Incidence and Risk Factors of Epiretinal Membrane Formation After Pars Plana Vitrectomy for Primary Rhegmatogenous Retinal Detachment

Purpose: Formation of an epiretinal membrane (ERM) is a major cause of decreased visual acuity after surgical treatment of rhegmatogenous retinal detachment (RRD).This study analyzed the incidence and risk factors of ERM formation after primary vitrectomy of RRD.Methods: This retrospective and interventional case series included 217 eyes from 217 patients who underwent vitrectomy by a single surgeon to repair a primary RRD from March 2012 to August 2022.Eyes were excluded if they underwent combination surgery of scleral buckling and vitrectomy, had a history of scleral buckling or vitrectomy, or had a prior ERM.Eyes with retinal detachment caused by a macular hole were also excluded.Data on demographics, ocular status, and intraoperative techniques were collected.At 1 week and 1, 3, and 6 months after surgery, fundus photography and macular optical coherence tomography were used to investigate the status of retinal reattachment and development of an ERM over the macula.Additional ERM surgery was performed in patients with ERM formation if there were symptoms such as visual disturbance or metamorphopsia.Results: Of the 217 eyes, a macular ERM occurred in 42 eyes (19.3%).Additional ERM surgery was performed in 18 eyes (8.3%) of patients with ERM formation.The ERM group was significantly older (p = 0.020) and had a greater proportion of patients with large retinal break before RRD surgery (p < 0.001) than the non-ERM group.The additional ERM surgery group had a significantly greater proportion of patients with large retinal break before RRD surgery (p = 0.023) than the non-ERM group.There was no significant difference in sex, macular detachment, smoking history, diabetes mellitus history, high myopia, intraoperative techniques or postoperative vitreous hemorrhage between the non-ERM group and the ERM group or the additional ERM surgery group.Conclusions: Patients who underwent vitrectomy to repair a RRD should be carefully monitored, especially in older patients or cases with a large retinal break.