Association of Preoperative Optical Coherence Tomography Markers with Residual Inner Limiting Membrane in Epiretinal Membrane Peeling

PURPOSE: To identify preoperative markers on spectral domain optical coherence tomography (SD-OCT) for residual inner limiting membrane (ILM) in epiretinal membrane (ERM) peeling. METHODS: In this retrospective case series the preoperative SD-OCTs from 119 eyes of 119 consecutive patients who underwent surgery for idiopathic ERM by a single surgeon were evaluated for markers predisposing for ILM persistence after ERM removal. ILM persistence was determined via intraoperative indocyanine green staining. The main outcome measures were correlation of central foveal thickness (CFT), ERM thickness, extent of elevated ERM and retinal folding, intraretinal cysts, and discontinuation of the ERM, with ILM persistence after ERM peeling. RESULTS: The persistence of the ILM was found in 50.4% (n = 60). After Bonferroni correction for multiple testing, a greater extent of elevated ERM and thicker ERMs were associated with persistence of the ILM (p<0.005). The other parameters showed no statistically significant correlations with the persistence of the ILM (p≥0.005). CONCLUSION: Residual ILM can be found in nearly half of the eyes after ERM peeling. A loose connection between the ERM and the retinal surface predisposes for ILM persistence. Preoperative SD-OCT is helpful in identifying risk markers for the persistence of the ILM in ERM surgery.