Suramin to enhance glaucoma filtering procedures: a clinical comparison with mitomycin

Trabeculectomies performed with mitomycin are more likely to be successful, but have an increased rate of complications. We performed a novel approach to enhance the outcome of trabeculectomies using suramin, a substance that inhibits the action of growth factors.

Trabeculectomies were performed in 10 eyes of 10 patients with advanced stages of complicated glaucoma and/or poor visual prognosis in a prospective, consecutive study. For comparison, an equal number of matched controls were selected from surgical cases using mitomycin and another 20 cases without mitomycin. Pre- and post-operative data were evaluated as well as complications and the need for further surgeries.

The follow up was 18 months for the eyes in all groups. Average IOP values decreased from 32.7 mm Hg and 29.5 mm Hg to 19.7 mm Hg and 19.3 mm Hg in the suramin and mitomycin groups. The average number of medications decreased from 2.6 and 2.5 (P <0.86, t-test) to 1.3 and 0.4 (P <0.027) in the suramin- and mitomycin-treated eyes at the last visit. Hypotony following trabeculectomy occurred in 2/10 cases in suramin-treated eyes and 5/10 cases in mitomycin-treated eyes (P <0.18). Hypotony lasting for more than three months occurred in 0/10 suramin-treated eyes and 5/10 mitomycin-treated eyes. Conjunctival dehiscence (2/10), choroidal detachment (4/10), hypotony maculopathy (1/10), and endophthalmitis (1/10) were only noted in mitomycin-treated eyes. Without mitomycin 60% of surgeries performed failed.

In this first study using suramin to inhibit fibrosis following trabeculectomy for complicated cases of glaucoma, it appears that the use of suramin is associated with fewer cases of severe hypotony, choroidal detachment, and severe visual loss as compared to mitomycin, while the success rates seem to be similar.