Pathogenesis of Ectopic Inner Foveal Layers (EIFL) and Its Impact on Visual Recovery after Epiretinal Membrane Peeling.

Abstract

Purpose: To determine the pathoanatomical alteration of ectopic inner foveal layers (EIFL) and its relationship to visual recovery after epiretinal membrane (ERM) peeling surgery.

Methods: Clinical charts and tracked spectral-domain optical coherence tomography images of patients diagnosed with stage 3 and 4 ERM were reviewed and analyzed preoperatively and at 3 and 6 months postoperatively. Central macular thickness (CMT) and EIFL thickness were measured at these time points. 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 VA improved from 20/50 preoperatively to 20/35 at 3 months (P<0.001) and remained 20/35 at 6 months, significantly better than preoperative levels (P=0.002). The mean preoperative EIFL thickness was 169.15 µm and decreased to 95.70 µm at 3 months (P = 0.001) and 90.95 µm at 6 months (P = 0.02). Similarly, CMT reduced from 510.00 µm preoperatively to 444.56 µm at 3 months (P < 0.001) and 415.50 µm at 6 months (P < 0.001). Reduction in EIFL thickness was significantly correlated with improvement in log-MAR VA (P =0.02) 6 months after surgery.

Conclusion: ERM peeling results in reduced EIFL thickness, restoration of the normal foveal pit structure, and a corresponding improvement in visual acuity. Reduction in EIFL thickness is correlated with visual improvement.