Comparison of the effects of latanoprost, travoprost, and bimatoprost on circadian intraocular pressure in patients with glaucoma or ocular hypertension

Purpose: To compare 24-hour reduction in intraocular pressure (IOP) by latanoprost 0.005%, travoprost 0.004%, and bimatoprost 0.03% in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OH). Design: Randomized, double-masked, crossover study. Participants: Twenty-four patients with POAG and 20 with OH. Methods: Patients were treated with latanoprost, travoprost, and bimatoprost for 1 month. The treatment sequence was randomized, and washout lasted 30 days for each trial drug. Four 24-hour tonometric curves were recorded for each patient: 1 at baseline and 1 after each treatment period. Main Outcome Measures: Intraocular pressure was measured at 3, 6, and 9 am; noon; 3, 6, and 9 pm; and midnight by 2 treatment-masked well-trained evaluators using a handheld electronic tonometer with the patient in supine and sitting positions and a Goldmann applanation tonometer with the patient sitting at the slit lamp. Supine systemic blood pressure was recorded at the same times. A randomized-blocks analysis of variance was used to analyze data. Results: All 3 drugs were highly effective in reducing IOP when compared to baseline. Mean IOP reductions were similar after the 3 prostaglandin analogs, and none of the differences among treatments reached statistical significance. The drugs' effect was significantly greater during the daytime (9 am-9 pm) than during the nighttime (midnight-6 am) with all prostaglandin analogs. In 7 of 44 patients (16%), nocturnal IOP was significantly higher than diurnal IOP, both at baseline and under the 3 prostaglandin analogs. Conclusions: From a clinical point of view, the overall results seem to indicate that the 3 prostaglandin analogs are powerful agents in controlling round-the-clock IOP in POAG and OH patients.