Bilateral non-arteritic posterior ischaemic optic neuropathy following COVID-19 vaccination.

We report a case of bilateral posterior ischaemic optic neuropathy, which followed vaccination with ChAdOx1 nCoV-19 for COVID-19 prophylaxis. A man in his early 60s was initially assessed for bilateral acute vision loss following 3 days of frontal headaches. The patient denied any other preceding visual concerns or symptoms of giant cell arteritis. The patient received his first dose of the ChAdOx1 nCoV-19 vaccination 10 days before the onset of his symptoms.At initial presentation, visual acuity was counting fingers bilaterally. Blood work found normal erythrocyte sedimentation rate (6 mm/hour) and C reactive protein (<5 mg/L) as well as a negative infectious and autoimmune serology. He was negative for COVID-19 with PCR testing. Diffusion-weighted MRI showed restricted diffusion along both optic nerves. After 5 months, the patient's visual acuity remained counting fingers bilaterally with pale optic nerves. Isolated bilateral posterior ischaemic optic neuropathy has not been reported in association with the ChAdOx1 nCoV-19 vaccine.