Abstract
Purpose: :
Although bevacizumab, a humanized monoclonal anti-VEGF antibody, is effective in treating ocular neovascularization, there are some concerns that blocking VEGF might be harmful for the retinal neurons. The purpose of this study was to evaluate the effect of vitrectomy with preoperative intravitreal bevacizumab (IVB) for proliferative diabetic retinopathy (PDR) on visual function.
Methods: :
Eighteen eyes of 15 patients (9 men and 6 women) with PDR that visited the Nagoya University Hospital from November 2006 to October 2008 were treated with IVB (1.25 mg/0.05 ml), 5-7 days before vitrectomy. The protocol was approved by the Institutional Review Board of Nagoya University, and a written informed consent was obtained from each patient. The eyes had vasculary active proliferative membrane, but the vitreous hemorrhage was not dense and the fundus was easily visible. The mean age of the patients was 42.9 ± 2.9 (27-59) years, and the mean follow-up period was 9.7 ± 1.7 (1-24) months after vitrectomy. The visual acuity (VA), visual fields by Goldmann perimeter, and electroretinography (ERG) were measured before the IVB, before the vitrectomy, and after the vitrectomy. VF area was measured using computer software (Scion Image).
Results: :
After the IVB, there was no significant change in the VA, visual fields (VFs), and the amplitudes of the a- (from 240.7 µV to 260.6 µV) and b-waves (from 200.3 µV to 250.5 µV) of the ERGs. The VA was improved by the surgery from 20/500 to 20/100. Even in cases with proliferative membrane covering the optic disc, there was no significant decrease change in the VF area after the surgery (from 8135.9 degrees2 to 8018.0 degrees2). No significant ocular or systemic adverse events were observed.
Conclusions: :
The improvement of the VA in eyes with PDR was obtained after IVB-assisted vitrectomy without significant adverse events. There was no deterioration of the VF, even in the group with proliferative membrane covering the optic disc. Although this study has some limitations, e.g., small number of patients and its retrospective nature, we conclude that IVB is most likely not harmful for retinal neurons if bevacizumab is washed out in less than one week. In addition, preoperative IVB made the surgery much easier by decreasing the activity of new vessels, and appears to be not detrimental for retinal neurons in eyes with PDR.
Keywords: diabetic retinopathy • vitreoretinal surgery • visual fields