[Efficacy of dorzolamide in reducing retinal thickness after photocoagulation in diabetic macular oedema].

Background: Focal photocoagulation interrupts vascular leakage in diabetic macular edema, and allows the retinal pigment epithelium to withdraw fluid that thickens the retina; this mechanism could be enhanced by dorzolamida, a topical carbonic anhydrase inhibitor.

Objective: To determine the efficacy of dorzolamida compared against placebo, in reducing retinal thickness after focal photocoagulation, in eyes with diabetic macular oedema.

Material And Methods: Experimental, comparative, prospective, longitudinal, double blind study in diabetics with focal macular oedema treated with photocoagulation. Treated eyes were randomly assigned three weeks after the procedure to receive dorzolamide (group 1) or placebo (group 2), three times daily during three weeks. Means of visual acuity, center point thickness and macular volume were compared 3 and 6 weeks after photocoagulation within groups (Wilcoxon's t) and between groups (Mann-Whitneys's U).

Results: Sixty-nine eyes form patients aged 58.3 ± 8.3 years; 37 were assigned to group 1 and 42 to group 2. Mean center point thickness changed from 178.4 ± 34μm to 170 ± 29.1μm in group 1 (p = 0.04), and from 179.2 ± 22.4μm to 178.6 ± 20.8μm in group 2 (p = 0.7); mean macular volume changed from 7.63 ± 0.52mm(3) to 7.50 ± 0.50mm(3) in group 1 (p = 0.02) and from 7.82 ± 0.43mm(3) to 7.76 ± 0.42mm(3) in group 2 (p = 0.014).

Conclusions: The efficacy of dorzolamide was higher than that of placebo, to reduce retinal thickness after focal photocoagulation in diabetics with macular oedema.