Optic Neuropathy Due to Chronic Lymphocytic Leukemia Proven With Optic Nerve Sheath Biopsy.

Central nervous system involvement from chronic lymphocytic leukemia (CLL) occurs infrequently, and manifestations include cognitive and cerebellar dysfunction and cranial nerve palsies. We report a 45-year-old man with CLL believed to be in clinical remission, who presented with vision loss and bilateral optic disc edema. His optic neuropathy due to CLL was proven by optic nerve sheath biopsy, and he experienced visual recovery after treatment with ibrutinib and intrathecal methotrexate.