FORMATION OF FREE-RADICALS DURING PHACOEMULSIFICATION

During phacoemulsification cavitation bubbles are formed. These bubble s are believed to be one source of damage to corneal endothelium seen after phacoemulsification. Free radicals are induced whenever cavitati on bubbles implode. The aim of this study was to confirm the initiatio n of free radicals by phacoemulsification and to correlate the power o f ultrasound in the phacoemulsification process to the amount of free radicals formed, using both in vitro and in vivo techniques. The forma tion of free radicals was determined by adding luminol to a buffer and measuring the chemoluminescensce in vitro and in rabbit eyes (Lumacou nter(TM) 2080 or a single-photon-counting apparatus) during phacoemuls ification. The data obtained show that free radicals are formed during phacoemulsification and that the amount of free radicals correlates w ith the power of ultrasound. Furthermore, the radical formation could be inhibited by the radical scavengers SOD, Healon(R) and Healon(R) GV . These results were achieved both in vitro in the test tube and in vi vo in rabbit eyes. By showing that the addition of SOD to the irrigati on buffer during phacoemulsification decreases the corneal endothelial cell damage, we show that free radicals could have a role in postoper ative complications seen clinically.