Abstract:AIM: To determine the rate and possible contributors for post-pars plana vitrectomy (PPV) epiretinal membrane (ERM) in patients treated for rhegmatogenous retinal detachment (RRD). METHODS: This prospective, nonrandomized study comprised 47 consecutive patients (47 eyes) with acute RRD treated with 23 G post-PPV. All participants were followed prospectively for 6mo for the development of ERM using spectral domain optical coherence tomography. Preoperative and intraoperative data were collected by questionnaires to surgeons. Main outcome measure was the percentage of the ERM formation following post-PPV for RRD. RESULTS: ERM developed postoperatively in 23 eyes (48.9%), none necessitated surgical removal. There was a statistically significant difference between patients with and without ERM postoperatively in preoperative best corrected visual acuity (median logMAR 1.9 vs 0.3, respectively; P=0.003) rate of macula-off (69.6% vs 37.5%, respectively, P=0.028), and rate of ≥5 cryo-applications (55.6% and 18.8%, respectively, P=0.039). ERM developed mainly between the 1st and 3rd months of follow-up. Macula-off status increased the risk of ERM, with the odds ratio of 3.81 (P=0.031). CONCLUSION: ERM is a frequent post RRD finding, and its development is associated with macula-off RRD.