Optic nerve sheath meningiomas

Optic nerve sheath meningiomas are an uncommon cause of slowly progressive visual loss, usually unassociated with proptosis or motility disturbances. They are usually discovered on clinical examination and are best defined by MRI scan with fat sat and gadolinium. Conformal fractionated radiation therapy is currently the most effective treatment available. Primary optic nerve sheath meningiomas must be distinguished from those arising from the tuberculum and secondarily affecting the optic nerve that may be treated with decompression at the orbital apex.