Optic Neuropathy due to Chronic Lymphocytic Leukemia Proven With Optic Nerve Sheath Biopsy and Chronic Myelogenous Leukemia Relapse Presenting With Central Nervous System Blast Crisis and Bilateral Optic Nerve Infiltration (2016)

We read with great interest the articles by Khan et al (1) and Mbekeani et al (2) entitled “Optic neuropathy due to chronic lymphocytic leukemia proven with optic nerve sheath biopsy” and “Chronic myelogenous leukemia relapse presenting with central nervous system blast crisis and bilateral optic nerve infiltration,” respectively. We found these articles intriguing and particularly pertinent to a case in which we struggled over the correct therapy. A 30-year-old woman reported a 2-month history of buttock pain radiating down her left leg and a 1-month history of painless progressive visual loss in her left eye. She denied any previous ophthalmic problems. She had a history of acute myelogenous leukemia (AML), and 9 months ago she had received induction chemotherapy and 4 cycles of consolidation chemotherapy resulting in complete remission. Examination showed a visual acuity of 20/25, right eye and count fingers, left eye. Color vision was normal in the right eye but the patient could not identify any of the Ishihara color plates with the left eye. There was a left relative afferent pupillary defect (RAPD). Confrontation visual field was normal in the right eye and severely constricted in the left eye. Ocular motility was normal, and there was no ptosis or proptosis. Trigeminal and facial nerves were intact. Anterior and posterior segment examinations were unremarkable. Contrast-enhanced fat-suppressed brain and orbital magnetic resonance imaging (MRI) studies showed focal enlargement and enhancement of the intracranial segment of the left optic nerve (Fig. 1A), and gadolinium-enhanced MRI of the lumbar spine and sacrum showed diffuse leukemic vertebral body marrow infiltration, enlargement and enhancement of lower exiting lumbar nerve roots as well as distal cauda equina nerve roots, and enlargement of the S1 and S2 nerve roots bilaterally (Fig. 1B).FIG. 1: Postcontrast axial T1 magnetic resonance imaging with fat suppression reveals thickening and enhancement of the prechiasmal portion of the left optic nerve (arrow) (A), and enlargement of the spinal sacral nerve roots (arrows) (B).The patient was admitted to the hospital, prescribed high dose IV methylprednisolone, and received intravenous cytarabine (Ara-C) 4,600 mg over 3 hours every 12 hours and a 70-mg intrathecal injection of Ara-C. The patient's vision did not improve over the next 5 days, and we thought we would have to consider radiotherapy. However, on day 7, to our amazement, the patient's left visual acuity was 20/20 with normalization of the rest of the neuro-ophthalmologic examination including a lack of an RAPD. A variety of therapies have been proposed for leukemic infiltration of the optic nerve for chronic lymphocytic leukemia, chronic myelogenous leukemia, and AML including intrathecal chemotherapy and radiotherapy (1–6). Our case supports the observations of Khan et al (1) and Mbekeani et al (2) that chemotherapy alone may be enough to restore normal acuity and radiotherapy may not be necessary, at least initially during the acute episode of visual loss.