Amaurosis fugax is loss of vision in one eye due to a temporary lack of blood flow to the retina. It may be a sign of an impending stroke.
Transient monocular blindness
Amaurosis fugax is a symptom of carotid artery disease. The carotid arteries are on each side of your neck under the jaw. They provide the main blood supply to the brain.
Amaurosis fugax occurs when a piece of plaque in one of these arteries breaks off and travels to an artery in the eye.
Plaque is a hard substance that forms when fat, cholesterol, and other substances build up in the walls of arteries. Risk factors include:
Symptoms include the sudden loss of vision in one eye. This usually only lasts seconds but may last several minutes. Some patients describe the loss of vision as a gray or black shade coming down over their eye.
Tests include a complete eye and neurological exam. The doctor or nurse will also use a stethoscope to listen to the arteries in your neck.
In some cases, an eye exam will reveal a bright spot where the clot is blocking the retinal artery. A carotid ultrasound or magnetic resonance angiography (MRA) scan should be done to see if you have a blockage in the carotid artery.
Blood tests should be done to check your cholesterol and blood sugar (glucose) levels.
Treatment of amaurosis fugax depends on the severity of the blockage in the carotid artery. The goal of treatment is to prevent a stroke.
The following can help prevent a stroke:
Your doctor may also recommend:
If a large part of the carotid artery appears blocked, carotid endarterectomy surgery is done to remove the blockage. The decision to do surgery is also based on your overall health.
Amaurosis fugax itself usually does not result in long-term vision loss. However, it means you have an increased risk for stroke.
Call your health care provider if any loss of vision occurs. If symptoms last for longer than a few minutes, or if there are any other symptoms accompanying the visual loss, it is important to seek immediate medical attention.
Goldstein LB, Bushnell CD, Adams RJ, et al. Guidelines for the primary prevention of stroke:a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2011 Feb;42(2):517-84. Epub 2010 Dec 2.