Purpose: To evaluate the additional therapeutic effect of single intravitreal bevacizumab injection on standard laser treatment in the management of proliferative diabetic retinopathy.
Methods: A prospective, fellow-eye sham controlled clinical trial was conducted on 80 eyes of 40 high-risk characteristic proliferative diabetic retinopathy type II diabetics. All cases received standard laser treatment according to Early Treatment Diabetic Retinopathy Study protocol. Avastin-assigned eyes received 1.25 mg intravitreal bevacizumab (Genentech Inc., San Francisco, CA) on the first session of their laser treatments. Fluorescein angiography was performed at baseline and at weeks 6 and 16, and proliferative diabetic retinopathy regression was evaluated in a masked fashion.
Results: The median age was 52 years (range: 39-68) and 30% of the participants were male. All patients were followed for 16 weeks. A total of 87.5% of Avastin-injected eyes and 25% of sham group showed complete regression at week 6 of follow-up (p<0.005). However, at week 16, PDR recurred in a sizable number of the Avastin-treated eyes, and the complete regression rate in the two groups became identical (25%; p=1.000); partial regression rates were 70% vs 65%. In the subgroup of Avastin-treated eyes, multivariate analysis identified hemoglobin A1c as the strongest predictor of proliferative diabetic retinopathy recurrence (p=0.033).
Conclusions: Intravitreal bevacizumab remarkably augmented the short-term response to scatter panretinal laser photocoagulation in high-risk characteristic proliferative diabetic retinopathy but the effect was short-lived, as many of the eyes showed rapid recurrence. Alternative dosing (multiple and/or periodic intravitreal Avastin injections) is recommended for further evaluation.