Evaluating ERM Stage and DRIL as predictive biomarkers for functional outcomes after iERM surgery

BACKGROUND: Predictive optical coherence tomography (OCT) biomarkers for functional outcome after epiretinal membrane (ERM) surgery could aid clinicians in treatment decisions. Available studies on biomarkers for epiretinal membrane surgery remain inconclusive on their predictive value. The aim was to evaluate the association of ERM stage and disorganization of retinal inner layers (DRIL) with functional outcomes after ERM surgery. The study was conducted at the Department of Ophthalmology at the TUM University Hospital. METHODS: For this retrospective cohort study, medical records were analyzed for a consecutive sample of patients diagnosed with idiopathic ERM between 01.01.2018 and 01.01.2023 and treated with ERM peeling. Clinical examination and OCT scans were evaluated prior to surgery, and at 1, 3, 6, and 12 months postoperatively. Patients with idiopathic epiretinal membrane were included if they had at least one follow-up examination between 3 and 12 months after surgery. Patients with secondary ERMs, other conditions affecting best-corrected visual acuity (BCVA), or a history of intraocular surgery (except for uncomplicated cataract surgery) were excluded. The criteria were met in 131 eyes of 126 patients, and the 12-month follow-up examination was completed in 64 eyes. Exploratory associations between functional outcomes (BCVA and metamorphopsia) 12 months after surgery and potential OCT biomarkers (ERM stage, DRIL) using regression analysis. RESULTS: The inclusion criteria were met for 131 eyes of 126 patients with a mean (SD) age of 70.3 (7.4) years. 62 (49.2%) patients were female, and 64 (50.8%) were male. Mean (SD) BCVA improved from 0.37 (0.21) logMAR to 0.15 (0.16) logMAR 12 months after surgery. Neither preoperative ERM stage (adjusted β=-0.003, 95% CI: -0.057-0.052, p = 0.927) nor DRIL category (adjusted β = 0.014, 95% CI: -0.056-0.084, p = 0.693) was associated with BCVA 12 months after surgery. CONCLUSIONS: Neither biomarker was associated with BCVA 12 months after surgery. BCVA at baseline remained the only significant parameter. Reported effect sizes can be used in future confirmatory studies.