PurposeTo analyse the clinical and morphological characteristics of eyes with idiopathic epiretinal membrane (iERM) and foveal herniation (FH).MethodsClinical findings and OCT features of patients with iERM and FH were retrospectively analysed. Primary outcome were changes of the best-corrected-visual-acuity (BCVA) and OCT features from baseline to the last visit. FH patients were divided into two groups based on herniated layers: ganglion cell complex (GCC)-group and sub-GCC-group. Surgical outcome was also assessed.ResultsIn this study, 3882 patients with iERM were screened, of whom 51 (1.3%) were identified with FH. The GCC-group (n= 16) had a better baseline BCVA and thinner central foveal thickness (CFT) in comparison to the sub-GCC-group (n= 35) but without statistical significance (p= 0.330,p= 0.417, respectively). The postoperative BCVA-improvement was similar between the two groups (p= 0.280). Fibrillary surface changes were detected in 42/51 (82.3%) patients, significantly more often in the sub-GCC group (p= 0.020). The baseline BCVA was a predictive factor for the postoperative vision change.ConclusionFH presents with a unique macular morphology in eyes with iERM. Affected eyes experience varying visual disturbances based on the involvement of the inner retinal layers in the foveal herniation. Macular surgery is successful in restoring vision, even though foveal morphology does not fully recover.