The correlation between preoperative en face optical coherence tomography and postoperative visual prognoses in idiopathic epiretinal membranes

Purpose: To investigate the correlation between en face optical coherence tomography and improvements in the postoperative prognoses of idiopathic epiretinal membranes. Methods: The medical records of 59 epiretinal membrane patients who had epiretinal membrane peeling between January 2005 and January 2016, and were followed up for > 12 months, were retrospectively reviewed. The preoperative en face images were divided into four sections involving three circular areas (6,000 µm diameter circle, 3,000 μm diameter circle, and 1,000 μm diameter circle) and one square (6,000 × 6,000 μm). The surface area where no epiretinal adhesion was present was quantified by measuring the number of black pixels using image-editing software (Adobe Photoshop CS6, Adobe Systems, San Jose, CA, USA). Then the correlations among the value of black pixels, preoperative and postoperative visual acuities, and central retinal thickness were analyzed. Results: The best-corrected visual acuity (BCVA) was significantly increased after epiretinal membrane peeling (p < 0.001), and the central retinal thickness was significantly decreased (p < 0.001). As the number of black pixels in the circles and the square in the en-face images increased, the postoperative BCVA significantly increased (r = 0.645, p < 0.001; r = 0.590, p < 0.001, respectively). Conclusions: As the nonadhesive surfaces of the epiretinal membrane and the retina in preoperative en face images became wider, the increments of the BCVA after surgery were greater. Therefore, en face optical coherence tomography can be used to predict prognosis after epiretinal membrane peeling.