Repeated intravitreal bevacizumab (Avastin®) treatment of persistent new vessels in proliferative diabetic retinopathy after complete panretinal photocoagulation

Abstract

To evaluate the effect of repeated intravitreal injections of bevacizumab (Avastin(®)) in patients with proliferative diabetic retinopathy and persistent new vessels after panretinal photocoagulation. In this prospective study we investigated 11 eyes of 10 diabetic patients with persistent new vessels after previous complete panretinal photocoagulation. Complete ophthalmological examinations were performed at baseline and during monthly follow-up visits until the final follow-up at 6 months. Colour fundus photography, fluorescein angiography (FA) and macular optical coherence tomography (OCT) were performed. The area of leakage (mm²) found in the FA was used to demonstrate the effect of bevacizumab on retinal new vessels. Patients received 1.0 mg of intravitreal bevacizumab at baseline and at each of the monthly follow-up visits when reappearance of retinal new vessels was documented. At the 1-week follow-up visit, 73% of the treated eyes showed complete regression of retinal new vessels. Eight eyes were assigned to retreatments at the 3-month follow-up because of the reappearance of retinal new vessels. After 6 months, 36% of the eyes were found to have reappearance of retinal new vessels. The retreatment rate was 1.9 ± 0.7 and the mean interval to retreatment was 2.9 ± 1.0 months. The mean leakage area decreased from 7.2 ± 2.6 mm² at baseline to 1.2 ± 0.9 mm² at the final follow-up visit. BCVA increased from 59.2 ± 14.6 Early Treatment Diabetic Retinopathy Study (ETDRS) score (range 40-80) to 70.7 ± 8.5 at the final visit (p = 0.017). Intravitreal bevacizumab led to a significant reduction of retinal new vessels for a mean period of 2.9 months. A 3-monthly retreatment regime might be a valid method to control retinal new vessels in diabetic patients with persistent new vessels.