Abstract
Recurrent optic neuritis with optic disc edema may be the initial manifestation of systemic inflammatory disease and can mimic demyelinating optic neuropathy. A patient presented with two months of painless, progressive left-eye visual loss, optic disc edema, a relative afferent pupillary defect, and red desaturation. MRI demonstrated enhancement of the left optic nerve sheath and multiple intracranial enhancing foci, raising concern for malignancy or granulomatous inflammation. Initial laboratory and cerebrospinal fluid investigations were largely unrevealing. Subsequent PET/CT identified mildly FDG-avid lymph nodes and right lacrimal gland uptake. Cervical lymph node biopsy revealed noncaseating granulomas, supporting a diagnosis of systemic sarcoidosis. Visual acuity improved from hand motion to 20/30 following intravenous corticosteroids and an oral prednisone taper. Despite initiation and escalation of mycophenolate mofetil, the patient experienced two further attacks in January 2024 and April 2025. Infliximab was initiated following the third attack. Visual acuity improved after treatment, although a persistent superior-nasal visual field defect remained. Recurrent optic neuritis with optic nerve sheath enhancement warrants evaluation for inflammatory, infiltrative, and neoplastic etiologies beyond demyelination. When routine laboratory testing is nondiagnostic, systemic imaging and tissue biopsy may be essential for establishing sarcoidosis. Early recognition and appropriate immunosuppressive therapy are important in managing recurrent sarcoid optic neuropathy and preserving visual function.
Presentation Date: 10/15/2026
Issue Date: 10/16/2026
