Objective: To investigate if combined intraocular pressure (IOP)-lowering medication with travoprost/timolol fixed combination and a carbonic anhydrase inhibitor, brinzolamide, is superior to both travoprost monotherapy and travoprost/timolol fixed-combination therapy in primary open-angle glaucoma and ocular hypertension.
Methods: Following a 4-week wash-out period and using 4-week long treatment periods, 20 primary open-angle glaucoma or ocular hypertension patients were treated with evening travoprost 0.004%, then switched to evening travoprost 0.004%/timolol 0.5% fixed combination, and finally the treatment was combined with adjunctive twice-daily brinzolamide 1% ophthalmic suspension. Both eyes were treated, but only one eye per patient (the eye with the higher mean diurnal IOP at baseline), was evaluated. IOP was measured at 8 a.m., 12 noon and 4 p.m. at baseline and at the end of each treatment period.
Results: Mean diurnal IOP (mean (SD)) at baseline was 28.5 (7.3) mmHg which decreased to 22.3 (6.3) mmHg on travoprost, 19.2 (3.4) mmHg on travoprost/timolol fixed combination and 17.3 (3.4) mmHg when the brinzolamide was added to the travoprost/timolol combination (ANOVA, contrast test, p<0.003 for all comparisons). The individual time point IOP values showed similar and significant stepwise differences.
Conclusion: Adjunctive brinzolamide medication provided further IOP decrease in patients receiving evening-dosed travoprost/timolol fixed combination. The travoprost/timolol fixed combination was significantly more effective in IOP reduction than travoprost monotherapy, which by itself induced a significant IOP decrease compared to the untreated baseline value. The results of this open label study suggest that combined therapy with travoprost/timolol fixed combination and brinzolamide is clinically useful for IOP-lowering in primary open-angle glaucoma and ocular hypertension.