Amaurosis fugax is a loss of vision caused by a temporary blockage of blood flow to the retina. The amount of vision loss ranges from partial to total blindness; it can occur suddenly and last from just a few seconds up to ten minutes. Patients describe the loss of vision as being like a black or gray shade coming down over their eye. When blood flow resumes, vision returns to normal.
The blockage of blood flow is caused when a piece of plaque breaks off in the carotid artery and interrupts the flow of blood in the artery to the retina. Plaque is a very hard material that accumulates on the walls of an artery. It consists of cholesterol, fat and other hard substances which are present in blood.
People who suffer atherosclerosis resulting from heart disease, diabetes, high cholesterol and high blood pressure have a higher risk of amaurosis fugax. Smokers also have a higher risk. While amaurosis fugax does not cause permanent blindness, it is a sign that a patient may have atherosclerosis, which can cause a heart attack or stroke.
The diagnosis of amaurosis fugax starts with a thorough examination of the affected eye plus a neurological examination. The doctor uses the eye exam to look for red spots that indicate the presence of a blockage in the retinal artery. If the doctor identifies a blockage, he may order an ultrasound of the carotid or magnetic resonance angiogram (MRA). Since amaurosis fugax is a sign of atherosclerosis, further tests should be conducted for cholesterol and glucose levels.
Treatment of amaurosis fugax depends on the amount of blockage in the carotid artery. The objective of the treatment is to reduce the possibility of the patient having a stroke. A doctor will usually prescribe a blood thinner, such as warfarin and aspirin, to lessen the risk of stroke. If the tests show the patient has high cholesterol or high blood pressure, the doctor may recommend changes in diet in addition to medication. Afterwards, the patient should have regular check-ups to monitor the condition of the carotid artery.
Since amaurosis fugax is an indication of atherosclerosis, a mistake in the diagnosis could delay treatment of this more severe underlying problem. Sometimes, amaurosis fugax is mistakenly diagnosed as cardiac emboli or retinal detachment. In these instances, the doctor may prescribe the wrong treatment, and the atherosclerosis will continue to exist and remain untreated.
A mistake in diagnosing amaurosis fugax can cause a patient to have a stroke by not properly treating the underlying condition of atherosclerosis. A patient who has been misdiagnosed may have a cause of action as a basis for medical malpractice. These patients are advised to seek the advice of lawyer to determine the possibility of compensation for medical expense and lost wages.