[Argon laser trabeculoplasty]

Abstract

There is currently a general consensus to perform argon laser trabeculoplasty (ALT) onto the 360 degrees of the trabecular ring to obtain the best long term results; but in two sessions a month apart with, during each session, 50 burns of a true 50 mu laser spot on 180 degrees, a 0.1 sec exposure time and a power high enough to create a tiny but visible trabecular reaction on the anterior edge of the posterior trabecular meshwork. During the first three hours after treatment, the main complication is raised intraocular pressure (IOP) which occurs in between 14% and 33% of the cases with a 10 mmHg rise above the initial IOP. In end stage glaucomas, a very close monitoring is mandatory during these first hours. Pretreatment with apraclonidine drops can dramatically reduce this complication. Our results and those of the literature with the same follow-up show that ALT seems effective in phakic chronic open-angle glaucomas (COAG) in half of the cases for about five years with a 10% new failure rate per year. The youngest patients, the aphakic patients and all the cases with trabecular severe disorganisation display the worst results. ALT must be considered to be a physical treatment - initially powerful but with decreasing efficacy in the long term. It should be used in presurgical glaucomas when IOP does not exceed 30 mmHg with intensive medical treatment and in intermediate stages of the disease where it is more effective.