refractive index, and this then has to be corrected on the front curve of the lens with the aid of a toric surface. The production and fitting of such lenses is very expensive.
On the other hand, if a lens material according to the invention having a refractive index of between 1.31 and 1.33 is used to deal with relatively highly astigmatic corneas, there is either no jump or only a very small jump in refractive index. Correction of the undesirable artificial residual astigmatism is thus unnecessary. This makes the lenses and their fitting considerably cheaper.
If materials of relatively low refractive index are used, there is usually a non-optimal distribution of the overall thickness. In extreme cases, the relatively steep lenticular rise leads to incompatibility. However, this effect can be avoided by using a corneoscleral design. A corneoscleral design having diameters of between 11.5 and 13.5 mm not only leads to a general improvement in compatibility because of the large diameter, but allows a balanced division of the lens between the corneoscleral haptic and the optically active surface. The corneoscleral haptic can be designed perfectly here in respect of compability without taking into consideration the optical requirements. The unfavourable distribution of overall thickness which occurs al: the low refractive index has an effect only in the optically active part and in no way affects the compatibility.
Another great advanlage of the material according to the invention lies in the high oxygen P r 3 ~
permeability, which means that it is particularly predestined for corneoscleral design. In-corporating measures for adequate rinsing behind the contact lens (turbo effect, microla-crimation and the like), it is possible to use the material in combination with the corneo-scleral design under particularly adverse circumstances, and moreover the material is suitable for wearing for several days.
The ophthalmic lenses according to the invention therefore combine a range of favourable parameters such as have not been described for contact lenses or intraocular lenses to date.
The invention therefore relates to ophthalmic lenses consisting essentially of an amorphous copolymer which comprises units of the formula I
--fF fF
O O
(C~a ~CF2)b (I) R/ \R
and units of the formula II
-CF2-CF2- (II) in which a and b independently of one another are zero, one or two, and in which R1 and R2 independently of one another are perfluorinated lower alkyl.
Perfluorinated lower alkyl contains up to 7 carbon atoms, in particular up to 4 carbon atoms, and is, for example, perfluorinated methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl or tert-butyl, preferably trifluoromethyl. -The units of the formula I and of the formula II can be present as blocks or can alternate randomly. The content of units of the forrnula I is preferably at least 10 mol per cent and is particularly 10 to 80 mol %.
The sum of the indices a and b in a unit of the formula I is preferably not greater than two.
The indices a and b are particularly preferably zero. In a specific embodiment, a and b are each zero and Rl and R2 in each case are perfluorinated C~-C4aLkyl, in particular tri-fluoromethyl. According to this embodiment, further comonomers can be dispensed with and the molar Tatio of units of the formula I to units of the forrnula II is in the range from 30:70 to 90:10, preferably in a range from 50:50 to 85: lS. Particularly preferred ratios of units of the formula I to those of the forrnula II are about 50:50 and about ~0:20 ("about"
in this connection is to be understood as meaning a deviation of not more than +10 %).
In addition to the units of the formula I and II, the copolymer can comprise other units in amounts of up to 40 mol % of the copolymer. These units can also be in the form of blocks or can alternate randomly with one another or with units of the formula I and II. Suitable units here are those of the formula III
1R3 (III) in which R3 is a perfluorinated alkyl radical of the formula CnF2n+l, in which n is 1 to 4, or in which R3 is a perfluorinated cycloalkyl radical of the formula CmF2m " in which m is 5 to 8, and/or those of the formula IV
-CX-CX -I I (IV) in which X and X' independently of one another are hydrogen or fluorine and R4 and Rs independently of one another are hydrogen, fluorine, lower alkyl or perfluorinated lower alkyl, excluding those units of the forrnula IV in which X, X', R4 and R5 are fluorine.
