Clinical Challenge: Looking beyond blurred margins

A 60-year-old man presented to an outside ophthalmology clinic with 1 month of progressive vision loss in the right eye (OD). Right optic disc edema was noted. Brain and orbit magnetic resonance imaging revealed right optic nerve and left occipital lobe enhancement. He was seen initially by neurology and neurosurgery and subsequently referred to neuro-ophthalmology for consideration of optic nerve biopsy. He was seen 3 months after his initial symptom onset where vision was light perception OD and a relative afferent pupillary defect with optic nerve edema. OS was unremarkable. A lumbar puncture with flow cytometry was negative for multiple sclerosis and lymphoma. At his oculoplastic evaluation for optic nerve biopsy, his vision was noted to be no light perception OD. Optic nerve biopsy demonstrated non-caseating granulomatous inflammation. The patient was started on high-dose oral steroids with improvement of disc edema, as well as significant improvement in optic nerve and intracranial parenchymal enhancement, although his vision never improved.