Outcome of a Single Intravitreal Bevacizumab Injection on the Visual Acuity and Course of Pars Plana Vitrectomy in Proliferative Diabetic Retinopathy

Abstract

Abstract Purpose: To evaluate the effect of a single intravitreal 1.25 mg/0.05 ml bevacizumab (IVB) (Avastin, Genentech) injection on the visual outcome and both intraoperative and postoperative course of pars plana vitrectomy (PPV) in proliferative diabetic retinopathy. Study Design: Prospective case-control interventional comparative study. Methods: One hundred patients (100 eyes) were divided into two groups: Group I had undergone PPV with preoperactive IVB (50 patients), and Group II had undergone PPV without IVB (50 patients). Best corrected visual acuity (BCVA), intraoperative and postoperative complications were compared between both groups. Patients were followed-up for one year. Results: After one year, there was a highly statistically significant difference in the mean BCVA, as it was (0.146 ± 0.103) in Group I and 0.069 ± 0.049 in Group II with (p < 0.001), while mean bleeding frequency in Group I was 0.7 ± 0.78 times/case with range between 0 and 2 bleeding attacks/case and mean bleeding frequency in Group II was 3.12 ± 1.31times/case with range between 3 and 6 bleeding attacks/case and the difference was statistically significant as (p < 0.001). Diathermy was used in Group I in 15 patients only with mean frequency of 0.3 ± 0.46 times/case with range between 0 and 1 attack/case; while diathermy was used in all cases in Group II with mean frequency of 2.4 ± 1.06 times/case with range between 1 to 4 times/case and this difference was also statistically significant as p < 0.001. Postoperative vitreous hemorrhage developed in 3 eyes (6%) in Group I and 15 eyes (30%) in Group II and this difference was statistically significant (p < 0.003). All the other intraoperative and postoperative complications were reduced in Group I, but with no statistically significant difference between both groups. Conclusions: The use of intravitreal bevacizumab before pars plana vitrectomy is beneficial in improving visual outcome, minimizing the incidence of intraoperative bleeding and reducing the need for intraoperative diathermy.