Optic atrophy following prophylactic chemotherapy and cranial radiation for acute lymphocytic leukemia.

Two patients with acute lymphocytic leukemia developed progressive optic nerve and chiasmal lesions eight to nine months after the initiation of identical chemotherapy protocols that included intrathecal medication and prophylactic radiation of only 2,400 rads to the central nervous system. Both patients eventually lost all vision despite additional radiotherapy, and there was no evidence of leukemia involving the central nervous system after acute lymphocytic leukemia was diagnosed. Optic nerve biopsy in one case showed changes consistent with radiation necrosis.