Amaurosis fugax

Definition

Amaurosis fugax is a temporary loss of vision in one or both eyes due to a lack of blood flow to the retina. The retina is the light-sensitive layer of tissue at the back of the eyeball.

Causes

Amaurosis fugax is not itself a disease. Instead, it is a sign of other disorders. Amaurosis fugax can occur from different causes. One cause is when a blood clot or a piece of plaque blocks an artery in the eye. The blood clot or plaque usually travels from a larger artery, such as the carotid artery in the neck or an artery in the heart, 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:

Amaurosis fugax can also occur because of other disorders such as:

Symptoms

Symptoms include the sudden loss of vision in one or both eyes. This usually lasts for a few seconds to several minutes. Afterward, vision returns to normal. Some people describe the loss of vision as a gray or black shade coming down over the eye.

Exams and Tests

The health care provider will perform a complete eye and nervous system exam. In some cases, an eye exam will reveal a bright spot where the clot is blocking the retinal artery.

Tests that may be done include:

Treatment

Treatment of amaurosis fugax depends on its cause. When amaurosis fugax is due to a blood clot or plaque, the concern 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.

Outlook (Prognosis)

Amaurosis fugax increases your risk for stroke.

When to Contact a Medical Professional

Call your provider if any vision loss occurs. If symptoms last longer than a few minutes or if there are other symptoms with the vision loss, seek medical attention right away.


Review Date: 4/30/2018
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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