A perfluorinated alkyl radical of the forrnula CnF2n+l is, for example, perfluoromethyl, -ethyl or -propyl. A perfluorinated cycloalkyl radical of the formula CmF2m, is, for example, perfluorocyclohexyl or -cyclopentyl. Perfluorinated lower alkyl R4 or R5 is as defined above for Rl/R2. Lower alkyl R4 or Rs has up to 7, preferably up to 4, carbon atoms and is, in particular, methyl, ethyl, propyl or butyl.
The units of the formula IV comprise perfluorinated, partly fluorinated and fluorine-free units. Perfluorinated and fluorine-free units of the formula IV are preferred. The former are those, for example, in which X, X' and Rs are fluorine and R4 is perfluorinated lower S
alkyl. The latter are, for example, those in which X, X' and Rs are hydrogen and R4 is lower alkyl. Partly fluorinated units of the forrnula IV are, for example, those in which X, X' and Rs are hydrogen and R4 is perfluorinated lower aLlcyl.
Units of the formula I and II together with units of the formula III or together with units of the formula IV, for example, can occur in the copolymer of which the ophthalmic lenses according to the invention consist. Combinations of units of the formula I and II with units of the formulae III and IV are also possible.
The total amount of units of the forrnula III and IV, where these are present, is preferably up to 30 mol % of the copolymer, and particularly preferably up to 20 mol % of the copo-lymer. An embodiment of Ihe invention which is likewise preferred comprises, however, ophthalmic lenses of copolymers which consist to the extent of at least 90 mol %, more appropriately to the extent of at least 95 mol %, and particularly preferably exclusively, of units of the formula I and II. Ophthalmic lenses, specif1cally contact lenses, of the com-mercially available materials Teflon AF 1600 and Teflon A~ 2400 or mixtures thereof are most preferred. According to the knowledge of the inventors, these materials are copoly-mers such as are used according to claim 4, containing ~0 mol % and 80-90 mol % respec-tively of units of the fonnula I.
The monomers which are required for the preparation of the copolymers are known or can be prepared in a manner wbich is known per se. For example, monomers which provide units of the formula I in the copolymer are described in US Patent 3 978 030. The mono-mers which provide units of the formula II or IV in the copolymer are all commercially obtainable. The monomers which provide units of the formula III in the copolymer are described in standard works, cf., for example, Houben-Weyl, supplement E~0.
The preparation of amorphous copolymers which are used for the preparation of the contact lenses according to the invention is described, for example, in EP-A-073 087 and EP-A-111 343.
In view of the fact that the copolymers used according to the invention can be processed as thermoplastics, there is an abundance of possibilities of producing contact lenses from them. The amorphous copolymers in the form of, for example, granules, powders or films can in each case be used here as starting materials.
The lenses according to the invention can thus be produced by processes which are known per se, such as static mould casting, spin casting, pressing, deep-drawing, thermoforming, lathe cutting or laser machining.
. .
These process steps are known per se and therefore do not require more detailed explana-tion for the expert. However, liquid monomers or monomer mixtures or solutions of solid monomers which polymerise only in the course of the production of the lens or blank, are usually used as starting materials for the production of contact lenses. The peculiarity of the preparation processes according to the invention is that finished copolymers which are thermoplastic are used as the starting materials. These materials therefore also allow routes to be followed which are not usually taken for the production of contact lenses, alongside the classical contact lens production processes, such as lathe cutting of a button, spin casting or static mould casting in individual moulds, which, in some cases in modirled form, can also be used with the present invention.
Static mould casting can be carried out, for example, by injection moulding. For this, the amorphous copolymer is melted at temperatures of 160-240C, preferably 210-220C, and is injected into the mould by means of an injection moulding machine. If moulds with a base curve and front curve are used, contact lenses can be produced directly. It is further-more possible to produce contact lenses by casting, by in~oducing a solution of the amor-phous copolymer in an organic solvent into a mould with a concave curve and convex curve, after which the solvent is allowed to evaporate. Suitable solvents in this and the fol-lowing processes are, for example, perfluorinated ethers or perfluorinated hydrocarbons.
