Meta-analysis of 24-Hour Intraocular Pressure Studies Evaluating the Efficacy of Glaucoma Medicines
Received 8 March 2007; received in revised form 7 September 2007; accepted 2 October 2007. published online 17 December 2007.
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.
Available online: February 20, 2008.
1PRN Pharmaceutical Research Network, LLC, Dallas, Texas.
2Carolina Eye Institute, School of Medicine, University of South Carolina, Columbia, South Carolina.
3Glaucoma Unit, 1st University Department of Ophthalmology, American Hellenic Educational Progressive Association Hospital, Thessaloniki, Greece.
4Charleston Research Company, LLC, Charleston, South Carolina.
Correspondence and reprint requests to William C. Stewart, MD, 7001 LBJ Freeway, Suite 700, Dallas, TX 75244.
Manuscript no. 2007-326.
This meta-analysis was not supported by any public or private funding agency.
ABSTRACT