SUMMARY
Thirty-twoeyeswith open angle glaucoma received argon laser trabeculoplasty. Sixteen eyes were pretreatead with topical 0.5% aspirin and sixteen eyes received placebo. The intraocular pressure was evaluated 1,2, 4 and 24 hours following trabeculoplasty. The ocular hypertension following laser trabeculoplasty was confirmed and it was more prevalent 1 to 2 hours after treatment. The more conspicous intraocular pressure rises tended to be more prevalent in the aspirin treated eyes (50%) than in the control group (25%). The etiopathogenetic mechanism is discussed.