gms | German Medical Science

Purpose: To describe immunocytochemical and ultrastructural characteristics of vitreomacular traction associated with epiretinal membranes at the vitreomacular interface in non-neovascular age-related macular degeneration (AMD), to correlate with optical coherence tomography (OCT) findings and clinical data.

Methods: Epiretinal membrane (ERM) specimens were removed sequentially with the internal limiting membrane (ILM) from 30 eyes of 29 patients for vitreomacular traction with non-neovascular AMD during standard vitrectomy. Specimens were processed for immunocytochemical staining of epiretinal cells and extracellular matrix components. Ultrastructural analysis was performed using transmission electron microscopy. Spectral-Domain OCT images and patient charts were evaluated in retrospect.

Results: Immunocytochemistry revealed myofibroblasts and hyalocytes as predominant cell types Ultrastructural analysis demonstrated hyalocytes embedded in thick vitreous cortex collagen. Myo-fibroblasts with contractive properties were observed to tighten the ILM and vitreous collagen strands with immunopositive staining for collagen type I, II and III. Retinal pigment epithelial cells were not detected. Preoperative mean VA (LogMAR) was 0.54 ± 0.22 and significantly improved after a mean follow-up period of 12.4 months to 0.33 ± 0.21 (P < 0.001). None of the eyes showed conversion to neovascular AMD during follow-up. Regression of drusen was found in 70% of eyes.

Conclusions: Epiretinal membranes at the vitreomacular interface in non-neovascular AMD predominantly constitute of hyalocytes and myofibroblasts with contractive properties. Vitreous collagen is firmly attached to the ILM and interspersed with epiretinal cells. Release of traction by ERM removal and ILM peeling resulted in functional and anatomical improvement with a regression of drusen in the majority of eyes.