Objective: Brimonidine tartrate 0.5%, a topical alpha 2-adrenergic agonist, was administered before and after argon laser trabeculoplasty (ALT) to evaluate its efficacy against postoperative intraocular pressure (IOP) spikes.

Methods: Two randomized, double-masked, vehicle-controlled investigations evaluated four treatment regimens in 471 patients undergoing ALT for glaucoma or ocular hypertension. The combined results are presented.

Results: IOP elevations > or = 10 mm Hg occurred in 1% (1/122) of the patients who received brimonidine before and after ALT; in 2% (2/119) of those receiving brimonidine before and vehicle after; in 1% (1/114) of those receiving vehicle before and brimonidine after; and in 23% (27/116) of those receiving vehicle before and after (P < .001).

Conclusions: The brimonidine regimens were generally effective and well-tolerated ocularly and systemically.