Interferon Alpha-2a for Proliferative Diabetic Retinopathy after Complete Laser Panretinal Photocoagulation Treatment

BACKGROUND AND OBJECTIVE: The aim of this study was to investigate the effect of interferon alpha-2a, an angiogenesis inhibitor, on eyes with active neovascularization after complete laser panretinal photocoagulation treatment. PATIENTS AND METHODS: Eight patients with active neovascularization persisting for 6 months or more after completion of full panretinal photocoagulation were included in the study. All patients were treated with subcutaneous injections of 6 million international units of interferon alpha-2a, 3 times a week, for an average period of 10 months. Visual acuity, contrast sensitivity, blood tests, fundus photographs, fluorescein angiography, and physical examination were performed periodically. The main outcome measures were visual acuity and extent of neovascularization as assessed by fundus photography and fluorescein angiography. RESULTS: The 5 men and 3 women (mean age, 60 years) had a mean duration of diabetes of 19 years. The average study follow-up was 42.2 ± 8.7 weeks. Visual acuity and extent of neovascularization improved or remained stable in 7 patients. In none of the patients was there progression of neovascularization, but in 1 patient it could not be assessed due to vitreous hemorrhage. Most patients had malaise during the first weeks of treatment, but none of the patients suffered from nonreversible side effects associated with interferon alpha-2a. CONCLUSION: This pilot study provides evidence that interferon alpha-2a might have a role in the regression of proliferative diabetic retinopathy and that further investigation is warranted.