Effect of ERM on RNFL, GCIPL and Macular Thickness According to the Severity of Glaucoma

Purpose: To investigate the effect of an epiretinal membrane (ERM) on peripapillary retinal nerve fiber layer thickness (pRNFLT), macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and macular thickness (MT) in relation to glaucoma severity using swept-source optical coherence tomography (SS-OCT).Methods: In total, 105 eyes of 105 glaucoma patients with ERM were matched at a 1:1 ratio with glaucoma patients without ERM according to age, sex, cataract surgery, axial length and mean deviation based on visual field tests. The differences in pRNFLT, mGCIPLT and MT between the two groups were assessed using SS-OCT. Furthermore, the patients were divided into three glaucoma-severity groups, and the differences in pRNFLT, mGCIPLT and MT were compared between glaucoma patients with and without ERM in each group.Results: In all patients, including those with early, moderate, and advanced glaucoma, those with ERM had greater average, temporal quadrant, and 7, 8, 9, 10, and 11 o’clock pRNFLT values compared to those without ERM. Additionally, mGCIPLT and MT were thicker in glaucoma patients with ERM in all groups. The difference in pRNFLT at the 7 and 11 o’clock positions between glaucoma patients with and without ERM was significantly more pronounced in the moderate glaucoma group than in the early glaucoma group (p = 0.043 and p = 0.012, respectively).Conclusions: ERM has notable effects on the pRNFLT, mGCIPLT and MT. Furthermore, the magnitude of its effect on pRNFLT varies with glaucoma severity.