A randomized, investigator-masked comparison of diurnal responder rates with bimatoprost and latanoprost in the lowering of intraocular pressure.

In glaucoma and ocular hypertension, clinically relevant intraocular pressure lowering due to a new medication is frequently defined as at least a 15% or 20% reduction from baseline intraocular pressure. This report compares the percentages of treated patients achieving such reductions in intraocular pressure after 6 months of treatment with bimatoprost or latanoprost. In the previously published study (Noecker et al: A six-month randomized clinical trial comparing the intraocular pressure-lowering efficacy of bimatoprost and latanoprost in patients with ocular hypertension or glaucoma. Am J Ophthalmol 135:55-63, 2003), patients with glaucoma or ocular hypertension were randomly assigned to once-daily treatment with bimatoprost 0.03% (n=133) or latanoprost 0.005% (n=136), after washout of any previous glaucoma medications. The primary outcome measure of that study was mean change from baseline intraocular pressure. The secondary, post hoc analysis presented here compares the diurnal and long-term responder rates observed with bimatoprost and latanoprost patients. Diurnal responders were defined as patients who achieved at least a 15% or 20% reduction from baseline intraocular pressure at each of the three timepoints (8 am, 12 pm, and 4 pm) on a given visit. At week 1 and months 1, 3, and 6, in the bimatoprost group, 70.7-81.2% of patients achieved at least a 15% reduction in IOP at each timepoint, and 57.9-68.4% achieved at least a 20% reduction. Significantly fewer patients receiving latanoprost achieved a 15% or a 20% decrease in IOP at each timepoint: 48.5-61.8% of patients achieved at least a 15% decrease and 36.0-47.1% achieved at least a 20% decrease. (P< or =.007). The data presented here suggest that patients using bimatoprost are more likely than patients using latanoprost to achieve intraocular pressure reductions of at least 15% or 20% from baseline throughout the day.