Efficacy and safety of fixed combinations of latanoprost/timolol and dorzolamide/timolol in open-angle glaucoma or ocular hypertension

Aims To compare intraocular pressure (IOP) reductions with fixed-combination (FC) latanoprost/timolol once daily in the evening vsFC dorzolamide/timolol twice daily. Methods This evaluator-masked, multicentre, controlled clinical trial randomized subjects with primary open-angle glaucoma or ocular hypertension with IOP insufficiently responsive to Β-blocker therapy (screening IOP>21 and <37 mm Hg) to FC latanoprost-timolol (N=135) or FC dorzolamide/timolol (N=135). At screening, baseline, and after 4 and 12 weeks of therapy, IOP was measured three times at 0800, 1200, and 1600 hours. Adverse events were recorded at each visit. The primary efficacy end point was whether either FC could be shown to be inferior to the other with respect to change in mean daytime IOP from baseline to week 12.ResultsMean daytime IOP levels were similar at baseline. Mean reductions in daytime IOP from baseline to week 12 were -9.7 mm Hg for FC latanoprost-timolol and -9.5 mm Hg for FC dorzolamide/timolol. The difference between FC latanoprost/timolol-FC dorzolamide-timolol was -0.2 mm Hg (95% confidence interval (CI), -0.8 to -0.4 mm Hg). The upper bound of the 95% CI was <1.5 mm Hg, indicating that neither FC is inferior to the other. However, a significantly greater percentage of subjects treated with FC latanoprost/timolol achieved IOP levels ≤16 and ≤15 mm Hg (P≤0.01). Both treatments were well tolerated. Conclusions When Β-blocker therapy is inadequate, either FC may achieve the desired IOP level, but FC latanoprost/timolol more oftenly achieves a pressure of ≤16 mm Hg. Both FCs were well tolerated.