Paravascular abnormalities in eyes with idiopathic epiretinal membrane

The purpose was to investigate the paravascular abnormalities (PVA) around the retinal vascular arcades and their post-operative evolution in eyes with epiretinal membranes (ERM). This is an observational case series. Fifty-seven eyes of 55 patients with concurrent PVA and ERM were studied (study group). Forty-one eyes in 41 patients with ERM but no PVA served as controls. Multiple optical coherence tomography (OCT) scans were made along the upper and lower arcades and across the fovea in each patient. Serial fundus photography and OCT scans were performed in eyes receiving an operation. All surgeries were performed by one surgeon. The incidence and location of paravascular retinal cysts, deep cystic spaces underneath the vessels, and paravascular retinal defects, as well as vitreoretinal interface changes, were determined and correlated with macular thickness. In the study group, paravascular retinal cysts were detected in 57 eyes (100 %), deep cystic spaces in nine eyes (15.8 %), and paravascular lamellar holes in 31 eyes (54.4 %). No case had a full-thickness hole. ERM adhesion to the PVA was noted in 16 eyes (28.1 %) and internal limiting membrane (ILM) changes over the PVA in 22 eyes (38.6 %). Compared with the control, the study group had significantly increased macular thickness. PVA, except lamellar holes, disappeared or decrease in severity after ERM and ILM removal surgery. Different types of PVA are relatively common in eyes with ERM. Our findings suggest that PVA may develop secondary to ERM-induced macular thickening. Except for lamellar holes, most lesions decrease following an operation.