Young woman presents with blurred vision, loss of visual fields

A 19-year-old Hispanic woman with no significant medical or ocular history was referred to the department of ophthalmology at the Lahey Clinic for evaluation of recent acute vision loss.Her history was notable for 1 month of persistent, severe left-sided headache that did not improve with pain medications. One week before presentation, she developed blurred vision in her left eye with loss of central and nasal visual fields and severe pain with extraocular movements. On the day of presentation, she noted ringing in her left ear. She had no significant family history of eye disease. She had no history of blood transfusions and did not smoke, drink alcohol or use illicit drugs. Complete ocular and systemic review of symptoms was negative except as noted above. A CT scan of the head obtained before presentation was unremarkable.