Optochiasmatic and peripheral neuropathy due to ethambutol overtreatment.

Ethambutol is known to cause optic neuropathy and, more rarely, axonal polyneuropathy. We characterize the clinical, neurophysiological, and neuroimaging findings in a 72-year-old man who developed visual loss and paresthesias after 11 weeks of exposure to a supratherapeutic dose of ethambutol. This case demonstrates the selective vulnerability of the anterior visual pathways and peripheral nerves to ethambutol toxicity.

Pancreatic neuroendocrine paraneoplastic optic neuropathy: confirmation with antibody to optic nerve and hepatic metastasis.

A 68-year-old woman presented with bilateral visual loss as the only clinical manifestation of an occult pancreatic nonsecretory neuroendocrine tumor (NET). The suspected diagnosis of paraneoplastic optic neuropathy was confirmed using immunofluorescence assays to demonstrate the presence of antibodies in the patient's serum that reacted with antigen(s) in the optic nerve and in the pancreatic NET hepatic metastasis. Treatment of the underlying cancer was followed by marked improvement in visual function.