USE OF THE GIANT-PULSE NDYAG LASER FOR AB-EXTERNO SCLEROSTOMY IN RABBITS AND HUMANS

The giant-pulse Neodymium:YAG laser, a recently developed laser source , delivers up to 200 W of peak power at pulse widths of 20 or 40 msec. The instrument can create a sclerostomy with minimal surrounding dama ge and, consequently, relatively little postsurgical inflammation and scarring. We tested its efficacy in performing ab-externo sclerostomy in 10 adult pigmented rabbits and in five patients with end-stage glau coma. All of the animal eyes were hypotonus immediately after the proc edure. However, the intraocular pressure increased gradually, and by t he third day, returned to presurgical levels in all of the eyes. All f ive of the glaucoma patients treated had patent sclerostomies followin g the procedure. They all had early hypotony, but after 3 months, four of the five sclerostomies apparently failed. The giant-pulse Nd:YAG l aser appears useful for performing sclerostomy, but modifications are needed to solve the problems of early hypotony and late closure of the fistulula.