Glioma of Chiasma and Optic Nerve.

IN a case of orbital optic nerve glioma without intracranial extension, Davis (1940) removed the tumour through a skin incision at the lower orbital margin, cutting the optic nerve near the apex of the orbit and behind the globe and thus retaining the eye. Verhoeff (1922) found that, even when the tumour was partially removed by the orbital route leaving some intracranial portion, no orbital recurrence had been reported. When there was an intracranial prechiasmal extension, Dandy (1941), using a transfrontal approach, divided the optic nerve just anterior to the chiasma and immediately behind the globe to remove the tumour. If the chiasma was involved, Martin and Cushing (1923) avoided surgical intervention as the patient usually died within 48 hours in hyperpyrexia after the operation. In such cases, Katzin (1945), Taveras, Mount, and Wood (1956), and Walsh (1956) treated the tumour by radiation with good results.