Optimal Timing of Preoperative Anti-VEGF Injection Reduces Long-Term Recurrence After Vitrectomy for Proliferative Diabetic Retinopathy: A Cohort Study

Purpose To determine the impact of preoperative anti-vascular endothelial growth factor (anti-VEGF) injection and its timing on long-term recurrence following vitrectomy for proliferative diabetic retinopathy (PDR). Methods This retrospective cohort study included 367 eyes undergoing pars plana vitrectomy (PPV). Eyes receiving no preoperative anti-VEGF (n = 49) were compared to eyes receiving an injection 4–7 days preoperatively (n = 318). The anti-VEGF group was further analyzed by timing: 4–5 days (n = 107) versus 6–7 days (n = 211) before surgery. The primary outcome was postoperative recurrence (vitreous hemorrhage or retinal detachment), evaluated with Kaplan-Meier and Cox regression analyses. Results Over a mean follow-up of 31 months, the anti-VEGF group had a significantly lower recurrence rate than the no-pretreatment group (29% vs. 49%; P = 0.006) and lower 2-year recurrence-risk (log-rank P = 0.025). Multivariable analysis confirmed preoperative anti-VEGF as an independent protective factor (adjusted hazard ratio [aHR], 0.58; 95% CI, 0.36–0.95). Critically, within the anti-VEGF cohort, an injection window of 4–5 days was associated with significantly lower 2-year recurrence-risk compared to the 6–7 day window (log-rank P = 0.042). Conclusion Preoperative anti-VEGF injection substantially reduces the long-term risk of recurrence after PPV for PDR. Our findings provide the evidence to suggest an optimal therapeutic window of 4–5 days prior to surgery is associated with the best long-term anatomical success.