Bimatoprost may help latanoprost non-responders

PARMA, Italy — Bimatoprost can be effective in lowering intraocular pressure in patients who have little or no response to latanoprost treatment, according to a small study.

“Our study results are encouraging because there are some patients with glaucoma or ocular hypertension that just do not respond to treatment with latanoprost,” said Stefano Gandolfi, MD, of the University of Parma here.

He and a colleague conducted a randomized clinical trial with a crossover design — two 30-day treatment phases with a 30-day washout in between. Fifteen patients with either ocular hypertension or primary open-angle glaucoma were enrolled. Patients were at least 50 years old and had an IOP of more than 22 mm Hg on current therapy. Additionally, the patients had less than 10% reduction of IOP in both eyes in previous treatment with latanoprost 0.005%. The primary efficacy end point was IOP reduction.

All patients were given bimatoprost in only one eye for 30 days after the washout period. The other eye was treated with a placebo. IOP reading were taken at 8 a.m., 12:00p.m., 4:00p.m., 8:00p.m. and 12:00a.m. The researchers also measured visual acuity and conjunctival hyperemia.

Mean baseline IOP was 24.7 mm Hg before washout and 24.8 mm Hg after washout. Both medications lowered IOP, but eyes receiving 30 days of bimatoprost had a mean IOP of 18 mm Hg and eyes receiving latanoprost had a mean IOP of 24 mm Hg (P < .0001). IOP readings in the bimatoprost patients were significantly lower than the baseline readings at every time point throughout the day. The most common adverse event reported was trace to mild conjunctival hyperemia, reported more often in the eye on bimatoprost, Dr. Gandolfi said.