How would you approach treatment of an optic nerve sheath meningioma presenting with complete ipsilateral visual loss?

Radiosurgery to prevent further tumor growth of an optic nerve sheath meningioma in a patient with complete ipsilateral visual loss can technically be accomplished. It is prudent to not include the chiasm nor the very proximal optic nerve due to Wilbrand's knee of the optic chiasm (where crossing fibers can loop forward a few millimeters into the proximal opposite optic nerve). Interestingly, there is some controversy regarding the existence of Wilbrand's knee in normal subjects and that Wilbrand's knee may only be found in patients with monocular blindness.^1,2

A single case report from our institution is available in the literature.³

My colleague, Dr. Scott Stafford, our resident expert on optic nerve sheath meningioma, was consulted and ins...