Ocular Lens

Abstract

A method of making an ocular lens device (and resulting lens device) from a polyolefin copolymer material having a crosslinking component, wherein the material is processed to remove unwanted reaction byproducts that can contribute to reduced transparency of the polyolefin copolymer material in the ocular environment of the eye.

I claim: 
     
         1 . A method of preparing an implantable ocular lens device comprising:
 cationically polymerizing a mixture to produce a thermoset copolymer, wherein the mixture includes i) at least one branched alkene monomer, ii) at least one olefin monomer having a pendant benzocyclobutene (BCB) group, and iii) a monomer that terminates ends of the copolymer with allyl groups, wherein the thermoset copolymer comprises allyl groups of the ends of thermoset copolymer corresponding to the monomer of iii); and   processing the thermoset copolymer to form at least part of the implantable ocular lens device, wherein the processing includes heating the thermoset copolymer such that the thermoset copolymer undergoes crosslinking to form a resultant polymer that is part of the implantable ocular lens device.   
     
     
         2 . A method according to  claim 1 , wherein:
 wherein the branched alkene monomer of i) is an isoolefin selected from the group consisting of isobutylene, 2-methyl-1-butene, 2-methyl-1-pentene, 2-methyl-1-hexene, and combinations thereof.   
     
     
         3 . A method according to 1, wherein:
 the mixture includes a compound comprising chlorine, and the allyl groups of the ends of thermoset copolymer corresponding to the monomer of iii) substantially eliminates chlorine that could otherwise reside on the ends of the thermoset copolymer and contribute to clouding of implantable ocular lens device.   
     
     
         4 . A method according to  claim 1 , wherein:
 the monomer of iii) comprises allyltrimethylsilane.   
     
     
         5 . A method according to  claim 1 , wherein:
 the thermoset copolymer comprises a random distribution of a plurality of constitutional units that include constitutional units corresponding to the at least one branched alkene monomer of i) and constitutional units corresponding to the at least one olefin monomer having a pendant benzocyclobutene (BCB) group of ii).   
     
     
         6 . A method according to  claim 1 , wherein:
 the monomer of iii) is added to the mixture subsequent to reacting the at least one branched alkene monomer of i) and the at least one olefin monomer having a pendant benzocyclobutene (BCB) group of ii).   
     
     
         7 . The method according to  claim 1 , wherein:
 the at least one olefin monomer having a pendant benzocyclobutene (BCB) group of ii) and the monomer of iii) are both added to the mixture without quenching cationic polymerization involving the at least one branched alkene monomer of i).   
     
     
         8 . A method according to  claim 1 , wherein:
 the at least one olefin monomer having a pendant BCB group of ii) includes a monomer having the formula   
       
         
           
           
               
               
           
         
         wherein R is hydrogen or an alkyl group and n is 0. 
       
     
     
         9 . A method according to  claim 8 , wherein:
 the at least one olefin monomer having a pendant BCB group of ii) includes 4-vinylbenzocyclobutene or 2-(4-benzocyclobutenyl)-propene.   
     
     
         10 . A method according to  claim 1 , wherein:
 the at least one olefin monomer having a pendant BCB group of ii) includes a monomer having the formula   
       
         
           
           
               
               
           
         
         wherein R is alkyl group and n is an integer ranging from 0-3. 
       
     
     
         11 . A method according to  claim 10 , wherein:
 the at least one olefin monomer having a pendant BCB group of ii) includes 2-methyl-3-(4-benzocyclobutenyl)-propene.   
     
     
         12 . A method according to  claim 1 , wherein:
 the mixture further includes iv) a glass-forming monomer selected from the group consisting of styrene, indene, α-methylstyrene, p-tert-butylstyrene, p-chlorostyrene, norbornene, and combinations thereof.   
     
     
         13 . A method according to  claim 1 , wherein:
 the mixture further includes at least one initiator suitable for cationic polymerization of the mixture.   
     
     
         14 . A method according to  claim 13 , wherein:
 the at least one initiator is selected from the group including tricumyl ether, di-t-butyl pyrilidone, and a Lewis-acid initiator (preferably titanium tetrachloride).   
     
     
         15 . A method according to  claim 1 , wherein:
 the mixture further includes a solvent system suitable for cationic polymerization of the mixture.   
     
     
         16 . A method according to  claim 15 , wherein:
 the solvent system of comprises a polar solvent (preferably methyl chloride).   
     
     
         17 . A method according to  claim 15 , wherein:
 the solvent system comprises a nonpolar solvent (preferably methylcyclohexane).   
     
     
         18 . A method according to  claim 1 , wherein:
 the thermoset copolymer is a random copolymer.   
     
     
         19 . A method according to  claim 1 , wherein:
 the thermoset copolymer is a block copolymer.   
     
     
         20 . A method according to  claim 1 , wherein:
 the implantable ocular lens device comprises an intraocular lens.   
     
     
         21 . A method of forming an implantable ocular lens device comprising:
 providing a cationically polymerized thermoset copolymer comprising a plurality of constitutional units that include constitutional units corresponding to the at least one branched alkene monomer and constitutional units corresponding to the at least one olefin monomer having a pendant benzocyclobutene (BCB) group, and wherein the cationically polymerized thermoset polymer further comprises allyl groups that terminate ends of the cationically polymerized copolymer; and   processing the thermoset copolymer to form at least part of the implantable ocular lens device, wherein the processing includes heating the thermoset copolymer such that the thermoset copolymer undergoes crosslinking to form a resultant polymer that is part of the implantable ocular lens device.   
     
     
         22 . A method according to  claim 21 , wherein:
 the allyl groups that terminate the ends of thermoset copolymer substantially eliminate chlorine that could otherwise reside on the ends of the thermoset copolymer and contribute to clouding of implantable ocular lens device.   
     
     
         23 . A method according to  claim 21 , wherein:
 the thermoset copolymer comprises a random distribution of a plurality of constitutional units that include constitutional units corresponding to the at least one branched alkene monomer and constitutional units corresponding to the at least one olefin monomer having a pendant benzocyclobutene (BCB) group.   
     
     
         24 . A method according to  claim 21 , wherein:
 the implantable medical device comprises an intraocular lens.   
     
     
         25 . A method of preparing a thermoset copolymer suitable for use in forming an implantable ocular lens device, the method comprising:
 cationically polymerizing a mixture to produce a thermoset copolymer. wherein the mixture includes i) at least one branched alkene monomer, ii) at least one olefin monomer having a pendant benzocyclobutene (BCB) group, and iii) a monomer that terminates ends of the copolymer with allyl groups, wherein the thermoset copolymer further comprises allyl groups of the ends of thermoset copolymer.   
     
     
         26 . A method according to  claim 25 , wherein:
 the thermoset copolymer comprises a random distribution of a plurality of constitutional units that include constitutional units corresponding to the at least one branched alkene monomer of i) and constitutional units corresponding to the at least one olefin monomer having a pendant benzocyclobutene (BCB) group of ii).   
     
     
         27 . A method according to  claim 25 , wherein:
 the allyl groups that terminate the ends of thermoset copolymer substantially eliminate chlorine that could otherwise reside on the ends of the thermoset copolymer and contribute to clouding of the implantable ocular lens device.