Abstract / Summary
Background: Histological examination of surgically excised internal limiting membrane (ILM) specimens may provide insights into retinal tissue changes, but their relationship to retinal imaging findings remains unclear. The aim of this study was to correlate retinal imaging findings with histological evidence of retinal tissue components in surgically excised ILM specimens from eyes with idiopathic epiretinal membrane (iERM) or full-thickness macular hole (FTMH).
Methods: This retrospective clinicopathological study included 42 eyes that underwent pars plana vitrectomy with membrane peeling at the Department of Ophthalmology, University Hospital Ulm, Germany, between April 2024 and May 2025: 22 eyes with iERM and 20 with FTMH. Surgically excised tissue from all eyes was examined by transmission electron microscopy (TEM), and clinical data and retinal imaging findings obtained by optical coherence tomography (OCT) were evaluated.
Results: TEM confirmed the ILM in all included eyes. Intact retinal glial cells with ultrastructural features consistent with Müller cells were observed in localized areas of ILM thinning in 3 eyes with iERM but in no eyes with FTMH. Retinal cell fragments were detected in 21 eyes with iERM and 18 eyes with FTMH. Among eyes with iERM, those containing retinal glial cells had a significantly greater mean central macular thickness (CMT, 619 ± 57 µm) than those without retinal glial cells (P = 0.008); all 3 eyes had Stage 3 epiretinal membrane (ERM), ectopic inner foveal layers (EIFL), and central bouquet abnormalities (CBA). OCT findings did not differ according to retinal cell fragment size.
Conclusion: Retinal glial cells adherent to the ILM were identified only in eyes with iERM and were associated with higher-stage ERM, often in areas of ILM thinning. By contrast, retinal cell fragments occurred in both iERM and FTMH. These findings suggest disease-specific differences at the vitreoretinal interface, with stronger and more complex retinal-ILM interactions in iERM that may influence ILM peeling.