Prophylactic Use of Brimonidine or Apraclonidine for Intraocular Pressure Elevation following Laser Iridotomy

Suh, Won Jun; Cha, Soon Cheol

Abstract

PURPOSE: The purpose of this study was to evaluate and compare the prophylactic effect of brimonidine 0.2% and apraclonidine 0.5% in preventing intraocular pressure(IOP) elevation in patients undergoing laser iridotomy.
METHODS
The 24-hour, placebo-controlled, randomized, clinical trial was conducted to determine the efficacy of brimonidine 0.2% and apraclonidine 0.5% in controlling IOP after combined argon and Nd:YAG laser peripheral iridotomy. The 110 eyes(56 eyes with angle closure glaucoma, 54 eyes with narrow occludable angle) were randomized to receive brimonidine 0.2%, apraclonidine 0.5% or artificial tear(as placebo) 20 minutes before the procedure. IOP was measured before and 1, 2, and 24 hours after the procedure by masked observer using Goldmann applanation tonometry. The difference between preoperative(baseline) IOP and the highest postoperative IOP was recorded as the maximum IOP rise.
RESULTS
The mean of maximum IOP rise was 1.1+/-5.6 mmHg in the brimonidine group, 1.0+/-2.9 mmHg in the apraclonidine group and 4.7+/-7.6 mmHg in the placebo group. There was statistically significant decrease in IOP in both drug groups compared to the placebo group(p<0.05). The incidence of maximum IOP rise greater than 5 mmHg was 18.2%(6/33 eyes) in the brimonidine group, 11.4%(4/35 eyes) in the apraclonidine group and 42.9%(18/42 eyes) in the placebo group. But no statistical difference was found between the brimonidine group and apraclonidine group(p>0.05).
CONCLUSIONS
Both brimonidine 0.2% and apraclonidine 0.5% were significantly effective in preventing IOP spike following laser iridotomy procedure. There was a tendency toward less efficacy with brimonidine 0.2% compared to apraclonidine 0.5%, but this was statistically insignificant.