Meta-analysis of 24-hour intraocular pressure studies evaluating the efficacy of glaucoma medicines

Purpose: To evaluate efficacy and safety data of currently available ocular hypotensive medicines derived from 24-hour studies, of similar design, in patients with primary open-angle glaucoma (POAG), exfoliative glaucoma, or ocular hypertension (OH). Design: Meta-analysis of published articles evaluating patients with POAG, exfoliative glaucoma, or OH. Methods: We included articles that were randomized, prospective, single- or double-masked, comparative studies of ocular hypotensive therapies over 24 hours. Each article selected contained an untreated baseline, >= 4-week treatment period, >= 20 patients per treatment arm, and >= 6 time points not spaced >5 hours apart and used Goldmann applanation or Tonopen tonometry (supine measurements) to measure intraocular pressure (IOP). Main Outcome Measure: Twenty-four-hour IOP efficacy. Results: This analysis included 864 separate 24-hour treatment curves from 386 patients in 28 treatment arms from 11 studies. A statistical difference in the mean diurnal pressure decrease existed between monotherapy treatments for POAG/OH patients, with bimatoprost (29%) and travoprost (27%) showing the greatest 24-hour reduction (P = 0.026). Timolol 0.5% was less effective than latanoprost (24% vs. 19% reduction) but decreased the pressure at each night time point (P = 0.0003). Dorzolamide showed a 19% 24-hour pressure reduction and brimonidine 0.2% a 14% one. In exfoliative glaucoma patients, latanoprost and travoprost showed higher baseline and treatment pressures, although the pressure reductions (29% and 31 %, respectively) were greater generally than observed with POAG/OH. An evening-dosed latanoprost/timolol fixed combination reduced the pressure 33%, and the dorzolamide/timolol fixed combination (DTFC), 26%. However, the power to detect a difference for this specific comparison was probably low, due to the limited number of patients (n = 20) in the DTFC group. A statistical difference between evening-dosed (24%) and morning-dosed (18%) latanoprost (P<0.0001) was noted, but not between evening (27%) and morning (26%) travoprost (P = 0.074). The mean reduction of night time points was statistically lower than day time points for latanoprost (P = 0.031), timolol (P = 0.032), and brimonidine (P = 0.050), but not for dorzolamide. Dorzolamide (P = 0.60), travoprost (P = 0.064), and bimatoprost (P = 0.057) did not demonstrate nighttime pressures lower than daytime ones. The mean reduction of night time points was statistically lower than that of day time points for latanoprost (P = 0.031), timolol (P = 0.032), and brimonidine (P = 0.050), but not for dorzolamide (P = 0.60), bimatoprost (P = 0.057), travoprost (P = 0.064). Conclusions: Similar relative efficacies generally exist in various classes of ocular hypotensive agents during night and day hours.