BRIMONIDINE IN THE PREVENTION OF INTRAOCULAR-PRESSURE ELEVATION FOLLOWING ARGON-LASER TRABECULOPLASTY

Objective: To evaluate the efficacy of 0.5% brimonidine tartrate, an a lpha2-adrenergic agonist, in preventing intraocular pressure (IOP) ele vation following argon laser trabeculoplasty. Design: In a multicenter , double-masked, randomized study, 248 patients (248 eyes) who underwe nt argon laser trabeculoplasty were allocated to four treatment groups : (1) brimonidine administered before and after the procedure; (2) bri monidine administered before the procedure; (3) brimonidine administer ed after the procedure; and (4) a vehicle administered before and afte r the procedure.Results: In the first 3 hours after argon laser trabec uloplasty, only one (0.54%) of the 183 brimonidine-treated patients ha d a postlaser IOP increase of 10 mm Hg or more, while increases of thi s magnitude occurred in 13 (23%) of the 56 patients who received only the vehicle (P<.001). The three brimonidine-treatment groups demonstra ted significant mean reductions in IOP from the pretrabeculoplasty lev el (-4 to -8 mm Hg), whereas the vehicle-treated group showed an incre ase in mean IOP (4 mm Hg). Side effects associated with brimonidine tr eatment included conjunctival blanching (40.9%), lid retraction (7.6%) , and a slight lowering of the systolic blood pressure. Conclusions: O ne drop of 0.5% brimonidine administered either before or after surger y was found to be efficacious and safe in preventing posttrabeculoplas ty elevations in IOP.