Significant Visual Field Defects Persist Despite Excellent Visual Acuity Following Optic Neuritis in Myelin-Oligodendrocyte Glycoprotein Associated Disease

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a rare autoimmune demyelinating disorder. In adults, optic neuritis (ON) is the most common clinical manifestation. MOGAD-ON can severely affect visual acuity (VA) and cause visual field (VF) deficits. VA typically improves rapidly with treatment, but little is known about VFs at follow-up. To address this, we analyzed VFs in MOG-ON patients. We conducted a multicentre international retrospective review of MOGAD-ON patients. VFs were obtained at presentation and follow-up at least 3 months later and before the next relapse. VF severity was based on the mean deviation (MD) measurements graded as mild, moderate, or severe. Specific VF deficit patterns and shapes were assessed by a single-blinded neuro-ophthalmologist (as per Optic-Neuritis-Treatment-Trial Group). Time to treatment was also assessed. Thirty-nine eyes of 28 patients were included (mean age 39.68 ± 12.9 years, 13 males). The average MD nadir from all 39 affected eyes was -14.18 (±9.8 dB) and -3.02 (±3.2 dB) at follow-up. At follow-up, 46% of the eyes developed permanent VF deficits with an MD below -2 dB. (41% with a recognizable VF deficit pattern) despite recovery to an average VA of 6/6. In contrast to visual acuity, visual fields showed poorer recovery with persistent deficits in MOGAD patients with optic neuritis despite treatment. An altitudinal VF defect in a patient with prior acute optic neuropathy with disc edema should not preclude the consideration of MGOAD as the diagnosis.