An augmented trabeculectomy for neovascular glaucoma

Abstract

Background and objective: To report on a new surgical technique for neovascular glaucoma (NVG) in patients with proliferative diabetic retinopathy or retinal vein occlusion.

Patients and methods: 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.

Results: 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.

Conclusion: 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.