Background: Bilateral involvement and severe visual impairment can occur in the acute phase of pediatric myelin oligodendrocyte glycoprotein (MOG) antibody-associated optic neuritis (ON), but patients have a generally good prognosis and few have residual severe vision loss. We present the case of a young man with severe bilateral vision loss secondary to MOG antibody-associated ON followed by significant but delayed improvement.
Case Summary: A fifteen-year-old previously healthy male presented with decreased vision in his left eye. He was evaluated at an outside hospital where MRI showed T2 hyperintensity and enhancement of the prechiasmatic left optic nerve and left aspect of the optic chiasm. Neuroimaging also demonstrated multifocal areas of abnormal signal and contrast enhancement within the subcortical white matter including a tumefactive demyelatinating lesion in the right middle frontal gyrus. He was diagnosed with ON and treated with IV steroids. The following month he developed worsening vision in his right eye associated with eye pain and was admitted to our institution. Visual acuity was limited to hand movements in the right eye and count fingers in the left eye. Serum MOG antibody titers were positive (1:40). Due to persistently poor vision, he was treated with IV steroids with an oral taper, two courses of IVIg, and plasmapheresis. Repeat MRI revealed improvement in the multifocal white matter lesions and decreased optic chiasm signal and enhancement, but visual acuity upon discharge remained poor at 20/200 bilaterally.
At six-week follow-up his vision had not improved, so rituximab was started. Ophthalmologic exam more than three months from his initial presentation continued to show poor visual acuity: right eye 20/300 and left eye 20/100. Optical coherence tomography of his retinal nerve fiber layer showed bilateral thinning. On six-month ophthalmology follow-up (four months after the first dose of rituximab) the patients visual acuity had improved to 20/60 in the right eye and 20/40 in the left eye.
Conclusions: This case informs the growing body of literature regarding clinical outcomes of pediatric MOG antibody-associated ON. Our patient demonstrated that prognosis may remain hopeful despite months of persistently poor vision, with delayed improvement in visual acuity.
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Conclusions: not applicable