Evaluation of circadian control of intraocular pressure after a single drop of bimatoprost 0.03% or travoprost 0.004%.

Purpose: To compare circadian control of intraocular pressure (IOP) after a single drop of bimatoprost 0.03% or travoprost 0.004% in patients with glaucoma or ocular hypertension.

Methods: Randomized, investigator-masked, paired-eye, 36-hour clinical comparison. After completing a washout, patients (N = 19) were randomized to a single drop of bimatoprost in one eye and travoprost in the other eye at 8 PM. At night, IOP was measured with patients lying in bed and sitting. IOP was measured every 4 h for 36 h in total.

Results: Mean IOP at 8 PM (prior to drop instillation) was 20.6 mmHg (18.5-24.0 mmHg) with the bimatoprost eye group and 21.1 mmHg (18.5-26.5 mmHg) with the travoprost eye group (p = 0.369). At every measurement, both bimatoprost and travoprost significantly reduced IOP from baseline. During the first 24 h, mean IOP (while sitting) after instillation of a single drop of study medication ranged from 17.8 to 19.7 mmHg with bimatoprost and from 17.2 to 20.0 mmHg with travoprost (p > or = 0.075). While in the supine position, IOP ranged from 21.6 to 24.9 mmHg with bimatoprost and from 21.1 to 25.2 mmHg with travoprost (p > or = 0.351). Both medications continued to control IOP for the remaining 12 h, with IOP approaching baseline after 36 h (mean IOP of 20.5 mmHg with bimatoprost and 21.5 mmHg with travoprost, p = 0.381). Study limitations included single-drop instillation and a short follow-up time.

Conclusions: This marks the first time a single drop has been used for this type of evaluation. These findings suggest that both bimatoprost and travoprost provide comparable and lasting control of circadian IOP in patients with glaucoma or ocular hypertension.