Abstract
Purpose::
Proliferation of Tenon’s capsule fibroblasts and increased vascularization of the conjunctiva represent major threats to the survival of a glaucoma filtering bleb. Wong, et al studied angiogenesis inhibition of Tenon's capsule fibroblasts. Kahook, et al reported a single case of angiogenesis inhibition with bevacizumab following needle revision of a bleb. This prospective, non-randomized, open-labeled study was undertaken to determine the effect of subconjunctival injections of bevacizumab (Avastin) on fibrosis and vascularization of a filtering bleb.
Methods::
39 eyes with primary open angle glaucoma (POAG), normal tension glaucoma (NTG), or exfoliation syndrome (PXE) had a trabeculectomy, augmented with mitomycin or 5-FU, between November 1997 and October 2006. A subconjunctival injection of Avastin (1.0 mg) was administered proximal to the bleb at the earliest sign of vascularization. If there was still excessive vascularity of the bleb, then the injection was repeated. 23 eyes had one injection, 9 eyes received 2 injections, and 7 eyes received 3 injections. The intraocular pressure (IOP), bleb vascularity, and fibrosis were evaluated weekly until there was stability. Re-evaluations were done monthly.
Results::
31 eyes had a diagnosis of POAG, 5 eyes NTG, and 4 eyes PXE. Mean age was 72 years (range 44-87). Cohort was 34 Caucasians, 4 African-Americans, and 1 Asian. The mean pre-injection IOP was 17.8 Hg + 6.4. One month post-injection, the IOP was 14 mm Hg + 4.5. By the Wilcoxon signed ranks test, this decrease in IOP was statistically significant (p=0.001). The IOP values for months 2-6 were not significantly different from the pre-injection IOP (p=0.153-0.180). The IOP measurement after the first month gradually increased but did not exceed the pre-injection level.24 of the 39 eyes had a detectable decrease in the vascularity of their bleb. There was no evidence of an untoward reaction from the injection of Avastin.
Conclusions::
In this pilot study, 39 eyes with open angle glaucoma (POAG, NTG, PXE) received 1-3 subconjunctival injections of Avastin (1mg) following a trabeculectomy. All IOP measurements after the Avastin injection were equal to or less than their corresponding pre-injection IOP. The one month post-injection IOP was statistically significant (p=0.001). Nearly 2/3 of these eyes had an observable reduction in vascularity of the filtering bleb. There were no complications traceable to the Avastin injection.
Keywords: wound healing • conjunctiva • neovascularization