Circadian IOP-lowering efficacy of travoprost 0.004% ophthalmic solution compared to latanoprost 0.005%

Purpose: The primary objective of this study was to determine the intraocular pressure-(IOP) lowering efficacy over two consecutive 24-h periods of travoprost 0.004% ophthalmic solution (Travatan dagger) compared to latanoprost 0.005% (Xalatan double dagger) dosed once daily in patients with primary open-angle glaucoma or ocular hypertension. Methods: This was a double-masked trial conducted at the Hospital Clinico San Carlos, Madrid, Spain. The primary objective of this study was to determine the IOP lowering efficacy of travoprost and latanoprost. During the eligibility visit, patients' IOP was measured throughout two consecutive 24-h periods every 4h. Patients were then randomized to travoprost or latanoprost (one drop at 8 p.m. daily for 2 weeks). Sixty-two patients were randomized (travoprost n = 32; latanoprost n = 30). IOP was measured at week 2 every 4 h throughout two 24-h periods. All measurements were taken in both supine and sitting positions with the aid of Perkins applanation tonometry. Limitations of the study include a small sample size (due to the difficulty in recruiting patients in a study of this type) which enrolled only Caucasian patients and a short study duration. However, with 25 subjects per group, there was at least 90% power to detect a mean IOP change from baseline of 2.9 mmHg and 80% power to detect a difference of 2.5 mmHg between treatments. Results: Patients on travoprost therapy showed lower mean 1013 levels than those on latanoprost. This difference was statistically significant (p < 0.05) at 12,16, 20, 24, 36, 40, and 48h after the last dose for the supine position. The mean IOPs in the supine position throughout the first and the second 24-h period of the week 2 visit as well as for the 48-h visit were statistically lower (p < 0.05) for the travoprost group. Adverse events were mild and included hyperemia and corneal staining. Travoprost and latanoprost were both well tolerated. Conclusion: Mean IOP values were significantly lower for patients on travoprost for the majority of time points in the supine position.