A factor for predicting simultaneous internal limiting membrane peeling during epiretinal membrane removal: swept-source optical coherence tomography-based evaluation of epiretinal membrane adhesion to the retina

Purpose To investigate preoperative factors associated with simultaneous internal limiting membrane (ILM) peeling during epiretinal membrane (ERM) removal. Study design Observational cross-sectional study. Methods We retrospectively reviewed 60 eyes with idiopathic ERM that underwent vitrectomy. The gap between the ERM and ILM was visualized using en face optical coherence tomography. The depth and width of the ERM–ILM gap at the initiation site of ERM removal were measured, and the relationship between preoperative factors including these parameters and simultaneous ILM peeling during ERM removal was investigated. Results The ILM was simultaneously peeled during ERM removal in 30 eyes, but not in the other 30 eyes. Age was significantly higher (P = 0.017) and the width of the ERM–ILM gap was significantly smaller (P < 0.001) in the simultaneous ILM peeling (+) group than in the simultaneous ILM peeling (–) group. Multivariate logistic regression analysis confirmed the width of the ERM–ILM gap as a significant negative predictor for simultaneous ILM peeling (odds ratio, 0.992; 95% confidence interval, 0.986–0.997; P = 0.003). Receiver operating characteristic curve analysis of the width of the ERM–ILM gap revealed that the optimal cutoff for predicting simultaneous ILM peeling was 187.1 µm. Conclusion The small width of the ERM–ILM gap at the initiation site of ERM removal was significantly associated with simultaneous ILM peeling, indicating that the adhesion strength between the ERM and ILM at the initial ERM grasping site determines whether simultaneous ILM peeling will occur during ERM removal.