Nonarteritic anterior ischemic optic neuropathy.

Nonarteritic anterior ischemic optic neuropathy is a common cause of sudden, painless loss of vision present commonly on awakening from sleep. It most commonly affects middle-aged and elderly Caucasian men and women. Involvement of the opposite eye occurs within 3 years in less than 43% of patients. Hypertension, diabetes, and nocturnal hypotension are risk factors. A congenital small cup-to-disk ratio also predisposes to the optic nerve ischemia. There is no effective therapy to treat patients acutely or to prevent recurrence. After 6 months of careful follow-up, 57.3% of patients will have no significant change or worsening of their vision in the involved eye.