COVID-19 Associated Optic Neuritis

ABSTRACT

Purpose: While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is well known for its respiratory complications, ocular manifestations are emerging. This case report describes a patient with bilateral optic neuritis associated with coronavirus disease 2019 (COVID-19). Methods: A 46-year-old male presented with two weeks of pain with eye movement immediately after testing positive for COVID-19 and four days of bilateral blurry vision. Data including history, ocular examination, Humphrey visual field testing (HVF), magnetic resonance imaging (MRI), and serological testing was collected. Results: Visual acuity (VA) was 20/100 in the right eye (OD) and 20/70 in the left eye (OS) with pinhole VA of 20/40 in each eye. Pupil exam, intraocular pressures, and confrontational visual fields were normal. Ocular motility was full, however the patient endorsed pain with eye movement in all directions. The right optic nerve had blurred disc margins while the left optic nerve was unremarkable on exam. Color vision was decreased to 13/15 by Ishihara testing in each eye. MRI of the brain and orbits revealed bilateral thickening and T2 hyperintensity and hyperenhancement of the intercanalicular and intraorbital optic nerves with sparing of the nerve sheath and no demyelinating lesions (Figure 1). Bilateral central scotomas were seen on HVF (Figure 2). At this point, the patient's clinical picture was concerning for optic neuritis associated with COVID-19. A complete blood count, comprehensive metabolic panel, myelin-oligodendrocyte glycoprotein antibody, and aquaporin 4 antibody were unremarkable. Testing for tuberculosis, sarcoidosis, syphilis, thyroid disease, and rheumatologic and autoimmune disorders was normal. The patient was treated with corticosteroids. Within three to six weeks, the patient's symptoms and abnormal exam findings resolved. Conclusions: Infectious pathogens and their subsequent inflammation can cause optic neuritis. It is postulated that T cells release inflammatory mediators and cytokines that cross the blood brain barrier and lead to destruction of myelin, neuronal cell death, axonal degeneration, and vision loss. SARS-CoV-2 could cause a similar inflammatory response leading to optic neuritis and is important to consider in cases without a clear etiology.