Spin casting can also be used according to the invention, by introducing a solution of the amorphous copolymer into a mould for spin casting, after which the mould is rotated.
During this operation, the solvent evaporates. The finished contact lens, the dimensions of which can be controlled by the dimensions of the mould, the speed of rotation and the viscosity of the solution introduced, remains in the mould.
Pressing is carried out according to the invention, for example, by melting the amorphous copolymer and pressing it in a mould or by compression moulding a film of the amorphous copolymer. A film of the amorphous copolymer can be produced in a manner which is known per se, for example by extrusion, by blowing or by casting a solution of the amorphous copolymer.
A contact lens can also be produced in a manner which is known per se by deep-drawing or thermoforming from a film produced, for example, as men~ioned above.
Lathe cutting is also suitable as the last process step for the production of contact lenses according to the invention. This always applies i~, for example, a blank obtainable by one s)f the abovementioned processes requires further working. Lathe cutting is to be under-stood as meaning conventional machining of e.g. contact lens buttons. Corresponding blanks can be produced, for example, by injection moulding, extrusion of round rods and division thereof, casting from a solution or casting of a melt. The term contact lens blank in this connection includes buttons or semi-mould products, for example base curve blanks. Typical blanks have thicknesses of 4 or 6 mm and diameters of 10 to 17, for example 12 or 14 mm.
Laser machining can also be used according to the invention, blanks or contact lenses produced by one of the other processes being used as the starting material where they still require additional fineworking of their surface.
Intraocular lenses according to the invention can also be produced in a manner which is known per se, for example by lathe cutling processes or by pressing from powder,granules or film. Different haptics can be employed for intraocular lenses according to the invention. The haptic here can be intregrated into the mould shape, or subsequently shaped or cut out by laser cutting. Yarious haptics are described, for example, by P. Fechner in Intraokularlinsen, Grundlagen und Operationslehre (Intraocular Lenses, Principles and Operating Techniques), Ferdinand Enke Verlag, Stuttgart 1980.
As already mentioned, the ophthalmic lenses according to the inven~ion have excellent physical parameters, such as a high hardness and oxygen permeability. For example, hardnesses of 60-70 N/mm2 and Dk values of 280-350 units have been measured. Corre-spondingly high hardnesses are otherwise only obtained at the expense of the Dk values, and vice versa. Thus, for example, conventional materials having a hardness of 60-70 N/mm2 have Dk values of less than 100, and materials having Dk values of 150 have a hardness of 40 or less. The abovementioned combination of such a high hardness with such a high oxygen permeability is therefore an outstanding property of the contact lenses and intraocular lenses according to the invention, which distinguishes them consid-erably and unexpectedly from the prior art. On the other hand, the wetting angle is com-p~ratively high, so that it is desirable for the surface of the ophthalmic lenses according to ~ -- 8- ~, t;
the invention to be made more wettable, especially in the case of contact lenses.
This invention thus furthermore relates to a process for hydrophilising the ophthalmic lenses obtainable by the abovementioned processes and to lenses treated in this way. The hydrophilising can be carried out in a manner which is known per se. Suitable processes are, for example, treatment in plasma with gases, graft polymerisation with hydrophilic monomers, introduction of hydroxyl groups by modification of the units of the forrnula I
or oxidation of copolymer constituents.
