Abstract
Purpose: :
To compare the 24-hour intraocular pressure (IOP) efficacy of the dorzolamide/timolol fixed combination (DTFC) and the brimonidine/timolol fixed combination (BTFC) in primary open-angle glaucoma (POAG).
Methods: :
One eye of 77 POAG patients was included in this prospective, observer-masked, crossover comparison. Following a timolol run-in period for 2 months, all patients underwent a timolol-treated daytime IOP curve with 3 separate IOP measurements performed at 10:00, 12:00 and 14:00. Patients with a mean daytime IOP greater than 18 mm Hg and at least a 20% IOP reduction on timolol were randomized to 2 months of therapy with either DTFC, or BTFC and then were switched to the opposite therapy. This 24-hour IOP study had at least 85% power to identify a 1.0 mm Hg difference between mean 24-hour IOP values assuming a standard deviation of 2.5 mm Hg between treatments.
Results: :
Sixty POAG patients completed the study. The mean 24-hour IOP was significantly reduced with both fixed combinations compared with the mean daytime IOP in the timolol run-in period (P<0.001). When the two fixed combination treatments were compared directly the DTFC demonstrated a lower absolute IOP level for the 24-hour curve compared to the BTFC (mean difference: -0.7 mm Hg, 95 % confidence interval [CI]: -1.0, -0.3, P<0.001). At 2 individual time points DTFC significantly reduced IOP more than BTFC: at 18:00 (-1.0 mm Hg, 95% CI [-1.6,-0.5], p=0.001) and at 02:00 (-0.9 mm Hg, 95% CI[-1.4,-0.5], p=0.001). No significant difference existed for the other time points.
Conclusions: :
Both fixed combinations significantly reduce 24-hour IOP in POAG. DTFC provided significantly better 24-hour efficacy.
Clinical Trial: :
www.clinicaltrials.gov NCT00972257
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials