Effect of bimatoprost on patients with primary open-angle glaucoma or ocular hypertension who are nonresponders to latanoprost

Purpose: To test the efficacy of bimatoprost 0.03% 2D for lowering intraocular pressure (IOP) in patients affected by primary open-angle glaucoma or ocular hypertension who did not respond to treatment with latanoprost 0.005% 2D. Design: Prospective, randomized clinical trial with a cross over design (two 30-day treatment phases with a 30-day washout phase in between). Participants: Fifteen patients were enrolled. Random allocation to treatment to a single eye only of every subject. Eligibility criteria: (1) IOP > 22 mmHg in both eyes on current treatment (on three separate readings > 24 hours apart), (2) angle wide open in both eyes, (3) no pseudoexfoliation and/or pigment dispersion in either eye, (4) documented medical history consistent with < 10% IOP decrease in both eyes on 2-month treatment with latanoprost 0.005% every day. Method: The following variables were measured at each study visit: (1) IOP (Goldmann applanation tonometry, 5 readings, 8 AM, 12 noon, 4 Pm, 8 Pm, and 12 midnight); (2) visual acuity (Early Treatment of Diabetic Retinopathy Study chart, logarithm of the minimum angle of resolution); (3) estimate of conjunctival hyperemia based on 5 standard photographs (graded as "none" "trace," "mild," "moderate," and "severe"). Main Outcome Measure: IOP. Results: IOP data (mean and standard deviation) were the following: baseline = 24.7 +/- 0.9 mmHg, after washout = 24.8 +/- 1.1 mmHg, after latanoprost phase = 24.1 +/- 0.9 mmHg, after bimatoprost phase = 18.1 +/- 1.7 mmHg. IOP on bimatoprost proved lower than both baseline (P < 0.0001) and latanoprost (P = 0.0001). Thirteen of 15 patients showed a greater than or equal to 20% IOP decrease with bimatoprost treatment. None of the 15 patients showed a greater than or equal to 20% decrease of IOP after 30 days of latanoprost treatment. No significant IOP changes were observed in the fellow untreated eye in each patient throughout the study. Trace-to-mild conjunctival hyperemia was recorded more often with bimatoprost phase (P = 0.035). Conclusions. Thirteen of 15 patients, who were nonresponders to latanoprost, 0.005%, 2D, were successfully treated with bimatoprost, 0.03%, 2D. Bimatoprost treatment was associated with a higher incidence of trace-to-mild conjunctival hyperemia than latanoprost.