Deformable-elastic intraocular lens

Abstract

A deformable-elastic intraocular lens comprising a deformable-elastic lens body of crosslinked acrylic material formed of copolymers of methacrylate and acrylate esters which are relatively hard and relatively soft at body temperature, crosslinked with a diacrylate ester to produce an acrylic copolymer having a substantially tack-free surface, a crosslink density of between . .0.5×10 -2 and 1.5×10 -2 .!. .Iadd.0.23×10 -1 and 1.66×10 -1 .Iaddend.moles per liter, and glass transition temperature in the range of -30° C. to 25° C., a tensile modulus between 1000 and 3000 psi and a elongation a break of 100% or greater.

I claim: 
     
       1. A deformable-elastic intraocular lens (IOL), comprising: a deformable-elastic lens body of crosslinked acrylic material comprising copolymers of methacrylate and a acrylate esters which are relatively hard and . .relative.!. .Iadd.relatively .Iaddend.soft at body temperature, crosslinked with a diacrylate ester wherein the crosslinked acrylic material has a substantially tack-free surface, a crosslink density of between . .0.5×10 -2  and 1.5×10 -2  .!. .Iadd.0.23×10 -1  and 1.66×10 -1  .Iaddend.moles per liter, a glass transition temperature between -30° and 25° C., a tensile modulus between 1000 and 3000 psi and an elongation at break of at least 100%; and   flexible haptics attached to the lens body to position the lens body in the eye.   
     
     
       2. The IOL of claim 1 wherein the lens body is formed by chemically crosslinking the diacrylate ester with a partially polymerized mixture of the copolymers, curing the crosslinked acrylic and holding the cured crosslinked acrylic at a temperature below its Beta-relaxation temperature while machining the lens body. 
     
     
       3. The IOL of claim 2 wherein each haptic is attached by forcing an enlarged end thereof into a smaller hole in an edge of the lens body. 
     
     
       4. A deformable-elastic intraocular lens (IOL), comprising: a deformable-elastic lens body of crosslinked acrylic material formed by mixing copolymers of methacrylate and acrylate esters which are relatively hard and relatively soft at body temperature, with a diacrylate ester to produce an acrylic material having crosslinked density of between . .0.5×10 -2  and 1.5×10 -2  .!. .Iadd.0.23×10 -1  and 1.66×10 -1  .Iaddend.moles per liter and a glass transition temperature of between -30° and 25` C.; and   flexible haptics attached to the lens body to position the lens body in the eye.   
     
     
       5. The IOL of claim 4 wherein the copolymers are mixed and partially polymerized before mixing with the diacrylate ester. 
     
     
       6. A deformable-elastic intraocular lens body of a crosslinked acrylic material comprising copolymers of methacrylate and acrylate esters which are relatively hard and relatively soft at body temperature, crosslinked with a diacrylate ester wherein the acrylic material has a substantially tack-free surface, a crosslink density of between . .0.5×10 -2  and 1.5×10 -2  .!. .Iadd.0.23×10 -1  and 1.66×10 -1  .Iaddend.moles per liter, a glass transition temperature between -30° and 25° C., a tensile modulus between 1000 and 3000 psi and an elongation at break of at least 100%. 
     
     
       7. A deformable-elastic intraocular lens body of a crosslinked acrylic material formed by reacting copolymers of methacrylate and acrylate esters which are relatively hard and relatively soft at body temperature to produce a reaction product having a glass transition temperature between -30° and 25° C., partially polymerizing the reaction product and mixing it with a diacrylate ester to produce a crosslinked acrylic having a crosslink density of between . .0.5×10 -2  and 1.5×10 -2  .!. .Iadd.0.23×10 -1  and 1.66×10 -1  .Iaddend.moles per liter, curing the acrylic and machining the lens body therefrom. 
     
     
       8. The lens body of claim 7 wherein the relatively hard methacrylate ester is a fluoroacrylate. 
     
     
       9. The lens body of claim 7 wherein reaction product comprises ethyl methacrylate, trifluoro ethyl methacrylate and an acrylate ester present in percent by weight concentrations of 25 to 45, 5 to 25 and 30 to 60%, respectively. 
     
     
       10. The lens body of claim 9 wherein the acrylate ester is selected from n-butyl acrylate, ethyl acrylate and 2-ethyl hexyl acrylate. 
     
     
       11. The lens body of claim 10 wherein the diacrylate ester is present in a percent by weight concentration of 0.5 to 3.0%. 
     
     
       12. The lens of body of claim 11 wherein the diacrylate ester is selected from ethylene glycol dimethacrylate, propylene glycol dimethacrylate, and ethylene glycol diacrylate. 
     
     
       13. A method of forming a deformable-elastic intraocular lens body comprising the steps of: (a) mixing copolymers of methacrylate and acrylate ester which are relatively hard and relatively soft at body temperature;   (b) partially polymerizing the product of Step (a);   (c) chemically crosslinking the product of Step (b) with a diacrylate ester;   (d) curing the product to Step (c); and   (e) forming a lens body having a predetermined optical characteristic from the product of Step (d).   
     
     
       14. The method of claim 13 wherein Step (e) comprises holding the product of Step (d) at a temperature below its Beta-relaxation temperature while machining the lens body. 
     
     
       15. The method of claim 13 wherein the methacrylate and acrylate esters are mixed together in approximately a 45 to 55% by weight ratio. 
     
     
       16. The method of claim 15 wherein the diacrylate ester of Step (C) is present in a percent composition by weight of 0.5 to 3.0%. 
     
     
       17. The method of claim 16 further including the mixing of a UV-absorber and a free radical initiator in Step (a). 
     
     
       18. The method of claim 13 wherein the relatively hard methacrylate ester is a fluoroacrylate. 
     
     
       19. The method of claim 18 wherein Step (a) further including mixing the fluoroacrylate in a concentration range by weight of between 5 and 25% with ethyl methacrylate in a concentration range by weight of between 25 and 45% and an acrylate ester selected from n-butyl acrylate, ethylacrylate or 2-ethyl hexyl acrylate in a concentration range by weight of between 30 and 60%. 
     
     
       20. The method of claim 19 wherein the fluoroacrylate is trifluoro ethyl methacrylate. 
     
     
       21. The method of claim 20 wherein Step (a) further includes the mixing of a UV-absorber in a concentration range by weight of between 0 and 10% and a free radical initiator in a concentration range by weight of 0.05 and 0.2%.