Comparison of the Ocular Hypotensive Efficacy of Adjunctive Brimonidine 0.15% or Brinzolamide 1% in Combination with Travoprost 0.004%

Purpose: To compare efficacies of adjunctive therapy with brimonidine 0.15% and adjunctive therapy with brinzolamide 1% in combination with travoprost 0.004%. Design: Three-month randomized, parallel-group, double-masked, multicenter clinical trial. Participants: Patients with primary open-angle glaucoma, exfoliation glaucoma, or ocular hypertension with intraocular pressure (IOP) > 18 mmHg on monotherapy with travoprost (N = 163). Methods: Patients were randomized to receive adjunctive therapy with twice-daily brimonidine (N = 79) or twice-daily brinzolamide (N = 84). Treatment efficacy was assessed after 1 and 3 months of combination therapy. Intraocular pressure was measured at 8 am, noon, and 4 pm at baseline (on travoprost monotherapy) and after 3 months of combination therapy. Mean diurnal IOP was defined as the average of the IOP measurements at these 3 time points. Adverse events were recorded at each visit. Main Outcome Measure: Difference between treatment groups in mean diurnal IOP at month 3, adjusted for difference in baseline IOP, using analysis of covariance. Results: Mean diurnal IOPs (± standard error of the mean) at baseline were 21.7±0.33 mmHg in the brimonidine group and 21.1±0.29 mmHg in the brinzolamide group (P = 0.16). Mean diurnal IOPs at month 3 were 19.6±0.41 mmHg in the brimonidine group and 18.4±0.33 mm Hg in the brinzolamide group (P = 0.019). At month 3, mean diurnal IOPs, adjusted for difference in baseline IOP, were 19.3±0.27 in the brimonidine group and 18.6±0.25 in the brinzolamide group (P = 0.035). Conclusions: The combination of travoprost and brinzolamide was statistically significantly more efficacious than the combination of travoprost and brimonidine in lowering IOP. The clinical significance of this difference is uncertain.