Predictive factors for postoperative visual acuity in idiopathic epiretinal membrane: a systematic review

The aim of this study was to review the literature on predictive factors for postoperative visual acuity (VA) in surgery for idiopathic epiretinal membrane (ERM). A systematic review of the literature in the databases of PubMed and Embase was performed. The risk of bias was assessed based on predefined criteria and the results were summarized. In total, 1927 studies were retrieved of which 35 were potentially eligible. Nineteen studies were of adequate quality in terms of bias. Preoperative VA, central foveal thickness (CFT) and inner segment/outer segment (IS/OS) integrity on optical coherence tomography (OCT) were most extensively studied. Other preoperative factors studied were severity of metamorphopsia, several OCT parameters, fundus autofluorescence and multifocal electroretinogram. In the current literature, preoperative VA is the only variable consistently associated with postoperative VA. IS/OS integrity on OCT is probably associated, and the severity of metamorphopsia, cone outer segment tips integrity and fundus autofluorescence are possibly associated with postoperative VA. CFT is not associated with postoperative VA. Further studies with adequate methodological quality are needed to confirm these findings. Therefore, an overall prediction model, including different parameters, is still awaited.