PURPOSE: To determine the pathoanatomical alteration of ectopic inner foveal layers (EIFLs) and its relationship to visual recovery after epiretinal membrane peeling surgery. METHODS: Clinical charts and tracked spectral domain optical coherence tomography images of patients diagnosed with Stages 3 and 4 epiretinal membrane were reviewed and analyzed preoperatively and at 3 and 6 months postoperatively. Central macular thickness and EIFL thickness were measured at these time points. The Wilcoxon signed-rank test was used for analysis, and P <
0.05 was considered statistically significant. RESULTS: The study cohort consisted of 54 eyes of 54 patients, 27 of whom were female. The mean age was 69.2 years. The mean Snellen visual acuity improved from 20/50 preoperatively to 20/35 at 3 months ( P <
0.002) and remained 20/35 at 6 months, significantly better than preoperative levels ( P = 0.002). The mean preoperative EIFL thickness was 169.15 µ m and decreased to 95.70 µ m at 3 months ( P = 0.002) and 90.95 µ m at 6 months ( P = 0.02). Similarly, central macular thickness reduced from 510.00 µ m preoperatively to 444.56 µ m at 3 months ( P <
0.002) and 415.50 µ m at 6 months ( P <
0.002). Reduction in EIFL thickness was significantly correlated with improvement in logMAR visual acuity ( P =0.02) 6 months after surgery. CONCLUSION: Epiretinal membrane peeling results in reduced EIFL thickness, restoration of the normal foveal pit structure, and corresponding improvement in visual acuity. Reduction in EIFL thickness is correlated with visual improvement.