Influence of retinal vessel printings on metamorphopsia and retinal architectural abnormalities in eyes with idiopathic macular epiretinal membrane

PURPOSE. To investigate whether the presence of retinal vessel printings (RVPs) in eyes having idiopathic epiretinal membrane (ERM) is associated with a higher degree of metamorphopsia or with more prominent abnormalities in the retinal architecture compared with eyes not having RVPs. METHODS. A cross-sectional study of 36 eyes in 36 patients was conducted. The patients were divided into two groups (18 eyes per group) on the basis of the presence or absence of RVPs on fundus autofluorescence (FAF) imaging. Metamorphopsia was assessed using M-CHARTS. The optical coherence tomography (OCT) and FAF images were recorded using the Spectralis HRAþOCT. The macula was divided into 15 squares, and the areas between the displaced retinal vessels and the corresponding RVPs were calculated. RESULTS. Vertical, horizontal, and average metamorphopsia scores did not differ between the two groups. However, only two patients in the group with RVPs had an average metamorphopsia score of 0.6 or less versus nine patients in the group without RVPs (P ¼ 0.029). There was no correlation between the area of displacement and vertical (P ¼ 0.44), horizontal (P ¼ 0.8), or average (P ¼ 0.38) metamorphopsia scores. The eyes with RVPs manifested a higher degree of irregularity of the external limiting membrane (ELM) and the photoreceptor inner segment/outer segment (IS/OS) lines (P ¼ 0.042 and P ¼ 0.014, respectively). The presence of RVPs was the only independent variable associated with an average metamorphopsia score of 0.6 or higher. CONCLUSIONS. The presence of RVPs in eyes with idiopathic macular ERM is usually associated with an average metamorphopsia score of 0.6 or higher using M-CHARTS and with a higher degree of irregularity of the ELM and IS/OS lines at the fovea.