Circadian control of IOP comparable with a single drop of bimatoprost, travoprost, study suggests

Single drops of bimatoprost and travoprost appear to provide comparable control of circadian IOP in patients with glaucoma or ocular hypertension when applied while lying in bed or sitting, a small, 36-hour clinical study found.

"This marks the first time a single drop has been used for this type of evaluation," the study authors said.

Ronald E. Frenkel, MD, and colleagues randomly assigned 19 patients with glaucoma or ocular hypertension to receive a single drop of Lumigan (bimatoprost 0.03%, Allergan) in one eye and a single drop of Travatan Z (travoprost 0.004%, Alcon) in the other eye after completing a washout. All eye drops were administered at 8 p.m., and IOP was measured with patients lying in bed or sitting in 4-hour intervals for 36 hours.

Mean IOP at baseline was 20.6 mm Hg in the bimatoprost group and 21.1 mm Hg in the travoprost group, the study authors said. However, at each subsequent measurement, both bimatoprost and travoprost had significantly reduced IOP from baseline.

In the sitting position, mean IOP after instillation of a single drop of medication ranged from 17.8 mm Hg to 19.7 mm Hg in the bimatoprost group and from 17.2 mm Hg to 20 mm Hg in the travoprost group during the first 24 hours, according to the study.

In the supine position, IOP ranged from 21.6 mm Hg to 24.9 mm Hg in the bimatoprost group and from 21.1 mm Hg to 25.2 mm Hg in the travoprost group.

Both medications continued to control IOP for the remaining 12 hours, with IOP averaging 20.5 mm Hg in the bimatoprost group and 21.5 mm Hg in the travoprost group at 36 hours.

"Study limitations included single-drop instillation and a short follow-up time," the study authors said.