Prevention of Postoperative Proliferative Vitreoretinopathy in Complex Retinal Detachments with Serial Intravitreal Methotrexate Injections

Background Proliferative vitreoretinopathy (PVR) remains the leading cause of surgical failure after rhegmatogenous retinal detachment (RRD) repair. Methotrexate (MTX) has emerged as a potential antiproliferative adjunct, but evidence is limited. This study evaluated the safety and efficacy of serial intravitreal MTX injections administered throughout the critical postoperative period to prevent the onset of PVR-related redetachment in complex RRD. Methods This retrospective study included 49 eyes undergoing pars plana vitrectomy (PPV) for complex RRD, defined as PVR grade C, recurrent retinal detachment, or detachment associated with penetrating ocular trauma. All eyes received an intraoperative intravitreal MTX injection (400 µg/0.1 mL), followed by biweekly injections for up to 12 postoperative weeks. The primary outcome was single-surgery anatomic success (SSAS) at 12 weeks. Secondary outcomes included final retinal reattachment rate, changes in best-corrected visual acuity (BCVA), and safety outcomes. Results SSAS at 12 weeks was achieved in 85.7% of eyes. After reoperation in selected cases, the final retinal reattachment rate was 93.8%. Mean BCVA improved significantly by 1.29 ± 0.52 logMAR units at 3 months (95% CI, 1.05–1.53; p < 0.001). The most frequent adverse event was conjunctival hyperemia, which resolved after completion of the MTX protocol. No severe ocular or systemic MTX-related adverse events were observed. Conclusions Serial intravitreal MTX injections administered throughout the critical postoperative period demonstrated a favorable safety profile and were associated with high anatomic success rates and meaningful visual improvement in complex RRD.