Clinical factors and predictors for spontaneous separation of epiretinal membranes

Purpose: To investigate the clinical characteristics, imaging features, and predictive factors for spontaneous separation in patients with idiopathic or secondary ERM. Methods: The overall cohort was divided into two subgroups: idiopathic ERM (28 eyes, 56%) and secondary ERM (22 eyes, 44%). Electronic records and multimodal imaging were reviewed. Results: Among the 50 eyes included in this study, the self-separation of ERM occurred over a mean duration of 28.1 ± 25.3 months (median: 25.4 months). Compared with the secondary ERM group, the idiopathic group had a shorter interval to separation (idiopathic vs. secondary, 23.4 vs. 34.1 months, respectively; P =.01) and better vision at diagnosis (logMAR 0.094 vs. 0.224; P =.009) and after separation (logMAR 0.097 vs. 0.188; P =.01). Overall, in both subgroups, spontaneous ERM separation appeared to have been induced by posterior vitreous detachment (PVD) (P <.001). Multivariate analysis revealed that the self-separation interval (odds ratio [OR] 0.936) and IRF (OR 0.049) were significantly associated with complete ERM separation (all P <.05). Additionally, secondary ERM (OR 15.224) and lower initial best-corrected visual acuity (OR 267.589) were significantly associated with improvements in vision after self-separation (all P <.05). Conclusion: The self-separation of ERM appears to be induced by PVD development in most eyes. Owing to the possibility of complete spontaneous separation, surgical membrane peeling may be delayed by up to 28 months in eyes without PVD, regardless of whether the cause is idiopathic or secondary. Patients with secondary ERM may experience favorable visual improvement after self-separation despite having poor vision at diagnosis and IRF on OCT. Key messages: What is known • An epiretinal membrane (ERM), the most prevalent retinal disease in adults, is less understood regarding clinical factors and the accurate mechanism of spontaneous separation. What is new • The separation of ERM appears to be induced by PVD development in most eyes. • Favorable vision outcomes were associated with secondary ERMs and lower initial visual acuity. • Complete ERM separation was associated with a shorter self-resolution interval and the absence of intraretinal fluid (IRF) in OCT imaging.