Adjuvant Anti-VEGF in Vitrectomy for Proliferative Diabetic Retinopathy: Current Evidence, Timing Considerations, and Clinical Implications

This review evaluates the role of intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents as peri-operative adjuvants in pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR). We synthesize current evidence on their use before, during, and after PPV, with emphasis on benefits, limitations, risks, and implications for surgical planning. Randomized trials and meta-analyses consistently show that preoperative anti-VEGF improves surgical safety by reducing intraoperative bleeding, shortening operative time, and lowering rates of early postvitrectomy vitreous hemorrhage, whereas long-term visual acuity benefits remain inconsistent. Intraoperative administration shows weaker and less consistent effects, and postoperative treatment is supported only by small studies, although it may reduce recurrent hemorrhage and anterior segment neovascularization in selected high-risk eyes. Bevacizumab remains the most studied and widely used agent. Newer anti-VEGF agents and higher-dose formulations may offer theoretical advantages, but comparative clinical data specifically in the setting of PDR vitrectomy remain limited. Preoperative anti-VEGF is currently the most evidence-based perioperative strategy, improving intraoperative conditions and early postoperative outcomes without clearly demonstrated durable functional gains. Critical gaps remain in optimal timing, agent selection, and real-world applicability, particularly in resource-limited settings. Large, pragmatic comparative trials and better risk-stratification tools are needed to refine perioperative anti-VEGF protocols in PDR surgery