The treatment of, for example, contact lenses with gases in plasma is already known per se. Examples of gases which can be used are 2~ 3, N2, He, Ar, NH3 or lower alkanes having, for example, up to ~ carbon atoms, such as CH4, by themselves, as a mixture or as a mixture with water vapour. However, the ~eatment in plasma with gases in connection with this invention is not limited to the use of substances which are gases under normal conditions (temperature and pressure). Instead, the term "gases" in this connection also includes, according to the invention, compounds which have such a high vapour pressure that they can produce a low pressure plasma. Examples of such compounds are low molecular weight alkanes, alkenes, alcohols, amines, aldehydes, carboxylic acids, carboxylic acid derivatives, such as hydrophilic esters or arnides, and ethers, each of which can be used by themselves, as a mixture with one another or, for example, as a mixture with oxygen, air and/or water vapour. Low molecular weight in this connection means, in particular, compounds having a molecular weight of up to 200, preferably up to 140, particularly preferably up to 88.
~raft polymerisation with hydrophilic monomers is also akeady known, for example in accordance with EP-A-220 919. It can be carried out in plasma or in solution. Suitable hydrophilic monomers are the hydrophilic vinyl monomers usually used for contact lenses, for example methacrylic acid, hydroxyethyl methacrylate, vinylpyrrolidone, N-vinyl-methylacetamide, dimethylacrylamide or homologues thereof. This hydrophilisationmeasure is preferably carried out in suitable solvents, such as hydrocarbons, for example aromatic hydrocarbons, such as toluene or dimethylbenzene, or aliphatic hydrocarbons, for example hexane, and in the presence of agents which form free radicals, for example per-compounds, for example hydrogen peroxide or peracids.
The units of the formula I always present in the contact lenses or intraocular lenses which have not undergone specif1c surface treatment can be converted, for example by acid tr ~
hydrolysis or in a basic medium in the presence of a hydrogen Iransfer agent, into groups of the formula V
-C~CF-H 1H (V) the presence of which likewise increases the hydrophilicity of the surface. Examples of suitable reagents for this are alkali metals, such as sodium or potassium, preferably in solvents which can transfer hydrogen, such as ethers, in particular cyclic ethers, for example tetrahydrofuran, or in ammonia, or acids, such as inorganic or organic acids, for example hydrochloric acid, sulfuric acid or trifluoroacetic acid. The ophthalmic lenses according to the invention can also be treated oxidatively in solution using oxidising agents, for example hydrogen peroxide or nitric acid.
The inventi~sn is illustrated below with the aid of examples, but these are not intended to limit the invention in any way. Temperatures are stated in degrees Celsius.
A: E~roduction of blanks, semi-finished lenses, contact lenses and intraocular lenses Example 1: Teflon AF 1600 or 2400 granules are melted in an injection moulding machine at 210-220C in a suitable manner and injected into the mould. The injection mould i3 designed as a single- or multi-cavity mould. The follow-up pressure on the moulding composition and the cooling of the injection moulding in the mould are adjusted so that a substantially stress-free blank having a diameter of about 14 mm and a thickness of 6 mm is obtained. Residual stresses can be eliminated by subsequent annealing of the blanks under normal atmosphere or N2 or in vacuo at 110C-140C.
Alternatively, the polymer melted in an extruder is processed to round rods having a dia-meter of about 14 mm. The rods are annealed as a whole or cut into buttons 6 mm thick and annealed.
Example 2a: Granules are injected into an injection mould as described in Example 1. The mould is provided with inserts which are convex in shape. The radii of the inserts corre-spond to the base curves of the desired contact lenses (so-called base curve blanks). The radii are spherical. However, the base curve blanks can also be aspherical in shape, in c~
- lo-particular elliptical. Alternatively, the inserts are provided with an incorporated lens diameter and lens edge. The final contact lens is obtained from these blanks by lathe cutting the front curve.
2b According to this embodiment, the inserts are concave in shape, so that after the corresponding base curve has been machined by lathe cutting, a flat, collecting or scattering lens is obtained. Here also, the final lens diameter and the lens edge are alternatively incorporated.
Example 3: As in Example 1, granules are plasticised in a suitable manner and injected into a contac~ lens mould. The mould is shaped so that it reproduces the desired base curve, diopter, diarneter, bevel and edge of the lens. The base curve is spherical, aspherical or, as a particular embodiment, elliptical, as required.
