Solution for removing cataracts via liquefracture

Abstract

An improved solution for use in the removal of cataractous lenses via liquefracture is described. The liquefracture solution contains a viscosity-enhancing agent to increase the residence time of the solution in the heating chamber of the liquefracture handpiece, thereby increasing the expulsion force of the solution from the handpiece (i.e., “pulse force”). An agent that releases gas when the liquefracture solution is heated in the handpiece may also be included in the solution, thereby also enhancing the pulse force of the solution upon expulsion from the handpiece. The solution preferably also contains a partially water-soluble agent that forms a temporarily insoluble precipitate when heated in a liquefracture handpiece. The precipitate acts as an abrasive agent when expelled with the liquefracture solution from the handpiece, thereby facilitating the cutting and disintegration of the cataractous lens material.

1 . A method of removing a cataract by means of liquefracture, which comprises utilizing in said method a liquefracture solution comprising: 
 a viscosity enhancing agent in an amount sufficient to increase the residence time of the liquefracture solution in a heating chamber of a liquefracture handpiece, when said solution is heated in said chamber;    an ophthalmically acceptable, conductive vehicle for said viscosity-enhancing agent; and    an effective amount of an ophthalmically acceptable, transient abrasive agent.    
     
     
         2 . A method according to  claim 1 , wherein the ophthalmically acceptable vehicle comprises a balanced salt solution.  
     
     
         3 . A method according to  claim 2 , wherein the liquefracture solution has an osmolality of 200 to 200 mOsm/kg.  
     
     
         4 . A method according to  claim 2 , wherein the liquefracture solution has a viscosity of from greater than 1 cps to 15 cps.  
     
     
         5 . A method according to  claim 4 , wherein the liquefracture solution has a viscosity of from 2 to 7 cps.  
     
     
         6 . A method according to  claim 1 , wherein the viscosity enhancing agent is selected form the group consisting of proteoglycans, cellulose derivatives, collagen and modified collagens, galactomannans, xanthan gum, gellan gums, alginate, chitosans, polyvinyl alcohol, carboxy vinyl polymers, and combinations thereof.  
     
     
         7 . A method according to  claim 6 , wherein the viscosity enhancing agent is a cellulose derivative.  
     
     
         8 . A method according to  claim 7 , wherein the cellulose derivative is selected from the group consisting of HPMC, CMC, HEC and combinations thereof.  
     
     
         9 . A method according to  claim 8 , wherein the cellulose derivative comprises HPMC.  
     
     
         10 . A method according to  claim 9 , wherein the HPMC has a molecular weight in the range of 86,000 to 260,000.  
     
     
         11 . A method according to  claim 1 , wherein the transient abrasive agent is a cellulose derivative.  
     
     
         12 . A method according to  claim 11 , wherein the cellulose derivative comprises HPMC.  
     
     
         13 . A method according to  claim 1 , wherein the liquefracture solution further comprises an amount of gas-generating agent sufficient to enhance the pulse force of the solution upon expulsion of the solution from a liquefracture handpiece.