Optic nerve glioma/Definition

Glial cell derived tumors arising from the optic nerve, usually presenting in childhood. Roughly 50% are associated with neurofibramatosis  1. Clinical manifestations include decreased visual acuity; exopthalmos, pathologic nystagmus and strabismus; pallor or swelling of the optic disc; and intracranial hypertension; The tumor may extend into the optic chiasm and hypothalamus. (Adams et al., Principles of Neurology, 6th ed, p681)