SEMICONDUCTOR DIODE-LASER TRANSSCLERAL CYCLOPHOTOCOAGULATION VERSUS FILTERING SURGERY WITH MITOMYCIN-C

Both filtering surgery with Mitomycin-C and diode laser cyclophotocoag ulation have proved to be effective alternatives in cases of glaucoma with poor surgical prognosis. The right eyes of 40 pigmented rabbits w ere randomly divided into 2 groups: Mitomycin-C group underwent filter ing surgery with application of 0.4 mg/ml of Mitomycin-C whereas the d iode laser (DL) group received 15 applications of 1.8 J (1800 mW. 1000 ms) distributed in 270 degrees. Mean IOP showed statistical differenc es in two periods between days 3-13 and 45-60 - Mann-Whitney U test - with a higher IOP lowering in the DL group. The comparison of IOP surv ival curves (Log-Rank test) was not significant p = 0.070809. Ocular h ypertension, hyphema and inflammatory signs were higher in the DL grou p, both in short and long term, but in terms of statistical significan ce only ocular hypertension showed differences p = 0.00011717- Fisher exact test. Microscopic examination revealed patent sclerostomies in 6 0% of the MMC group eyes with different grades of fibroblastic prolife ration. In the DL group we observed necrosis of the scleral stroma and of the pigmented and unpigmented ciliary epithelium, with signs of th ermal coagulation of the ciliary stroma and of the stromal vasculature . We must point out that the treatment with laser has proved to be mor e effective although both treatments showed very acceptable IOP loweri ng until 2 months after the surgery.