An Augmented Trabeculectomy for Neovascular Glaucoma

Abstract

To report on a new surgical technique for neovascular glaucoma (NVG) in patients with proliferative diabetic retinopathy or retinal vein occlusion. Fourteen eyes of 13 patients underwent an augmented trabeculectomy for NVG between January 2000 and February 2003. The augmented trabeculectomy consisted of a 7 × 5 × 5 mm trapezoidal scleral flap, a 6 × 4 × 4 mm deep sclerectomy, application of mitomycin C (MMC) 0.2% for 3 minutes in the deep scleral bed, a 2 × 1 mm trabeculectomy, and the use of a hydrophilic implant (T-flux; Carl Zeiss Meditec, Wetzlar, Germany) as a wick drain connecting the posterior chamber and the deep sclerectomy via a peripheral iridectomy. Whenever the intraocular pressure (IOP) rose above 20 mm Hg, the site of filtration was surgically revised and MMC 0.2% was reapplied in the deep scleral bed. IOP decreased from a mean of 38.7 ± 5.2 mm Hg preoperatively to a mean of 17.3 ± 5.2 mm Hg postoperatively after a mean follow-up of 32 ± 12 months (P = .001, Wilcoxon signed-ranked test, two related samples). Mean visual acuity improved from 20/350 to 20/170 (P = .034). Seven eyes (50%) needed one surgical revision and one eye (7%) needed two surgical revisions within 3 months from the first operation to maintain an IOP of less than 21 mm Hg. The modified trabeculectomy augmented by MMC 0.2% and the use of the T-flux as a wick drain can provide adequate IOP control in NVG caused by proliferative diabetic retinopathy or retinal vein occlusion. To maintain an IOP of less than 21 mm Hg without anti-glaucoma medications, surgical revisions of the filtration site are necessary in at least 50% of patients.