Objective: To evaluate bimatoprost/timolol fixed combination (BTFC) vs latanoprost/timolol fixed combination (LTFC) given each evening over the 12-h intraocular pressure (IOP) diurnal curve.
Methods: A total of 54 eyes of 54 patients (24 with primary open-angle glaucoma (POAG) and 30 with pseudoexfoliative glaucoma (PXG)) were included in this prospective, randomized, evaluator-masked single centre crossover study. Patients with an IOP of >or=19 mmHg, under treatment with prostaglandin analogues, were randomized to BTFC or LTFC for a 12-week treatment period after a 6-week run-in period on timolol maleate 0.5% (one drop in each eye twice each day). Patients were then switched to the opposite treatment for the second period. Six 12-h IOP curves were recorded for each patient at baseline (under treatment with timolol maleate 0.5% BID), week 6 and 12 for each treatment period.
Results: The 12-h IOP (mean (SD)) values were 22.0 (1.0) mmHg at baseline, 17.7 (0.8) mmHg on BTFC, and 18.5 (0.8) mmHg on LTFC (P<0.001). At individual time points, there was a significant difference between groups at 0800, 0100, 1200, 1800, and 2000 hours with BTFC having greater ocular hypotensive effect, P<0.001. The most frequently reported adverse event in the study was conjunctival hyperaemia. Average hyperaemia scores were slightly but significantly lower in the LTFC treatment period (P=0.04).
Conclusion: This study suggests that the evening-dosed BTFC provides better IOP control than that of LTFC over 12 h. However, the IOP difference was small and may not be clinically meaningful.