Glioma: A tumor of astrocytes of the optic nerve is an optic nerve glioma. The patient presents with proptosis and often gradual visual loss. CT scan reveals a thickened optic nerve. Pathology reveals glial cells separated by myxoid spaces and loose, connective tissue. Rosenthal fibers which are intracytoplasmic, eosinophilic structures can be seen in the astrocytes. Back to Optic Nerve