Vision Information - Ischemic Optic Neuropathy
Ischemic optic neuropathy refers to damage to the optic nerve caused by a blockage of its blood supply.
The condition is caused by blockage of the blood supply to the part of the optic nerve within the eye and can lead to impaired function of optic nerve cells. Two types of ischemic optic neuropathy are designated - nonarteritic and arteritic.
Usually people over the age of 50 contract nonarteritic ischemic optic neuropathy. Several risk factors include high blood pressure, diabetes, and atherosclerosis. The condition rarely occurs in young people but it can occur in younger people with severe migraines.
Arteritic ischemic optic neuropathy is typically found in people older than 70. The blood supply to the optic nerve is blocked due to inflammation of the arteries (arteritis), most notably temporal arteritis (giant cell arteritis).
Loss of vision can be almost sudden - within minutes and hours - but may take days. The cause will determine if vision affects both eyes. The range of impairment in the affected eye can be from normal to complete blindness. People with temporal arteritis are typically older and suffer a more severe vision loss. There may be pain on chewing, muscle aches and pains, and pain when combing the hair.
Around 40% of people with nonarteritic ischemic optic neuropathy improve over time and rarely does the condition repeat itself in the same eye. Approximately 20% of people suffer complications in the other eye within five years of the first eye being affected.
If the condition is caused by temporal arteritis, loss of vision in the other eye occurs in 25-50% of people within days or weeks if treatment isn't prompt.
Nonarteritic ischemic optic neuropathy is treated by controlling blood pressure, diabetes, and other factors that affect the blood supply to the optic nerve.
Arteritic ischemic optic neuropathy, caused by temporal arteritis, is treated with high doses of corticosteroids to prevent loss of vision in the other eye. The role of aspirin in preventing complications in the other eye is being investigated, but at this time there is no evidence to support its use.