Nonarteritic Anterior Ischemic Optic Neuropathy: Review and Update.

Nonarteritic anterior ischemic optic neuropathy (NA-AION) is a major cause of blindness in patients above the age of 50 years that is believed to occur due to insufficient blood supply to the optic nerve head. Patients typically present with sudden-onset, unilateral, painless vision loss accompanied by decreased visual acuity and field. Diagnostic work-up includes taking a thorough history and clinical examination including relative afferent pupillary defect, visual fields, and optical coherence tomography. Despite the abundance of NA-AION, there are currently no definitive treatment options, though different surgical and medical treatments exist for the treatment of NA-ION.