The effect of 0.25% apraclonidine in preventing intraocular pressure elevation after Nd : YAG laser posterior capsulotomy

Purpose. The efficacy and adverse effects of 0.25% apraclonidine on intraoc ular pressure (IOP) after Nd: YAG laser posterior capsulotomy were investig ated, and the results were compared with placebo, 0.50% timolol maleate and 1% apraclonidine. Methods. Eighty eyes were randomly assigned to four groups of 20 eyes. In a double-masked design, the groups were treated with placebo (group I), 0.50 % timolol maleate (group 2), 1% apraclonidine (group 3), 0.25% apraclonidin e (group 4) one hour before and five minutes after Nd:YAG laser posterior c apsulotomy. IOP was measured by applanation tonometry I hour before (baseli ne IOP) and 1, 3, 24 hours after capsulotomy. Results. The average baseline IOP increased respectively 3.90 +/- 5.35, 5.9 5 +/- 5.32, 1.15 +/- 3.20 mmHg in the first group 1, 3 and 24 hours post-tr eatment. There were significant differences between baseline IOP and 1 and 3 hours but not at 24 hours (p=0.004, p=0.001, p=0.13). IOP increased 0.40 +/- 4.08, 0.75 +/- 5.33, 0.80 +/- 6.03 mmHg in the second group at the same times. The differences between the average baseline IOP and the 1, 3 and 2 4 h measurement were not significant (p=0.83, p=0.65, p=0.93). In the third group, IOP decreased 3.70 +/- 2.40, 3.30 +/- 2.47, 2.65 +/- 1.56 mmHg at t he measurement times, with significant differences between the average base line IOP and the 1, 3 and 24 hour measurements (p=0.001, p=0.0001, p=0.01). In the fourth group IOP increased 0.35 +/- 3.32 mmHg at 1 hour, but decrea sed 1.25 +/- 3.41, 0.90 +/- 2. 07 mmHg at 3 and 24 hours. The differences w ere not significant (p = 0.94, p = 0.16, p = 0.08). When the 0.25% and 1% a praclonidine groups were compared, there were significant differences betwe en the average IOP at 1 hour in both groups but not at 3 and 24 hours (p=0. 01, p = 0.17, p = 0.21). Similarly, there were no significant differences b etween the average IOP at the same times when the 0.25% apraclonidine group was compared with the timolol group (p = 0.30, p = 0.08, p = 0.16). Some s ystemic and local side effects were seen in the timolol and 1% apraclonidin e groups, but none with 0.25% apraclonidine. Conclusions. It was concluded that 0.25% apraclonidine is effective in prev enting the early elevation of IOP after Nd:YAG laser posterior capsulotomy and may offer an alternative to 0.50% timolol maleate and 1% apraclonidine.