Neurosarcoidosis presenting as CRVO combined CRAO: a biopsy-proven case report of a Chinese patient.

Isolated optic nerve infiltration by neurosarcoidosis without the involvement of the central nervous system or other systemic organs is challenging to diagnose. Biopsy of the optic nerve sheath is crucial for the final diagnosis of neurosarcoidosis. Therefore, a comprehensive ophthalmologic and systemic examination and work-up for inflammation of the eye, chest, and central nervous system should be conducted for atypical cases.