Abstract
Purpose: :
Ischemic central retinal vein occlusion (CRVO) is known to cause neovascular glaucoma (NVG). Incidence of NVG in previous reports ranges from 23% to 60%, with a recent study of CRVO natural history from Hayreh reporting NVG incidence of 35%. It is well known that neovascularization is caused by vascular endothelial growth factor (VEGF) from retinal ischemia. Recently, anti-VEGF therapy has become widely used to treat macular edema due to CRVO. This study is to determine if anti-VEGF therapy can reduce the rate of NVG.
Methods: :
This is a retrospective study of ischemic and nonischemic CRVO patients who received anti-VEGF therapy for macular edema. Patient charts were reviewed from November, 2004 to July, 2011. Patients with presenting neovascularization, prior panretinal photocoagulation (PRP), and prior anti-VEGF treatments were excluded. Patients with open angle glaucoma and nonproliferative diabetic retinopathy were included. The primary outcome is the rate of NVG.
Results: :
Thirty eyes of 30 patients with CRVO were included in the study. 17 of 30 eyes were non-ischemic CRVO, and 13 were ischemic CRVO. Of the 17 non-ischemic CRVO eyes, mean presenting visual acuity was 20/80. They received an average of 4.6 anti-VEGF injections (bevacizumab or ranibizumab) over a period of 9.2 months (one injection every 1.9 months) for treatment of cystoid macular edema. Total mean follow up time was 16.9 months. No eye developed NVG, which is consistent with prior reports of nonischemic CRVO. However 1 eye (5.9%) required PRP for neovascularization. Mean visual acuity at last follow up was 20/50. Mean pre-treatment central retinal thickness (CRT) on OCT was 481 microns, and mean post-treatment CRT, 313 microns. Of the 13 ischemic CRVO eyes, mean presenting visual acuity was 20/320. They received an average of 3.5 anti-VEGF injections over a period of 7.4 months (one injection every 2.8 months). Total mean follow up time was 12.2 months. No eye developed NVG, but 3 eyes (23.1%) developed neovascularization requiring PRP. Mean presenting IOP was 15.8 mmHg, and mean final follow up IOP, 14.8. Mean visual acuity at last follow up was 20/800. Mean pre-treatment CRT was 615 microns, and mean post-treatment CRT, 438 microns.
Conclusions: :
Our study shows that anti-VEGF therapy significantly reduced the rate of NVG in ischemic CRVO compared to the previously reported rate in the literature. Thus anti-VEGF therapy may improve the natural course of CRVO, especially in ischemic patients. A larger clinical trial is needed to confirm the results of our study.
Keywords: vascular occlusion/vascular occlusive disease • vascular endothelial growth factor • neovascularization