Background: The purpose of this study was to evaluate the intraocular pressure (IOP)-lowering efficacy and safety of bimatoprost 0.01% or 0.03% as monotherapy in patients treated with latanoprost 0.005% monotherapy who require additional IOP lowering for their ocular hypertension or open-angle glaucoma.
Methods: Two prospective, investigator-masked, randomized, parallel-group, multicenter studies enrolled patients with baseline IOP ≥20 mmHg after ≥30 days of latanoprost 0.005% monotherapy. Patients were randomized to 12 weeks of study treatment (study 1, bimatoprost 0.01% once daily or bimatoprost 0.01% once daily plus brimonidine 0.1% three times daily; study 2, bimatoprost 0.03% once daily or bimatoprost 0.03% once daily plus fixed-combination brimonidine 0.2%/timolol 0.5% twice daily). Patient evaluations at weeks 4 and 12 included IOP at 8 am, 10 am, and 4 pm and safety assessments. Results in the monotherapy study arms (bimatoprost 0.01% or 0.03%) are presented.
Results: Latanoprost-treated baseline mean diurnal IOP (± standard error of the mean) was 22.2±0.3 mmHg and 22.1±0.4 mmHg in the bimatoprost 0.01% and bimatoprost 0.03% treatment arms, respectively (P=0.957). In both treatment arms, mean (± standard error of the mean) reduction in IOP from latanoprost-treated baseline was statistically significant at each time point at both follow-up visits (P<0.001), ranging from 3.7±0.4 (17.0%) mmHg to 4.4±0.4 (19.9%) mmHg with bimatoprost 0.01% and from 2.8±0.5 (12.8%) mmHg to 3.9±0.5 (16.7%) mmHg with bimatoprost 0.03%. Mean percentage IOP reduction from latanoprost-treated baseline was numerically greater with bimatoprost 0.01% than with bimatoprost 0.03% throughout follow-up. The incidence of conjunctival hyperemia of mild or greater severity increased from latanoprost baseline after 12 weeks of treatment only in the bimatoprost 0.03% treatment arm.
Conclusion: Many patients who do not reach their target IOP on latanoprost can achieve additional IOP lowering and maintain monotherapy by replacing latanoprost with bimatoprost. Reductions in IOP from latanoprost baseline were larger with bimatoprost 0.01% than with bimatoprost 0.03%, and bimatoprost 0.01% had a more favorable tolerability profile.
Keywords: bimatoprost; intraocular pressure; latanoprost; monotherapy; prostaglandin; prostamide.