Objective: To compare the intraocular pressure (IOP)-lowering effect and safety of topical brimonidine to that of timolol, and to study the additive effect of topical brimonidine to topical prostaglandin (PG) analogues in 475 patients with either ocular hypertension or primary open angle glaucoma.
Methods: The primary endpoint was the mean IOP change from the baseline at 0 and 2 hours at week 4.
Results: The mean changes were -4.7 +/- 2.1 (S. D.) in the timolol and -4.0 +/- 2.0 mmHg in the brimonidine group (p = 0.0138). The 95% confidence interval of the inter-group difference was greater than the pre-determined criterion of non-inferiority of brimonidine to timolol. When added to PG analogues, the IOP-lowering effect of brimonidine (-2.9 +/- 1.8 mmHg) was greater than that of the placebo (-2.1 +/- 1.8 mmHg) (p = 0.0010). No appreciable adverse side effects were encountered.
Conclusion: Topical brimonidine showed an additive IOP-lowering effect to topical PG analogues, although its IOP-lowering effect was inferior to topical timolol as monotherapy.