Background: The aim of the study was to investigate the intraoperative characteristics of the posterior vitreous cortex in patients with epiretinal membranes.
Method: Fifteen eyes of 15 patients with an idiopathic epiretinal membrane that had no posterior vitreous detachment (PVD) on both slit-lamp biomicroscopy and B-scan ultrasound examination were enrolled in this study. During vitrectomy, the relationship between the posterior vitreous cortex and the epiretinal membrane was observed when PVD was created using triamcinolone acetonide.
Results: Three patterns were observed: (A) seven eyes (47%) showed a round defect in the posterior vitreous cortex after surgical PVD, leaving an epiretinal membrane on the macula, (B) three eyes (20%) showed a complete detachment of the vitreous cortex along with the epiretinal membrane, and (C) five eyes (33%) showed a detachment of the posterior vitreous cortex without a round defect, leaving an epiretinal membrane on the macula. Four of five eyes in group C had a discrete linear signal over the macular area on optical coherence tomography before surgery.
Conclusion: The finding that during surgery the posterior vitreous cortex can split into lamellae supports the hypothesis that epiretinal membranes are the result of anomalous PVD with vitreoschisis, leaving the outermost layer of posterior vitreous cortex attached to the macula.