Spontaneous Resolution of a Unilateral Epiretinal Membrane in Bilateral Peripheral Retinal Vasculopathy: A Case Report

Background and Clinical Significance: Epiretinal membranes (ERMs) are uncommon in young patients, and spontaneous anatomical resolution is rare. We report spontaneous disappearance of a unilateral ERM after marked worsening in an 18-year-old woman with bilateral peripheral occlusive/telangiectatic retinal vasculopathy and vitritis of undetermined etiology. Case Presentation: She presented with right-eye (RE) metamorphopsia and uncorrected visual acuity of 20/25. Optical coherence tomography (OCT) showed a macular ERM; fluorescein angiography showed bilateral peripheral telangiectasia, leakage, vascular truncation, and capillary nonperfusion. Bilateral vitritis was present. Treatment comprised a single intravitreal ranibizumab injection in the RE and peripheral laser photocoagulation in both eyes for the vascular abnormalities; the ERM was managed conservatively. Before its disappearance, the ERM showed marked anatomical worsening accompanied by progressive visual decline. RE central macular thickness (CMT) peaked at 901 µm on Day 71; the lowest uncorrected visual acuity, 20/200, was recorded on Days 166 and 187. Posterior vitreous detachment was not clinically detectable throughout follow-up. On Day 243, the ERM was first documented as absent clinically and on OCT; visual acuity with correction was 20/30, CMT was 464 µm, and vitritis was no longer clinically detectable. At approximately 38 months, macular contour remained restored and recorded visual acuity was 20/20 in both eyes. When mapped to the MANE Select transcript, the retained VCAN variant notation corresponds to NM_004385.5:c.2234A>C (p.Lys745Thr); ClinVar reports conflicting classifications, and the finding was therefore considered non-diagnostic. Conclusions: This case documents spontaneous ERM disappearance without vitreoretinal surgery after marked anatomical and functional worsening. The separation mechanism and any causal contribution of ranibizumab or laser photocoagulation remain uncertain.