Abstract
Abstract: :
Purpose: To provide additional data in response to queries posed to the authors subsequent to publication of the XLT study. Methods: This randomized, parallel–group study was conducted at 45 U.S. sites over 12 weeks. Previously treated open–angle glaucoma or ocular hypertension patients with an intraocular pressure (IOP) ≥23 mmHg in 1 or 2 eyes after washout received latanoprost, bimatoprost, or travoprost once daily (evening). At baseline and weeks 6 and 12, IOP was measured in triplicate by masked evaluators at 8:00 AM, noon, 4:00 PM, and 8:00 PM. Conjunctival hyperemia was graded by masked investigators before the 8:00 AM IOP measurement at each visit. Patients also were asked whether their red eyes bothered them. Change between baseline and week 12 in 8:00 AM IOP measurements was the primary efficacy outcome. Post–hoc analyses of responder rates, power calculations, and hyperemia gradings were conducted. Results: Responder rates based on percentages of patients achieving either a 15% or 20% reduction in IOP at week 12 were almost identical for all 3 prostaglandin analogs as were proportions of patients reaching specific target IOP levels. At 6 and 12 weeks, no statistically significant difference between treatments was found in the IOP–lowering effect measured at 8:00 AM. Post–hoc power calculations indicated a 91% power to detect a difference of 1.5 mmHg between treatment arms. There was a small but significant increase at all time points after baseline in mean hyperemia scores in the bimatoprost and travoprost treatment groups, with the bimatoprost group having the largest increase and the latanoprost group the smallest increase. Patient responses to hyperemia were consistent with investigator gradings. Conclusions: Mean IOP levels at week 12 were similar across treatment groups at all time points as were the responder rates and proportions of patients reaching specific target pressures. There appears to be no statistical or clinical differences in efficacy among the 3 prostaglandin analogs.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials