RESUMEN
The outcome and postoperative complications after trabeculectomies with mitomycin-C application before flap dissection (episcleral) or after flap dissection (scleral bed) were analyzed retrospectively in 82 patients (82 eyes). Thirty-six eyes (43.9%) had an episcleral mitomycin-C application, and 46 (56.1%) had scleral-bed mitomycin-C administration. After a mean follow-up of 10.1 +/- 3.8 months and 9.9 +/- 4.3 months for the episcleral and scleral-bed groups, respectively, complete success (intraocular pressure =21 mm Hg without medications) was achieved in 18 eyes (50%) in the episcleral group and in 43 eyes (93.5%) in the scleral-bed group. Qualified success (intraocular pressure =21 mm Hg with glaucoma medications) was achieved in 10 eyes (27.8%) in the episcleral group and in 8 eyes (17.4%) in the scleral-bed group. Rates of cumulative survival and time of trabeculectomy survival were statistically higher in the scleral bed group (p = 0.002 and 0.0004, respectively). There was a statistically significant difference in the success rates between groups (p = 0.03). The final intraocular pressure was significantly lower in the scleral-bed group (p = 0.015). There were no differences in duration of postoperative follow-up or frequency of complications. Mitomycin-C application after the scleral flap dissection appears to be associated with higher success rates than mitomycin-C application before scleral flap dissection.