Laser microsclerostomy for primary open angle glaucoma: A review of laser mechanisms and delivery systems

Abstract

SUMMARYA number of different lasers and delivery systems are currently used in experimental sclerostomy procedures.

A comparison of the efficacy of Holmium laser sclerostomy ab externo versus trabeculectomy in the treatment of glaucoma

“…In the initial studies on laser sclerostomy, ah interno or ah extano, involving animal eyes, blockage of the fistula by iris tissue prolapsing or by fibrin or cellular debris was a common complication in the early and intermediate term. 2 -4 There have been varying reports of closure of sclerostomy by iris tissue in procedures performed on Nd:Y AG peripheral iridectomy (8) Trabeculectomy (I): trabeculectomy + topical treatment (2) Trabeculectomy (2); trabeculectomy + topical treatment (1) Ocular massage + topical treatment (2) glaucoma patients. In an earlier series of 26 episodes of Holmium laser thermal sclerostomy ah extano studied by Hoskins et al '" iris incarceration was seen in all but 1 phakic patient but was a rare event in aphakic or pseudo phakic patients.…”

“…While a gonio scopic delivery of laser energy overcomes this problem, it tends to be limited by technical difficulties. 1 An ab externo approach with specially designed probes, on the other hand, can help to reduce the extent of conjunctival dissec tion and keep the procedure quick and minimally invasive. THC:YAG (,Holmium') laser sclerostomy ab externo is the best known of the laser sclerostomies and recent reports have been encouraging.…”

Experimental studies on nonpenetrating filtration surgery using the CO2 laser

“…Various types of laser procedures have been introduced to simplify and improve glaucoma drainage surgery. Laser microsclerostomy has been performed ab interno [1] or ab externo using a holmium laser [10,11], erbium:YAG [12,26], excimer laser [2,5,22], or CO 2 laser [2,4,15,25]. Klink et al [14] reported deep sclerectomy in eyes of dead pigs using the erbium:YAG laser.…”