Extended wear ophthalmic lens
An ophthalmic lens suited for extended-wear periods of at least one day on the eye without a clinically significant amount of corneal swelling and without substantial wearer discomfort. The lens has a balance of oxygen permeability and ion or water permeability, with the ion or water permeability being sufficient to provide good on-eye movement, such that a good tear exchange occurs between the lens and the eye. A preferred lens is a copolymerization product of a oxyperm macromer and an ionoperm monomer. The invention encompasses extended wear contact lenses, which include a core having oxygen transmission and ion transmission pathways extending from the inner surface to the outer surface.
1. A contact lens comprising a polymeric material formed from a prepolymerization mixture including:
(a) at least one siloxane-containing macromer, wherein said at least one siloxane-containing macromer comprises a hydrophilic group, a polydimethylsiloxane segment and a poly(disubstituted siloxane) segment including a substituent selected from the group consisting of a partly fluorinated alkyl, an alkenyl, an aryl, a cyanoalkyl, an aminoalkyl, a hydroxyalkyl, alk-NH-alk-NH 2 , -alk-(OCH 2 CH 2 ) m —(OCH 2 ) p —OR 7 , and combinations thereof, wherein alk is alkylene, R 7 is hydrogen or C 1 -C 6 alkyl, m and p independently of one another are an integer from 0 to 10;
(b) at least one hydrophilic monomer; and
(c) a cross-linking agent,
the contact lens characterized by having a tensile modulus of less than about 3.0 MPa and producing less than 10% corneal swelling after a period of wear of 7 days including normal sleep periods.
2. The contact lens of claim 1 wherein said hydrophilic group is selected from the group consisting of polyoxyethylene, urethane, urea, amide, amine, hydroxyl and combinations thereof.
3. The contact lens of claim 2 , wherein the tensile modulus is between about 0.5 to about 1.5 MPa.
4. The contact lens of claim 2 , wherein the cross-linking agent is selected from the group consisting of allyl(meth)acrylate, lower alkylene glycol di(meth)acrylate, poly lower alkylene glycol di(meth)acrylate, lower alkylene di(meth)acrylate, divinyl ether, divinyl sulfone, divinylbenzene, trivinylbenzene, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, bisphenol A di(meth)acrylate, methylenebis(meth)acrylamide, triallyl phthalate, and diallyl phthalate.
5. The contact lens of claim 2 , wherein the hydrophilic monomer comprises N-vinylpyrrolidone.
6. The contact lens of claim 2 , wherein the prepolymerization mixture comprises an additional siloxane-containing macromer or monomer which is a polydimethylsiloxane.
7. The contact lens of claim 6 , wherein the contact lens is coated with a layer of a hydrophilic polymeric material.
8. The contact lens of claim 1 , wherein the prepolymerization mixture comprises at least one hydrophobic monomer selected from the group consisting of methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, isobutyl acrylate, isooctyl acrylate, isodecyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene, vinyl chloride, vinylidene chloride, acrylonitrile, 1-butene, butadiene, methacrylonitrile, vinyl toluene, vinyl ethyl ether, perfluorohexylethylthiocarbonylaminoethyl methacrylate, isobomyl methacrylate, trifluoroethyl methacrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl (meth)acrylate, tris-trimethylsilyloxy-silyl-propylmethacrylate, 3-methacryloxypropylpentamethyldisiloxane, bis(methacryloxypropyl) tetramethyldisiloxane and combinations thereof.
9. The contact lens of claim 8 wherein the hydrophobic monomer is isobomyl methacrylate or tris-trimethylsilyloxy-silyl-propyl methacrylate.
10. The contact lens of claim 8 producing less than 7% corneal swelling after a period of wear of 7 days including normal sleep periods.
11. The contact lens of claim 8 producing less than 5% corneal swelling after a period of wear of 7 days including normal sleep periods.