Ectopic inner foveal layer on optical coherence tomography as a prognostic factor for long-term postoperative quantitative metamorphopsia in advanced epiretinal membrane surgery

Abstract

Purpose : Metamorphopsia remains a significant symptom in patients with epiretinal membrane (ERM), persisting pars plana vitrectomy (PPV) treatment. This prospective cohort study aimed to examine the correlation between metamorphopsia and foveal microstructure before and after PPV in a cohort of patients with advanced ERM.

Methods : Consecutive patients between September 2016 and November 2018 with a diagnosis of advanced ERM, which presented ectopic inner foveal layer (EIFL) (stages 3 and 4), treated with PPV were included. The severity of metamorphopsia was quantified using M-CHARTS, and foveal microstructure was evaluated via two optical coherence tomography (OCT) measures: central foveal thickness (CFT) and EIFL. Assessments were performed pre- and post-surgery with an average follow-up of one year. Correlations between morphological and functional parameters pre- and post-surgery were explored by means of regression analysis.

Results : We included 60 eyes from 57 patients (32 male and 25 female) with a mean age of 72.9±7.5. We found a significant correlation between postoperative metamorphopsia and both preoperative (R2=0.43, p<0.01) and postoperative EIFL thickness (R2=0.30, p<0.01) (fig 2).
Patients with stage 3 ERM had higher metamorphopsia scores than those with ERM stage 3, both pre- (0.84 ± 0.32 and 0.46 ± 0.31, respectively, P<0.01) and post-surgery (0.18 ± 0.21 and 0.46 ± 0.28, respectively, P<0.01) (fig 2). Postoperative EIFL thickness was the only variable significantly associated with postoperative metamorphopsia scores according to multivariable regression analysis (p<0.01).

Conclusions : The study underlines the importance of EIFL thickness in determining the severity of metamorphopsia 1 year after macular surgery. Monitoring EIFL thickness may be crucial for optimizing visual outcomes and reducing the impact of metamorphopsia. Furthermore, our findings provide insight into functional and anatomical outcomes following ERM surgery.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.