Aim: To study the effect of acetazolamide on cystoid macular oedema (CMO) in patients with Behcet's disease.
Patients and methods: A total of 67 eyes of 35 Behcet's patients with chronic, but well-controlled uveitis, and CMO were randomised into a double-masked, crossover trial comparing the effect of acetazolamide vs placebo. The patients received an initial 4-week course of either 250 mg acetazolamide twice daily (b.i.d.) or placebo, followed by a 4-week washout period. They then received a 4-week course of the reverse study medication. An improvement in visual acuity and fundus fluorescein angiographic findings was assessed.
Results: In total, 29 patients (55 eyes) completed the trial and were available for analysis. Of the 29, 16 men and 13 were women. The age range was 13-50 years (mean 33.6 years). Patients on acetazolamide showed a slightly better improvement of angiographic signs (at least by one grade improvement) over that of placebo (12 vs five eyes). They also had less deterioration of angiographic signs over that of placebo (three vs seven eyes). However, these findings were not statistically significant (P=0.99). Acetazolamide had no statistically significant effect (P=0.53) on the improvement of visual acuity of patients over that of placebo (13 vs eight eyes), nor on the deterioration of visual acuity (three vs 11 eyes).
Conclusion: Despite seemingly favourable results, the 4-week course of acetazolamide (250 mg b.i.d.) has no statistically significant effect on the improvement of the visual acuity and the fluorescein angiographic findings in Behcet's patients with CMO.