OBJECTIVE: To evaluate the 24 h efficacy and safety of the travoprost/timolol maleate fixed combination (TTFC) versus travoprost when both are dosed in the evening in primary open-angle glaucoma patients.METHODS: Prospective, double-masked, crossover, active-controlled, randomised 24 h comparison. After a 6 week medicine-free period, patients were randomised to either TTFC or travoprost for 8 weeks and were then switched to the opposite treatment for another 8 weeks. At the end of the washout and treatment periods, a 24 h pressure curve was performed.RESULTS: Thirty-two patients completed the study. The TTFC group demonstrated a lower absolute intraocular pressure level (2.4 mm Hg) for the 24 h curve and at all time points, compared with travoprost (p0.05).CONCLUSIONS: This study suggests that when both drugs are dosed in the evening the TTFC provides improved intraocular pressure reduction, compared with travoprost, over the 24 h curve and for each individual time point in primary open-angle glaucoma patients.