Assessment of macular microvasculature features before and after vitrectomy in the idiopathic macular epiretinal membrane using a grading system: An optical coherence tomography angiography study

PURPOSE To evaluate pre- and postoperative microvasculature features in eyes with different idiopathic macular epiretinal membrane (iERM) classifications using optical coherence tomography angiography (OCTA). METHODS In this retrospective study, 100 eyes with iERM were enrolled; 62 eyes underwent pars plana vitrectomy (PPV). All iERM eyes were evaluated and graded using optical coherence tomography (OCT). According to the thickness of the fovea relative to the surrounding macula from OCT radial line scans, we classified iERM into three grades. Optical coherence tomography angiography (OCTA) was used to measure the foveal avascular zone (FAZ)-related parameters and the superficial and deep capillary plexus layers using 3 × 3 mm scans. Measurements were taken at baseline and 3 months postoperatively. Best corrected visual acuity (BCVA), vessel density (VD), FAZ area, FAZ perimeter (PERIM), acircularity index (AI), and foveal vessel density (FD) were evaluated. RESULTS Idiopathic macular epiretinal membrane (iERM) eyes with a higher grade had a lower FAZ area and perimeter (p