Injectionable visoelastic ophthalmic gel

Abstract

An improved injectionable viscoelastic gel for use in opthalmic surgical and treatment procedures, wherein the gelling agent is a high molecular weight polyacrylamide or polymethacrylamide.

What is claimed is: 
     
       1. An injectionable viscoelastic gel particularly adapted for use in ophthalmic surgical procedures and treatments .[.which.]..Iadd., said .Iaddend.gel consisting essentially of from about 2 to about 5 percent by weight of a polymer selected from polyacrylamide and polymethacrylamide, said polymer having a molecular weight of from about 1 to about 6 million.[.;.]..Iadd., .Iaddend.from about 0.4 to about 8.6 percent by weight sodium chloride, from about 0.075 to about 0.3 percent by weight .[.postassium.]. .Iadd.potassium .Iaddend.chloride, from about 0.04 to about 0.33 percent by weight calcium chloride, from about 0.02 to about 0.04 percent by weight magnesium chloride hexahydrate, from about 0.3 to about 0.4 percent by weight sodium acetate, from about 0.15 to about 0.20 percent by weight of a buffer, remainder water. 
     
     
       2. A gel as defined in claim 1 wherein said polymer is polyacrylamide. 
     
     
       3. A gel as defined in claim 1 wherein said polymer is present in an amount of from about 3.5 to about 4.5 percent by weight. 
     
     
       4. A gel as defined in claim 1 wherein said polymer has a molecular weight of from about 4.5 to about 5.5 million. 
     
     
       5. A gel as defined in claim 1 wherein said buffer is sodium citrate dihydrate. 
     
     
       6. A gel as defined in claim 1 consisting essentially of about 4 percent by weight of said polymer having a molecular weight of about 5 million, about 0.049 percent by weight sodium chloride, about 0.075 percent by weight potassium chloride, about 0.048 percent by weight calcium chloride, about 0.03 percent by weight magnesium chloride hexahydrate, about 0.17 percent by weight sodium citrate dihydrate, remainder water. .Iadd. 
     
     
       7.  A method for protecting ocular tissue during ophthalmic surgery which comprises injecting into an ocular chamber prior to said surgery an amount of viscoelastic gel sufficient to prevent mechanical damage and denudation of said ocular tissue during said surgery, said viscoelastic gel comprising a polymer selected from polyacrylamide, polymethacrylamide and a copolymer of acrylamide and methacrylamide, said polymer having a molecular weight of from about 1 to 6 million, and a pharmaceutically acceptable diluent therefor. .Iaddend. .Iadd.8. The method of claim 7 wherein said surgical procedure is an anterior segment surgical procedure. .Iaddend. .Iadd.9. The method of claim 8 wherein said anterior segment surgical procedure is cataract removal, corneal transplant, keratoplasty or bullous   
     
     
        rhegmatogenous retinal detachment. .Iaddend. .Iadd.10.  The method of claim 7 wherein said polymer is present in an amount between about 2 to about 5 percent by weight of said viscoelastic gel. .Iaddend. .Iadd.11. The method of claim 7 wherein said polymer is present in an amount between about 3.5 to about 4.5 percent by weight of said viscoelastic gel. .Iaddend. .Iadd.12. The method of claim 7 wherein said polymer is present in an amount between about 4.5 to about 5.5 percent by weight of said viscoelastic gel. .Iaddend. .Iadd.13. The method of claim 7 wherein said polymer is present in an amount between about 4 percent by weight of said viscoelastic gel. .Iaddend. .Iadd.14. The method of claim 7 wherein said polymer is polyacrylamide. .Iaddend. .Iadd.15. The method of claim 7 wherein said viscoelastic gel comprises (a) 2 to 5 percent by weight of said polymer;   (b) 0.4 to 8.6 percent by weight sodium chloride;   (c) 0.075 to 0.3 percent by weight potassium chloride;   (d) 0.04 to 0.33 percent by weight calcium chloride;   (e) 0.02 to 0.04 percent by weight magnesium chloride hexahydrate;   (f) 0.3 to 0.4 percent by weight sodium acetate;   (g) 0.15 to 0.20 percent by weight buffering agent; and   
     
     
       (h) remainder water. .Iaddend. .Iadd.16.  The method of claim 15, wherein said buffering agent is sodium citrate dihydrate. .Iaddend. .Iadd.17. The method of claim 7 wherein said viscoelastic gel consists essentially of about 4 percent by weight of said polymer having a molecular weight of about 5 million, about 0.49 percent by weight sodium chloride, about 0.075 percent by weight potassium chloride, about 0.048 percent by weight calcium, about 0.03 percent by weight magnesium chloride hexahydrate, about 0.17 percent by weight sodium citrate dihydrate, remainder water. .Iaddend.