Classifications

• • 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

Definitions

• the invention relates to contact and intraocular lenses containing absorbers of ultraviolet radiation and to the method of their production.
• the undamaged eye possesses the ability to resist, for a certain time, the ultraviolet radiation that is a constituent of daylight. Slow biochemical and physiological changes caused by the radiation in the eye are accelerated to a considerable extent if the eye is damaged in whatever way. On long-term action of ultraviolet radiation, the protecting mechanism of the eye fails and an irreversible damage of cornea, lens or retina results. According to the latest findings, the danger of damaging the vision considerably increases if the atmospheric ozone layer deteriorates.
• UV absorbers are substances capable of absorbing the radiation in this wavelength range.
• a self-evident prerequisite for these substances is that,if used, they are incorporated into the lens material in such a way that they cannot be removed by common extraction procedures since only thus they can form an effective protection of the eye against ultraviolet radiation.
• the aim of this invention is contact and intraocular lenses containing UV absorbers and their preparation by polymerization of a mixture of suitable monomers, initiators, crosslinking agent and polymerizable UV absorbers in such a way that the resulting contact or intraocular lens absorbs all the transmitting ultraviolet light.
• the object of the invention is contact and intraocular lenses with UV absorbers formed by a polymer consisting of 89 to 99.6 wt. % of vinyl monomers, 0.2 to 6 wt.% of polymerizable UV absorbers, 0.1 to 3 wt. % of a crosslinking
• the contact and intraocular lenses according to the invention are formed by a polymer containing vinyl monomers selected from the group comprising alkyl acrylates and methacrylates, hydroxyalkyl acrylates and methacrylates,
• fluoroalkyl acrylates and methacrylates (alkyloxy)alkyl acrylates and methacrylates, (acyloxy) lkyl acrylates and methacrylates, acylaminoalkyi acrylates and methacrylates, (alkylsulfinyl)alkyl acrylates and methacrylates, (alkylsul ⁇ fonyl)alkyl acrylates andmethacrylates, tris(alkyloxy)silyl-
• alkyl acrylates and methacrylates N-vinylpyrrolidone, N-vinylpiperidone and their combinations, where alkyl is an alkyl with 1 to 4 carbon atoms.
• the polymer for the contact and intraocular lenses according to this invention contains, as polymerizable UV
• absorbers substances selected from the group of substances comprising the substances of general formula I or II,
• Rl, R2 are hydrogen, acryloyloxy, methacryloyloxy,
• R3, R4 are hydrogen, hydroxy, halogen, cyano, alkylox , alkyl, (alkyloxy)alkyl, hydroxyalkyl groups, the alkyls being alkyls with 1 to 4 carbon atoms or III or IV
• R is acryloyl or methacryloyl group or their mixtures.
• crosslinking agents substances selected from the group comprising acrylic and methacrylic esters of dihydric alcohols, amino alcohols, amines, allyl acrylates and methacrylates and diallyl esters of dicarboxylic acids are suitable.
• polymerization initiators azo and peroxy initiators and initiators cleavable by UV radiation are used.
• the method of preparation of contact and intraocular lenses consists in polymerization or copolymerization of vinyl monomers performed in the presence of polymerizable UV absorbers, a crosslinking agent and a polymerization initiator straight in the respective moulds.
• the preparation of both contact and intraocular lenses proceeds in such a way that polymerization mixtures containing a polymerizable UV absorber are charged into moulds and polymerized.
• transmittance is plotted of a contact lens prepared from a mixture of monomers containing N-vinylpyr ⁇ rolidone and 2-(acetyloxy)ethyl methacrylate and a UV absorber, 2-hydroxy-4-(2-(methacryloyloxy)ethyloxy)benzo ⁇ phenone, in given concentrations prepared according to Example 2.
• Central thickness of the lens is 0.13 mm.
• Figure 3 is UV spectrum of 2-hydroxy-4-(2-(methacryloyl ⁇ oxy)ethyloxy)benzophenone.
• a stock solution of the polymerizable mixture contained: 25 ml 2-hydroxyethyl methacrylate containing 0.12 wt. % ethylene dimethacrylate, 30 1 ethylene dimethacrylate (its content in the polymerizable mixture is 0.3 wt. %) and 0.025g 2,2 ' -azobis(isobutyronitrile) . From the stock solution, the following mixtures containing various amounts of the UV absorber, 2-hydroxy-4-methacryloyloxy-2'-(methoxycarbonyl) benzophenone, were prepared:
• the following mixture of monomers wa ⁇ used for prepa- ration of intraocular lenses 1.02 g methacrylic acid, 31.4 g 2-hydroxyethyl methacrylate, 3.29 g glycerol, 0.07 g ethylene dimethacrylate, 0.14 g diisopropyl peroxycarbonate and 1.63 g 2-hydroxy-4-(2-(methacryloyloxy)ethyloxy)ben ⁇ zophenone.
• Argon was bubbled through the polymerization mixture which was then charged into polymerization moulds in amounts of 40 ⁇ l. Polymerization was performed in the atmosphere of carbon dioxide at 70°C for 2 hours. Intraocular lenses were soaked in a 5 % hydrogen carbonate solution and then in physiological solution.
• Intraocular lenses were prepared from the following polymerization mixture: 65 g 2-hydroxyethyl methacrylate, 6.5 g glycerol, 0.14 g ethylene dimethacrylate, 0.25 g 2,2'-azo- bis(isobutyronitrile) , 3.2 g 4-methacryloyloxy-2-hydroxy- benzophenone.
• the resulting lenses were worked up analogously to Example 4.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Materials For Medical Uses (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (4)

Citations (5)

• 1995
  • 1995-06-20 CZ CZ951614A patent/CZ284063B6/cs not_active IP Right Cessation
• 1996
  • 1996-06-19 WO PCT/CZ1996/000016 patent/WO1997001114A1/en active Application Filing

Patent Citations (5)

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