PROTECTIVE EFFICACY OF SODIUM HYALURONATE ON THE CORNEAL ENDOTHELIUM AGAINST THE DAMAGE-INDUCED BY SONICATION

The protective efficacy of sodium hyaluronate (Na-Hn) on the corneal e ndothelium against the damage induced by sonication was investigated u sing enucleated rabbit eyes and Na-HA fluorescence labeled with 5-amin ofluorescein (FA-HA). The anterior chamber was reformed by injecting a 1%, solution of FA-HA, and then sonication, irrigation and aspiration were performed in the anterior chamber rising a phaco-needle attached to phacoemulsification and aspiration (PEA) equipment. The protective efficacy was evaluated by the area of damaged corneal endothelium. Wh en the anterior chamber was reformed by the solution of FA-HA with a m olecular weight of 2010 x 10(3) (FA-HA (2010 x 10(3)) group), most of the FA-HA was eliminated within 20 seconds after starting the irrigati on and aspiration, and the area of damaged endothelium was the same wi th the case when the FA-HA ln was not pre-injected (Control group). On the other hand, when the anterior chamber was reformed by the solutio n of FA-HA with a molecular weight or 1130 x 10(3) (FA-HA (1130 x 10(3 )) group), the FA-HA was gradually eliminated after mixing with an irr igating solution, and the area of damaged endothelium was significantl y smaller than those of the Control and FA-HA (2010 x 10(3)) groups. T hese results suggest that the corneal endothelial damage induced by PE R can be avoided by pre-injecting a viscoelastic material which can re main in the anterior chamber during PEA.