[Nonpenetrating deep sclerectomy in Brazil: a 3-year retrospective study]

Nonpenetrating deep sclerectomy with external trabeculectomy has been proved to be an effective alternative to classic trabeculectomy for surgical treatment of primary open-angle glaucoma. However, this procedure is not well known nor well accepted among Brazilian ophthalmic surgeons. The aim of this study was to assess the results and success rate of this new filtering surgical procedure in a Brazilian population, with a 3-year follow-up.

One-hundred eleven primary open-angle glaucoma patients underwent deep sclerectomy with external trabeculectomy between 1999 and 2002 (the surgery was performed by two different surgeons using the same procedure). The antimetabolite mitomycin C (0.2 mg/ml) was applied intraoperatively in 80 patients with high surgical risk of failure (80 patients under 45 years of age, black, and having had previous ocular surgery). The postoperative follow-up included assessment of visual acuity, measure of intraocular pressure (IOP), evaluation of the filtration site and optic nerve head using biomicroscopy, and analysis of visual field deficits. Complete success was defined as IOP less than 18 mmHg without medical treatment, while relative success was defined as IOP less than 18 mmHg with medical treatment.

The mean age was 63.7 +/- 13.1 years and 42.3% of patients were black. Mean follow-up was 19.4 months (+/- 11.7). The mean preoperative intraocular pressure was 22.57 +/- 4.92 mmHg, while mean IOP at the last follow-up visit was 14.22 +/- 2.89 mmHg, so that at the end of the follow-up, complete success was 82.7% and relative success was 93.3%. The cumulative probability of complete success was 76% at 3 years. The complication rate was low: intraoperative microperforations (14.4%), conjunctival seidel (12.5%), hyphema (3.8%), flat anterior chamber (2.9%), choroidal detachment (1%), and filtering bleb fibrosis (17.3%).

These results demonstrate that deep nonpenetrating sclerectomy with external trabeculectomy is a safe and efficient filtering procedure that provides satisfactory IOP control with a minimal rate of complications, even in patients with high surgical risk of failure such as the highly mixed Brazilian population. The results suggest that this revolutionary procedure could be used as first-intention treatment in Brazilian glaucomatous patients that do not have access to expensive medical treatment.