Bimatoprost 0.01% vs bimatoprost 0.03%: a 12-month prospective trial of clinical and in vivo confocal microscopy in glaucoma patients

Purpose To evaluate the safety of two commercially available formulations of bimatoprost eye drops: 0.03 and 0.01% ophthalmic solutions. Methods This was a randomized, prospective, parallel-group, open-label, cohort study. A total of 60 glaucoma patients (60 eyes) under bimatoprost 0.03% monotherapy since at least 1 year were enrolled. Selected patients were randomized to receive a single drop of bimatoprost 0.01% ( n =30) or bimatoprost 0.03% ( n =30) ophthalmic solutions for 12 months. Statistical analysis was performed using paired t -test and repeated measures ANOVA test. Results Global clinical score (the sum of pruritus, stinging/burning, blurred vision, sticky eye sensation, eye dryness sensation, and foreign body sensation) significantly decreased in the bimatoprost 0.01% group from baseline 4.7±3.8 to 2.9±2.3 ( P <0.001) and 2.5±2.0 ( P <0.001) at 6-month and 12-month follow-ups, respectively. Comparison between groups showed differences at both follow-up visits ( P =0.003 and P <0.001, respectively). In vivo confocal microscopy revealed a significant increase in goblet cell density in the bimatoprost 0.01% group compared with the bimatoprost 0.03% group ( P <0.001 at both follow-up visits). All functional parameters and conjunctival hyperemia improved in the bimatoprost 0.01% group at each follow-up visit ( P <0.05) and in comparison with bimatoprost 0.03% ( P <0.05). Conclusion The results of this trial suggest that bimatoprost 0.01% eye drops seem to decrease the ocular discomfort with respect to bimatoprost 0.03% eye drops.