Characteristics of Spontaneous Idiopathic Epiretinal Membrane Separation in Spectral Domain Optical Coherence Tomography

In Brief Purpose: To investigate the prevalence, characteristics, and visual acuity of spontaneous idiopathic epiretinal membrane (ERM) separations using spectral domain optical coherence tomography. Methods: In a series of 1,248 consecutive eyes with idiopathic ERM, Group I with preexisting posterior vitreous detachment included 1,091 eyes (87.4%) and Group II without preexisting posterior vitreous detachment included 157 eyes (12.6%). Groups IA and IIA included self-resolution cases of ERM from Groups I and II, respectively. Results: The ERM self-separation occurred in 37 eyes (3.0%) for 32.6 ± 11.7 months, with 16 eyes (1.5%) in Group IA and 21 eyes (13.4%) in Group IIA. The mean best-corrected visual acuity (logMAR) improved in Groups IA and IIA by 0.1 (P = 0.013) and 0.06 (P = 0.078), respectively. From tomographic analyses, dominant undulation and retinal nerve fiber layer defects were more frequent in Group IA than Group IIA (P < 0.001 and P = 0.024, respectively). However, the completeness of ERM separation, inner segment/outer segment junction defects, and ERM recurrence were more frequent in Group IIA than Group IA (P = 0.039, P = 0.023 and P = 0.041, respectively). Multivariate analysis for factors related to visual improvement revealed only inner segment/outer segment junction defects as significantly associated (P = 0.025). Conclusion: Different mechanisms underlying the self-resolution of idiopathic ERM lead to distinct tomographic characteristics and may affect the postseparation visual function. Analyses of the prevalence and tomographic characteristics of idiopathic epiretinal membrane self-separation have revealed that different mechanisms (with or without preexisting posterior vitreous detachment) lead to various tomographic properties. These include inner segment/outer segment junction defects, retinal nerve fiber layer loss, and undulation of the retinal surface.