Nonpenetrating external trabeculectomy for congenital glaucoma: a retrospective study.

ABSTRACT

OBJECTIVE: To evaluate the results of nonpenetrating external trabeculectomy (NPET) for primary congenital glaucoma (CG). DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Forty-three eyes of 27 consecutive patients with primary CG. METHODS: Initial intent of NPET with intraoperative conversion to trabeculectomy in cases where aqueous humor outflow was deemed insufficient or where Schlemm's canal appeared to be absent. MAIN OUTCOME MEASURES: Intraocular pressure (IOP). Success was defined as an IOP less than 12.5 mmHg at 1 year after the procedure or later, using adjunctive pressure-lowering topical medications whenever needed. RESULTS: Mean initial measures of IOP were 18.8 mmHg. Of the 43 eyes, a total of 13 required conversion to trabeculectomy 9 because of insufficient filtration, 3 because of an apparent absence of Schlemm's canal, and 1 because of accidental perforation. Of these 13 eyes that ultimately underwent trabeculectomy, 11 achieved successful IOP control, 3 in association with topical therapy. In 1 eye, a retinal detachment developed, and in 7 eyes, other complications were observed. Among the 30 remaining eyes that underwent NPET, 2 underwent the procedure twice, and 1 eye underwent the procedure 3 times. Postoperative complications were not noted in this NPET-only group. Mean postoperative IOP was 10.8 mmHg, with final IOP controlled in 28 of the 30 eyes (93%; P<0.0001), occasionally after repeat surgeries and in combination with topical therapy. CONCLUSIONS: Nonpenetrating external trabeculectomy may be considered as an initial procedure for some cases of primary CG. It appears to be an alternative to trabeculectomy with fewer risks of postoperative complications.