Using antimetabolites during nonpenetrating glaucoma surgery helps control IOP

Nonpenetrating glaucoma surgery augmented with small amounts of either mitomycin-C or 5-fluorouracil can provide good IOP control in eyes at high risk of filtering surgery failure, a prospective study shows. Nonpenetrating surgery also eliminates the need for postoperative bleb or suture manipulation, and may have a lower incidence of complications compared with augmented trabeculectomy, the study authors noted.

Peter K. Wishart, FRCOphth, of Royal Liverpool and Broadgreen University Hospital, England, evaluated the long-term efficacy and safety of nonpenetrating glaucoma surgery in 23 eyes of 22 patients, including 15 eyes that had failed previous trabeculectomy and seven eyes with uveitic glaucoma.

In all cases, surgeons augmented the procedure with either 0.04% mitomycin-C (MMC ) or 25 mg/mL 5-fluorouracil (5-FU).

MMC was applied either topically for 1 to 2 minutes or as a 0.04 mL subconjunctival injection into the superior fornix. 5-FU was applied topically for 5 minutes, according to the study.

The researchers found that surgery reduced mean IOP by 41% from 25.8 mm Hg preoperatively to 15.4 mm Hg at final follow-up. In addition, the mean number of glaucoma medications used decreased from three preoperatively to zero, the authors reported.

Overall, 11 eyes achieved an IOP of 21 mm Hg or less without additional medication use and were considered a complete success. Another 10 eyes achieved an IOP of 21 mm Hg or less with the additional use of a topical glaucoma drug; these eyes were considered a qualified success, according to the study.

"Cumulative probability of success was 100% at 2 years, 94% at 3 years and 85% at 4 years," the authors wrote.

Two eyes failed and required additional surgery. However, no patients experienced long-term complications, the authors noted.

The study is published in the May/June issue of Clinical & Experimental Ophthalmology.