Ischemic Optic Neuropathy
What is Ischemic Optic Neuropathy?
Ischemic optic neuropathy is the sudden loss of vision due to an interruption in blood flow to the optic nerve. The optic nerve carries visual information from the eye to the brain, where images are interpreted. When blood flow to the nerve is interrupted, the nerve is deprived of oxygen and nutrition. This can lead to vision loss.
When blood flow to the front part of the optic nerve is reduced or blocked, it is called anterior ischemic optic neuropathy. When blood flow to the back part of the nerve is interrupted, it is called posterior ischemic optic neuropathy.
There are two forms of anterior ischemic optic neuropathy:
- Arteritic – This form is caused by inflammation of the arteries that supply blood to the optic nerve. The inflammation is due to a condition called giant-cell arteritis or temporal arteritis, which is potentially life-threatening and can cause massive vision loss.
- Nonarteritic – This form is caused by a sudden decrease in the circulation of blood in the arteries that supply the optic nerve. It has less of an impact on visual outcome than the arteritic form.
Ischemic Optic Neuropathy Symptoms
Most people with arteritic anterior ischemic optic neuropathy experience other symptoms before vision loss, such as:
- Overall fatigue
- Pain in the temples
- Pain when chewing
- Neck pain
- Scalp pain or tingling
- Muscle aches and pains, particularly in the upper legs or arms
- Loss of appetite
- Unexplained weight loss
The key vision-related symptom of the arteritic form is painless, temporary blurriness or loss of vision lasting several minutes or hours before vision loss becomes permanent.
The nonarteritic form usually manifests as sudden, painless vision loss in one eye.
The presence of these symptoms does not necessarily mean you have ischemic optic neuropathy. Contact a medical professional if you are experiencing symptoms.
Treatments for Ischemic Optic Neuropathy
There is no treatment specifically for vision loss associated with nonarteritic anterior ischemic optic neuropathy, but treating underlying conditions that are risk factors for the condition may help prevent further vision loss.
Treatment for the arteritic form is immediate corticosteroid therapy. Corticosteroids usually do not reverse vision loss that has already occurred, but they may help prevent vision loss in the unaffected eye.
How common is ischemic optic neuropathy?
Ischemic optic neuropathy is one of the most common causes of vision loss in people older than middle age. Anterior ischemic optic neuropathy is more common than the posterior form, accounting for about 90 percent of cases. Nonarteritic anterior ischemic optic neuropathy is more common than the arteritic form.
Who gets ischemic optic neuropathy?
Arteritic anterior ischemic optic neuropathy usually affects people over age 55 and is three times more common in women than in men. The nonarteritic form mostly affects people over age 50, but it can occur at any age. The nonarteritic form occurs in men and women at equal rates.
The following conditions may increase a person’s risk of developing the nonarteritic form:
- High blood pressure
- Diabetes mellitus
- High cholesterol
- Sleep apnea
- Heart disease
- Blocked arteries
- Anemia or sudden blood loss
- Sudden drop in blood pressure
- Sickle cell trait
- Vasculitis (inflammation of blood vessels)
How is ischemic optic neuropathy diagnosed?
The following may tests may be used to diagnose ischemic optic neuropathy:
- Eye examination
- Blood tests
- Biopsies of arteries in the temple area of your head
- Imaging tests involving the injection of a fluorescent dye into your bloodstream