Abstract
A patient presents with vision loss in the right eye with associated painful eye movements and dulling of color vision that began 3 weeks prior to presentation. Examination reveals hand motion visual acuity in the right eye as well as macular ganglion cell layer thinning on optical coherence tomography (OCT), and increased P100 latency on visual evoked potential (VEP) in the right optic nerve. MRI brain and orbits show enhancement of the right intra-orbital and intra-canalicular segments of the right optic nerve consistent with acute optic neuritis. Patient received 5 days of intravenous (IV) steroids without improvement in visual acuity. They subsequently presented with vision loss in the left eye, 1 month after their right eye symptoms began, and were found to have mild decrement in visual acuity and increased P100 latency on VEP in the left eye, without any new enhancement on MRI or changes on OCT. Patient was admitted and received 7 days of plasmapheresis (PLEX) for steroid-refractory sequential optic neuritis and an additional 4 days of IV steroids, followed by an oral steroid taper. Repeat examination in the neuro-ophthalmology clinic revealed significant improvement in their visual acuity, from hand motion to now 20/50 in the right eye. Bloodwork confirmed AQP4 antibody positivity and the patient was diagnosed with neuromyelitis optica spectrum disorder (NMOSD). This case highlights that even though early initiation of PLEX is associated with the best visual outcomes in NMOSD-associated optic neuritis, escalation to PLEX for steroid-refractory optic neuritis can yield meaningful visual recovery even when presentation is delayed.
Presentation Date: 10/15/2026
Issue Date: 10/16/2026
