NASAL CROWDING AND NASAL TILTING OF THE MACULA AFTER EPIRETINAL MEMBRANE SURGERY.

PURPOSE: To identify postoperative macula deviation after epiretinal membrane surgery and to investigate its clinical effects. METHODS: Patients who underwent idiopathic epiretinal membrane removal and followed up for >12 months were enrolled. Macular deviation was evaluated using disk margin-to-fovea distance, foveal angle, and horizontal and vertical asymmetry of retinal thickness and volume. Horizontal or vertical asymmetry was defined as percentile asymmetry between nasal and temporal quadrants or between superior and inferior quadrants, respectively. The association between macular deviation parameters and best-corrected visual acuity and metamorphopsia were evaluated. Baseline and postoperative parameters were compared depending on epiretinal membrane severity. RESULTS: Data from 102 eyes with a mean follow-up of 21.14 months were analyzed. Disk margin-to-fovea distance and foveal angle decreased with time and horizontal asymmetry of thickness and volume increased with time, showing nasal crowding and nasal tilting. Postoperative changes of disk margin-to-fovea distance and horizontal asymmetry were associated with best-corrected visual acuity. Severe epiretinal membrane eyes showed greater postoperative nasal deviation than mild epiretinal membrane eyes. CONCLUSION: Postoperative nasal crowding and tilting was quantitatively identified. The causative layers for nasal deviation might be the inner retinal layers, as the foveal angle decreased with time. Postoperative disk margin-to-fovea distance shortening and nasal-deviated horizontal asymmetry were correlated with best-corrected visual acuity improvement.