Amaurosis Fugax - Causes, Symptoms & Treatment

Amaurosis fugax involves loss of vision in one eye caused by a temporary lack of blood flow to the retina. It is a common clinical symptom indicative of transient retinal ischaemia, usually associated with stenosis of the ipsilateral carotid artery or emboli (cardiac and aortic). It is often described as a curtain passing across the eye. Amaurosis fugax is a temporary, monocular , partial blindness lasting as little as a few seconds to as long as 2 hours.  Afterward, vision returns to normal, but the underlying cause must be investigated.

Amaurosis fugax is caused by partial loss of blood flow to the eye as a result of an embolus temporarily blocking circulation to the retina. The embolus may take the form of a plaque, which breaks loose from the carotid artery (in the neck), or a thromboembolus , which develops in the heart, and subsequently breaks loose into systemic circulation. Other causes are much less common. Patients are generally evaluated for carotid artery atherosclerotic (narrowing) disease with carotid doppler ultrasound and, in many cases, with an echocardiogram to further evaluate for cardiac disease. Aspirin is often prescribed to decrease the risk of stroke . 

Causes of Amaurosis Fugax

Amaurosis fugax is thought to result from a clot of plaque in the carotid artery breaking off and traveling to the retinal artery in the eye. This blocks the artery for a time and causes loss of vision in that eye for as long as its blood supply is cut off. Atherosclerosis of the carotid arteries (in the neck) is the main risk factor for this condition. Risk factors for atherosclerosis include heart disease , high cholesterol , smoking, diabetes , and high blood pressure .

• High blood pressure.
• Smoking.
• Heart disease.
• Diabetes .
• High cholesterol.

Signs and Symptoms of Amaurosis Fugax

The most common symptom is sudden blindness in one eye that goes away quickly. It is often described as feeling like the pulling of a curtain or a shade over one eye. It is not painful. The other eye is usually not affected. Some patients describe the loss of vision as a gray or black shade coming down over their eye.

• A "curtain" appears to pass down over the visual field, causing complete loss of vision in the affected eye that lasts a few minutes.

Treatment for Amaurosis Fugax

Treatment depends on the cause, and it is the underlying cause, not the temporary blindness, that is treated. Aspirin or blood thinners may be prescribed to help prevent blood clots. High cholesterol levels, high blood pressure, and diabetes may be treated with diet and medicine. If you smoke, it is very important to stop. If there is a serious blockage of a carotid artery, surgery to remove the blockage (called a carotid endarterectomy) may be considered.

If you like this page, please post it on: