Acute Macular Neuroretinopathy in Association with Orbital Inflammation and Optic Perineuritis

A 17-year-old girl experienced acute onset of decreased vision with pain on movement in her left eye. Her best-corrected visual acuity was 20/20 in the right eye and 20/100 in the left eye. Pupillary examination revealed a positive relative afferent pupillary defect. Fundus examination showed optic disc hyperemia and retinal folds. A central scotoma was detected on a perimetry test. Fluorescein angiography indicated mild disc leakage in the late phase. Orbital magnetic resonance imaging disclosed enhancement in the soft tissue of the left retrobulbar area and at the sheath of the left optic nerve. Optical coherence tomography (OCT) revealed subretinal fluid at the fovea, disruption of the ellipsoid zone (EZ), a hyper-reflective band at the outer plexiform layer (OPL), and hyper-reflective foci (HRF) in the inner retinal layer. Pulse therapy was administered, followed by oral steroid tapering. One week later, OCT showed almost complete resolution of subretinal fluid, no HRF, partial improvement in the thickening of the OPL, but persistent EZ disruption. One month later, her vision in the left eye improved to 0.6. Here we present a rare case of AMN associated with orbital inflammation and optic perineuritis, mimicking acute optic neuritis. Although the status of myelin oligodendrocyte glycoprotein (MOG) antibodies in our patient remains uncertain, her ophthalmologic manifestations strongly suggest myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). This study highlights the importance of OCT examination, especially macular scanning, for establishing a proper diagnosis.