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

Purpose: To compare the around-the-clock intraocular pressure (IOP) reduction induced by latanoprost 0.005%, bimatoprost 0.3% and travoprost 0.2% in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). Methods: In a cross-over trial, 10 patients with POAG and 10 with OHT were treated with latanoprost, travoprost, and bimatoprost for one month. Treatment sequence was randomized. All patients underwent 4 around-the-clock tonometric curves: a baseline and after one month of treatment with each trial drug. IOP was measured by two well-trained evaluators masked to treatment assignment at 3, 6, 9 a.m., and at noon, and at 3, 6, 9 p.m., and at midnight using a handheld electronic tonometer (TonoPen XL, Bio-Rad, Glendale, California) with the patient in supine and sitting positions, and a Goldmann applanation tonometer with the patient sitting at the slit lamp. Systemic blood pressure was recorded at the same times. Sample size was estimated assuming a difference in mean IOP of 2.5 mmHg as clinically relevant, = 0.05, 1-ß = 0.90, and a sd = 2 mmHg. Results: The Goldmann measurements showed that bimatoprost was significantly (p<0.05) more effective than travoprost at 3 a.m. and at noon, and it was more effective than latanoprost only at noon. The supine position measurements showed that bimatoprost was more effective than travoprost at 3, 9, 12 a.m., and it was more effective than latanoprost at 9 a.m. and 6 p.m.. Travoprost was more effective than latanoprost at 3 and 6 p.m., while latanoprost was more effective than travoprost at noon. Conclusions: All the three drugs were highly effective in reducing IOP. Bimatoprost seemed to be more effective in the morning hours.