Changes in the Hyperreflective Bands of Outer Retinal Layers after Idiopathic Epiretinal Membrane Surgical Removal.

Purpose: The purpose of this study was to describe the relationship between the outer retinal hyperreflective bands and visual acuity recovery after idiopathic epiretinal macular membrane (ERM) surgical removal. Methods: A prospective longitudinal non-comparative study was conducted that included a total of 68 patients with idiopathic ERM, who underwent consecutive 23 G pars plana vitrectomy (PPV) at San Juan University Hospital (Alicante, Spain) from January 2019 to January 2021. All patients underwent a complete preoperative standard ophthalmic examination, including measurement of best corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) examination. This protocol was repeated at 1 and 3 months after surgery. Results: Mean preoperative decimal BCVA was 0.30 ± 0.13 and disruption of the first, second, third and fourth outer retinal hyperreflective bands was observed by SD-OCT in 9 (27.9%), 27 (39.7%), 33 (48.5%) and 17 patients (25%), respectively. BCVA improved after ERM peeling at 1 and 3 months in all patients, regardless of the presence of disruption in any hyperreflective band. Significantly larger improvement of BCVA was found at 3 months after surgery in patients not showing disruption of hyperreflective bands 1 and 4 ( p  = 0.048 and 0.001, respectively). Conclusions: The integrity of the outer retinal hyperreflective bands by SD-OCT in patients with idiopathic ERM is a valuable tool to determine the visual prognosis of the surgical treatment of this condition. A successful recovery of hyperreflective bands 1 and 4 with ERM surgery may be a potential biomarker of the visual improvement achieved due to their important anatomical relation with cone photoreceptors at the foveal level.