Purpose: To evaluate the quality of 24-hour intraocular pressure (IOP) control between morning- and evening-dosed travoprost in primary open-angle glaucoma patients.
Design: Prospective, crossover, double-masked comparison.
Methods: After a 6-week medicine-free period, 33 patients were randomized to receive travoprost dosed in the morning or evening. After 8 weeks of treatment, a 24-hour IOP curve was performed at 6 am, 10 am, 2 pm, 6 pm, 10 pm, and 2 am. Patients were then treated with the opposite dosing regimen for another 8 weeks, after which the 24-hour IOP curve was repeated.
Main outcome measures: Twenty-four-hour IOP.
Results: The untreated mean 24-hour IOP was 23.6+/-2.0 mmHg. There were no differences for mean 24-hour IOP between the morning (17.5+/-1.9 mmHg) and evening (17.3+/-1.9 mmHg) dosings (P = 0.7). At 10 am, the evening dosing provided a statistically lower IOP (17.2+/-2.1 mmHg) than the morning dosing (19.1+/-2.5 mmHg) (P = 0.02). Evening dosing demonstrated a statistically lower 24-hour fluctuation of IOP (3.2+/-1.0 mmHg) than morning dosing (4.0+/-1.5 mmHg) (P = 0.01). Safety was similar, with conjunctival hyperemia being the most common adverse event (n = 9 [27% for morning dosing] and n = 11 [33% for evening dosing], P = 0.6).
Conclusions: This study suggests that both morning and evening dosings of travoprost provide effective 24-hour IOP reduction. However, the evening dosing of travoprost demonstrates slightly greater daytime efficacy, with a narrower range of 24-hour pressure.