Intravitreal methotrexate infusion for prophylaxis of proliferative vitreoretinopathy after pars plana vitrectomy for rhegmatogenous retinal detachment

Abstract Background: Proliferative vitreoretinopathy (PVR) is the leading cause of recurrent retinal detachment after surgical repair of rhegmatogenous retinal detachment (RRD). Our study aimed to assess the efficacy and safety of intravitreal methotrexate infusion (IMI) for the prevention of PVR after pars plana vitrectomy (PPV) in eyes with RRD. Methods: This prospective comparative interventional study was conducted from September ۲۰۲۰ to November ۲۰۲۱ at Ain Shams University Hospitals, Egypt. We recruited a consecutive, non-randomized sample of ۴۷ eyes of ۴۷ patients with RRD undergoing PPV. Participants were allocated to a control group or an intervention group that received IMI during surgery. Each group was subdivided into subgroups of eyes at high-risk of developing PVR and eyes with established preoperative PVR grade C. Outcome measures at the ۳-month postoperative follow-up were the rate of retinal attachment, incidence of PVR, reoperation rate to flatten the retina, and changes in the retina and/or optic nerve function as assessed by full-field electroretinogram and flash visual evoked potential. Results: Data from ۴۷ eyes (۲۳ and ۲۴ eyes in the intervention and control groups, respectively) were evaluated. Subgroups IA, IB, and IIB each included ۱۲ eyes, subgroup IIA included ۱۱ eyes, and all subgroups had comparable sex ratios and age distributions. Postoperative PVR at ۱ month and between ۱ and ۳ months was present in ۱۳% and ۴% of eyes in the intervention group, respectively. Reoperation to flatten the retina was required in ۲ (۹%) eyes in the intervention group, while ۲۲ eyes (۹۶%) had complete flattening of the retina at ۳ months. No significant differences were found between the study groups and the corresponding subgroups regarding the outcome measures (all P > ۰.۰۵). No adverse events attributable to IMI were detected up to ۳ months postoperatively. Conclusions: Although IMI was safe for intraocular use in eyes with RRD and PVR grade C or a high risk of developing PVR, it did not affect the anatomical success rate or development of PVR up to ۳ months after PPV. Further multicenter randomized clinical trials with longer follow-up periods and larger sample sizes are needed to verify these preliminary outcomes.