Bare Retinal Nerve Fiber Layer Associated with Epiretinal Membrane

Researchers assessed pre- and postoperative optical coherence tomography (OCT) characteristics of bare retinal nerve fiber layer (bRNFL) and internal limiting membrane (ILM) tear associated with epiretinal membrane (ERM). They found that bRNFL was significantly more likely to have a higher grade of ERM. The results of the study were published as part of the American Society of Retina Specialists 2020 Virtual Annual Meeting.

This retrospective chart review included 158 consecutive patients with idiopathic ERM either with (n=19; group A; mean age, 65.26 years) or without (n=139; group B; mean age, 65.09 years) bRNFL who underwent pars plana vitrectomy by a single surgeon between March 2016 and May 2019. bRNFL diagnosis was made based on intraoperative findings, and masked observers confirmed the surgeon’s intraoperative clinical impression by studying the operating video. Preoperatively and at one, three, and six months postoperatively, researchers assessed best-corrected visual acuity (BCVA) and spectral domain OCT with infrared imaging.

Group A was significantly more likely to have a higher grade of ERM (P=0.001) compared with group B. Typically, the torn ILM is seen as a thin scrolled uniform layer in OCT, correlated frequently with schisis of RNFL, and resolved postoperatively. Researchers also found hyporeflective bands on near-infrared fundus images corresponding to rolled-up edge of torn ILM. The bands were characterized by a convex contour toward the center of the fovea.

Retinal area adjacent and peripheral to rolled-up edge of torn ILM, corresponding to bRNFL, showed a less retinal folding preoperatively and distributed outside the parafovea in most cases. Mean logarithm of the minimum angle of resolution BCVA improved from 0.47 and 0.32 at baseline to 0.21 and 0.15 months after surgery in both groups (P=0.001 and P<0.001, respectively). Although mean central foveal thickness (CFT) progressively improved in both groups, the mean change of CFT of group A was greater than group B (P=0.001).

“Vitreoretinal surgeons should be aware of the presence of bRNFL with ILM tear through review of preoperative OCT and fundus photograph to minimize surgical trauma,” the researchers concluded.

Kim JG, Yeo JH. Bare Retinal Nerve Fiber Layer and Internal Limiting Membrane Tear Associated with Epiretinal Membrane: OCT Findings and Visual Outcomes. Presented during the ASRS 2020 Virtual Annual Meeting, July 24-26, 2020.