A RANDOMIZED, MASKED, CROSSOVER TRIAL OF ACETAZOLAMIDE FOR CYSTOID MACULAR EDEMA IN PATIENTS WITH UVEITIS

Purpose: To study the effect of acetazolamide on cystoid macular edema in patients with uveitis. Methods: Forty patients with chronic interm ediate, posterior, or panuveitis associated cystoid macular edema were randomized into a masked, cross-over trial comparing acetazolamide ve rsus placebo. Patients received an initial 4-week course of either ace tazolamide or placebo (course A) followed by a 4-week washout period. They then received a 4-week course of the opposite study medication (c ourse B). Primary endpoints included area of cystoid macular edema mea sured on late-phase views of fluorescein angiography and visual acuity . Results: Thirty-seven patients completed the trial and were availabl e for analysis; 17 (46%) were randomized to receive acetazolamide and 20 (54%) to receive placebo during course A. Acetazolamide resulted in a 0.5-disc area (25%) decrease in cystoid macular edema over that of placebo (P = 0.01; estimated treatment effect = -0.5 disc areas; 95% c onfidence interval, -0.9 to -0.1). However, there was no statistically significant effect of acetazolamide on visual acuity (P = 0.61; estim ated treatment effect = 0.6 letters; 95% confidence interval, -2 to 3) . Conclusions: A 4-week course of acetazolamide therapy results in a s tatistically significant but small decrease in cystoid macular edema i n patients with chronic uveitis, and does not improve visual acuity. I n contrast to previous studies in the literature, acetazolamide may ha ve a more limited clinical benefit in patients with long-standing cyst oid macular edema associated with chronic uveitis.