Example 4: Granules or powder of Teflon AF 1600 or 2400 or a mixture thereof in a balanced amount are heated at 200-220C in a suitable pressing mould and compressed under pressure. The material or contact lens is allowed to cool in the mould, while maintaining the pressure. The mould used is shaped as a button mould, semi-mould(Example 2) or lens mould (Example 3). The amount of granules or powder weighed out depends on the mould used, as follows:
- for a button: 0.5-1.5 g - for a semi-rnould: 0.1-0.9 g - for lenses: 15-100 mg.
Example 5: Granules or powder of Teflon AF 1600 or 2400 are or is plasticised in a suita-ble plasticising unit and the material is pressed through a slit orifice. The resulting film 0.2-0.5 mm thick is formed or pressed directly or later by a forming process, thermo-forming, deep-drawing or compression moulding in a contact lens mould to give a contact lens or intraocular lens. Alternatively, corresponding films are produced by the blowing process.
Example 6: About 8-10 % by weight of granules or powder of Teflon AF 1600 or 2400 are dissolved in a perfluorinated solvent, for example Galden(~' (Montedison) or Fluorinert(g) (3M), if necessary while heating. A film is produced from the solution by stripping off the solvent by heating, a fan or a vacuum. This film is shaped to a contact lens in accordance with one of the forming processes (see Example 5).
Example 7: A solution, obtained according to Example 6, of the copolymer is introduced into a prefabricated mould. The solvent is evaporated off by heating or in vacuo. The mould is constructed so that it reproduces the front face of the lens with its diopter, diameter and lens-edge configuration. The base curve is subsequently shaped using a corresponding punch with the radius incorporated.
Example ~: A solution obtained according to Example 6, is introduced into a prefabricated mould which turnec1 about its own axis. The mould is constructed so that it reproduces the front curve of the contact lens with its diopter, diameter and edge. The solvent is evapo-rated by heating, during which the mould is simultaneously rotated. Various radii of the base curve are obtained by adjusting the speed of rotation (so-called spincast process).
B: Examples for hydrophilising contact lenses or intraocular lenses Example 9: Finished contact lenses according to one of the above examples are exposed to a corona discharge under normal atmosphere to improve the wettability. The contact lenses are then equilibrated with physiological saline solution. Thereafter, the surface can be wetted homogeneously.
Example 10: Contact lenses according to the invention with an untreated surface are exposed to a plasma discharge. This is generated in an atmosphere of 2 or O3. Water vapour can also be ad~nixed to these gases. After a treatment time of 10 seconds to 15 minutes, the lenses have a wetting angle of <40 (without treatmçnt >100). The same results are achieved starting from N2, He, Ar, NH3 or CH~, by themselves or as a mixture.
Example 11: Contact lenses according to the invention with an untreated surface are activated by means of Ar plasma. A hydrophilic surface is produced by graft polymers using hydrophilic monomers such as methacrylic acid, HEMA, methacrylamide, vinyl-pyrrolidone or N-vinylmethylacetamide. The same results are achieved starting from a plasma of N2 or 2-Example 12: The surfaces of contact lenses or intraocular lenses according to the inven-tion having an untreated surface are activated with H2O2, as a powerful agent which forms free radicals, in a solution of hexane and subjected to graft polymerisation by adding hydrophilic monomers, as in Example 11. After eguilibration with physiological saline solution, the wetting of the surface is significantly improved.
Example 13: Contact lenses according to the invention having an untreated surface are exposed to a solution of Na/NH3 or Na/tetrahydrofuran (Tetra Etch~, Gore) in a dipping process. After treatment with acetone and then water, excess reagent is rinsed off and the lenses are equilibrated with physiological saline solution. The treatment is carried out for 1-60 seconds at room temperature or at temperatures up to 100C.
Claims (24)
1. An ophthalmic lens essentially consisting of an amorphous copolymer which comprises units of the formula I
(I) and units of the iormula II
-CF2-CF2- (II) in which a and b independently of one another are zero, one or two, and in which R1 and R2 independently of one another are perfluorinated lower alkyl.
(I) and units of the iormula II
-CF2-CF2- (II) in which a and b independently of one another are zero, one or two, and in which R1 and R2 independently of one another are perfluorinated lower alkyl.
2. An ophthalmic lens according to claim 1, in which a and b are zero.
3. An ophthalmic lens according to claim 1, in which a and b are zero and R1 and R2 are perfluorinated C1-C4alkyl.
4. An ophthalmic lens according to claim 3, in which R1 and R2 are trifluoromethyl.
5. An ophthalmic lens according to claim 1, in which the molar ratio of units of the formula I to units of the formula II is in the range from 30:70 to 90:10.
6. An ophthalmic lens according to claim 1, which comprises units of the formula III
(III) in which R3 is a perfluorinated alkyl radical of the formula CnF2n+1, in which n is 1 to 4, or in which R3 is a perfluorinated cycloalkyl radical of the formula CmF2m-1, in which m is 5 to 8, and/or those of the formula IV
(IV) in which X and X' independently of one another are hydrogen or fluorine and R4 and R5 independently of one another are hydrogen, fluorine, lower alkyl or perfluorinated lower alkyl, excluding those units of the formula IV in which X, X', R4 and R5 are fluorine, in amounts of up to 40 mol % of the copolymer.
(III) in which R3 is a perfluorinated alkyl radical of the formula CnF2n+1, in which n is 1 to 4, or in which R3 is a perfluorinated cycloalkyl radical of the formula CmF2m-1, in which m is 5 to 8, and/or those of the formula IV
(IV) in which X and X' independently of one another are hydrogen or fluorine and R4 and R5 independently of one another are hydrogen, fluorine, lower alkyl or perfluorinated lower alkyl, excluding those units of the formula IV in which X, X', R4 and R5 are fluorine, in amounts of up to 40 mol % of the copolymer.
7. An ophthalmic lens according to claim 6, in which the copolymer consists to the extent of at least 90 mol % of units of the formulae I and II.
8. An ophthalmic lens according to claim 6, in which the copolymer comprises units of the formulae III in addition to units of the formula I and II.
9. An ophthalmic lens according to claim 6, in which the copolymer comprises units of the formulae III and IV in addition to units of the formula I and II.
10. An ophthalmic lens according to claim 8, in which a and b are zero.
11. An ophthalmic lens according to claim 9, in which a and b are zero.
12. An ophthalmic lens according to claim 1, which consists of Teflon AF 1600.
13. An ophthalmic lens according to claim 1, which consists of Teflon AF 2400.
14. An ophthalmic lens according to claim 1, which consists of a mixture of Teflon AF
1600 and Teflon AF 2400.
1600 and Teflon AF 2400.
15. An ophthalmic lens according to any one of claims 1 to 14, which is a contact lens.
16. An ophthalmic lens according to any one of claims 1 to 14, which is an intraocular lens.
17. A process for the production of an ophthalmic lens according to claim 1, which com-prises producing the lens, starting from an amorphous copolymer as defined in claim 1, by static mould casting, spin casting, pressing, deep-drawing, thermofoming, lathe cutting or laser machining.
18. The use of an amorphous copolymer as defined in claim 1 for the production of a contact lens.
19. The use of an amorphous copolymer as defined in claim 1 for the production of an intraocular lens.
20. A process for hydrophilising the surface of an ophthalmic lens according to claim 1, which comprises hydrophilising the surface in a manner which is known per se by treatment in plasma with gases, graft polymerisation with hydrophilic monomers, introduction of hydroxyl groups by modification of the units of the formula I or oxidation of the copolymer constituents.
21. A process according to claim 20, wherein the surface is hydrophilised by plasma treatment with gases.
22. A process according to claim 20, wherein the surface is hydrophilised by introduction of hydroxyl groups with an alkali metal in a solvent which transfers hydrogen.
23. A process according to claim 20, wherein the surface is hydrophilised by introduction of hydroxyl groups by means of acid hydrolysis.
24. A contact lens which is obtainable according to any one of the processes of claims 20-23.
FD 4.42/JD
FD 4.42/JD
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH57690 | 1990-02-23 | ||
| CH2135/90-7 | 1990-06-27 | ||
| CH576/90-5 | 1990-06-27 | ||
| CH213590 | 1990-06-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2036782A1 true CA2036782A1 (en) | 1991-08-24 |
Family
ID=25685004
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002036782A Abandoned CA2036782A1 (en) | 1990-02-23 | 1991-02-21 | Ophthalmic lenses based on amorphous fluoropolymers |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0443986A1 (en) |
| JP (1) | JPH05257093A (en) |
| KR (1) | KR910021600A (en) |
| AU (1) | AU642963B2 (en) |
| CA (1) | CA2036782A1 (en) |
| IE (1) | IE910607A1 (en) |
| IL (1) | IL97269A0 (en) |
| PT (1) | PT96840A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999056167A1 (en) * | 1998-04-28 | 1999-11-04 | Toray Industries, Inc. | Process for producing ocular lens |
| US6550915B1 (en) | 1998-12-21 | 2003-04-22 | Bausch & Lomb Incorporated | Surface treatment of fluorinated contact lens materials |
| WO2000037971A1 (en) * | 1998-12-21 | 2000-06-29 | Bausch & Lomb Incorporated | Contact lens articles made from perfluorinated comonomers |
| US7534836B2 (en) * | 2005-07-01 | 2009-05-19 | Bausch & Lomb Incorporated | Biomedical devices |
| US7582704B2 (en) * | 2005-07-01 | 2009-09-01 | Bausch & Lomb Incorporated | Biomedical devices |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01302303A (en) * | 1988-05-31 | 1989-12-06 | Mitsubishi Rayon Co Ltd | Optical fiber having plastic clad and its production |
| US5162391A (en) * | 1989-03-10 | 1992-11-10 | Kuraray Co., Ltd. | Oxygen permeable hard contact lens |
| US5115056A (en) * | 1989-06-20 | 1992-05-19 | Ciba-Geigy Corporation | Fluorine and/or silicone containing poly(alkylene-oxide)-block copolymers and contact lenses thereof |
| US5010141A (en) * | 1989-10-25 | 1991-04-23 | Ciba-Geigy Corporation | Reactive silicone and/or fluorine containing hydrophilic prepolymers and polymers thereof |
-
1991
- 1991-02-14 EP EP91810103A patent/EP0443986A1/en not_active Ceased
- 1991-02-18 IL IL97269A patent/IL97269A0/en unknown
- 1991-02-19 AU AU71183/91A patent/AU642963B2/en not_active Expired - Fee Related
- 1991-02-21 CA CA002036782A patent/CA2036782A1/en not_active Abandoned
- 1991-02-21 PT PT96840A patent/PT96840A/en not_active Application Discontinuation
- 1991-02-22 IE IE060791A patent/IE910607A1/en unknown
- 1991-02-22 JP JP3048591A patent/JPH05257093A/en active Pending
- 1991-02-22 KR KR1019910002900A patent/KR910021600A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| AU7118391A (en) | 1991-08-29 |
| PT96840A (en) | 1993-03-31 |
| IE910607A1 (en) | 1991-08-28 |
| EP0443986A1 (en) | 1991-08-28 |
| IL97269A0 (en) | 1992-05-25 |
| KR910021600A (en) | 1991-12-20 |
| JPH05257093A (en) | 1993-10-08 |
| AU642963B2 (en) | 1993-11-04 |
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