Abstract
Purpose::
To evaluate the 24-hour IOP-lowering efficacy of 2% dorzolamide/0.5% timolol maleate (D/T) after 8 weeks of treatment in patients with open angle glaucoma or ocular hypertension.
Methods::
Randomized, double-masked, parallel group, multicenter clinical trial. After a 6-week timolol run-in, 232 patients with insufficiently controlled IOP (≥22 mm Hg) were randomized to D/T (N=117) or timolol (N=115), administered at 8 AM and 8 PM for 8 weeks. IOP was assessed at randomization (baseline), and weeks 6 and 8. IOP measurements were taken at 6 PM, 8 PM, 10 PM, 2 AM, 6 AM, 8 AM, 10 AM, and 2 PM. The primary outcome variable was the change in IOP from baseline at 8 weeks within the D/T group at all timepoints.
Results::
Baseline characteristics and mean pre-treatment IOPs were similar between groups. After 8 weeks of treatment, IOP was lowered significantly from baseline at all timepoints by D/T (p<0.001 for each timepoint). The mean IOP (%) reductions from baseline ranged from -3.23 mm Hg (13.37%) at 2 AM to -6.75 mm Hg (26.21%) at 10 AM. When compared with timolol alone, D/T had significantly greater IOP reductions at 10 AM [difference = -1.30; 95% CI: -2.14, -0.46; (p=0.003)] and 2 PM [difference = -1.07; 95% CI: -1.94, -0.20; (p=0.016)]. Significant treatment differences were not seen at other timepoints. D/T had significantly lower average daytime IOP (average of 8 AM, 10 AM, 2 PM, 6 PM, 8 PM IOPs) at 8 weeks [-5.88 mm Hg vs. -5.08 mm Hg; difference = -0.80; 95% CI: -1.49, -0.10; (p=0.025)]. There was no treatment difference for the nighttime IOP (average of 10 PM, 2 AM, 6 AM IOPs). After 8 weeks, the mean IOP decrease from baseline ranged from -4.7 mm Hg to -2.5 mm Hg for D/T, and from -3.7 mm Hg to -2.5 mm Hg for timolol. Overall results were similar at 6 weeks.
Conclusions::
D/T significantly reduced IOP from baseline at each of 8 diurnal timepoints over a 24-hour period. IOPs were significantly lower with D/T than timolol alone at 10 AM, 2 PM, and for the average daytime IOP.
Clinical Trial::
www.clinicaltrials.gov NCT00108017
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials