Three-Dimensional Retinal Displacement Before and After Macular Pucker Surgery

Purpose: To measure the coronal and sagittal retinal displacement before and after surgery for epiretinal membranes in InfraRed (IR) horizontal foveal sections and Optical Coherence Tomography (OCT) scans and describe displacement tridimensionality, vison loss and metamorphopsia. Methods: Retrospective series with greater than 6-month average follow-up before and after surgery. Record included best-corrected visual acuity (BCVA), OCT, M-charts, IR retinography. Overall, pre- and post-operative coronal and sagittal retinal displacement across the entire field, concentric circles at 0.5, 1.5 and 4.5mm radii and the central horizontal and vertical meridian were calculated as the optical flow of consecutive images. Results: The study comprised 10 patients (4M, 6F), with 22.7±25.2 months follow-up before surgery and 16.2±7.3 months after. BCVA reduced before surgery (0.15±0.67 logMAR to 0.38±0.85 logMAR; p<0.05) and increased afterwards (0.086±0.61 logMAR; p=0.003). Pre-operative coronal displacement was 30.1±29.1 µm versus 67.0±23.4µm after (p=0.002). Sagittal retinal displacement was 140.9±84.6 µm before surgery, 339.7±172.5 µm after (p=0.017), and 357.6±320.8 µm across the entire follow-up. Pre-operative BCVA decrease correlated to the foveal coronal displacement. Vertical metamorphopsia correlated to the average coronal displacement within 4.5mm radius. Pre- and post-operative sagittal displacement correlated to horizontal metamorphopsia (p=0.006 and p=0.026). Post-operative sagittal displacement correlated with post-operative BCVA (p=0.026) and foveal thickness (p=0.009). Conclusion: The study confirms that post-operative displacement is greater than pre-operative and that sagittal displacement is greater than coronal and correlates with BCVA and metamorphopsia changes.