Optic nerve sheath meningiomas: clinical features, functional prognosis and controversial treatment.

Optic nerve sheath meningiomas (ONSM) are rare benign neoplastic lesions arising from meningothelial cells of the meninges. As clinical features are highly variable, the diagnosis is often delayed. From 1995 to 1999, 6 patients were diagnosed with ONSM in our department. We compared our series with the literature data. Visual prognosis is usually poor. Despite a large literature, the treatment guidelines are still highly controversial.