Internal limiting membrane (ILM) is usually peeled simultaneously with epiretinal membrane (ERM), however, in eyes with glaucoma and ERM, ILM is preserved in order to prevent nerve fiber damage. The aim of this study was to evaluate if a new approach for ERM is effective to keep ILM during surgery.

Retrospective consecutive case series.

ERM was directly grasped with forceps at the site where the scale of submembrane space imaged in OCT was maximum. After the removal of ERM, ILM was stained with brilliant blue G and the area of remaining ILM was graded with 5 patterns. The relationship between ILM preservation and submembrane space was analyzed with ROC curve.

Thirty-three eyes of 33 patients undergoing ERM surgery (14 women, mean age: 69.2 years) were enrolled. There were 3 eyes with stage 1, 11 eyes with stage 2, 18 eyes with stage 3, and 1 eye with stage 4. The mean maximum distance between ERM and ILM was 80.5 ± 36.0 μm before surgery. ILM was preserved after initial membrane peeling in 21 of 33 eyes (63.6%). ERM-ILM distance correlated with ILM grading (Spearman rank coefficient: P = 0.03). ROC curve analysis identified cutoff value of ERM-ILM distance for ILM preservation was 66 μm[AUC (95% CI):0.7143 (0.5192–0.9093)].

Eyes with larger ERM-ILM distance are likely to show preserved ILM during ERM surgery. ERM-ILM distance appears to be a biomarker of ILM preservation during ERM surgery, which would be useful to minimize neuroretinal damage in eyes with glaucoma and related diseases.