What is Amaurosis Fugax Caused by?
Amaurosis fugax, also called transient visual loss or transient monocular blindness, is a sudden loss of vision in one or both eyes. It’s caused by decreased blood flow in the retina. The retina is a thin layer on the back of the eye that communicates light signals to the brain.
Amaurosis fugax is caused by a blood clot or disturbance in blood vessels associated with:
- Retinal circulation
- Internal carotid artery
- Optic nerve (communication pathway between the eye and brain)
The condition typically lasts from a few seconds to a few minutes before vision returns.
Amaurosis fugax can signify an impending stroke. It should be evaluated immediately by an eye doctor or medical professional.
Is Amaurosis Fugax a Mini Stroke?
Amaurosis fugax that develops in one eye, typically from ruptured plaque (hardening of the arteries) in the internal carotid artery, is called transient monocular visual loss. It’s considered a form of transient ischemic attack (TIA).
A TIA, or mini-stroke, is a localized stroke (disruption of blood flow to the brain) that lasts only a few minutes. A mini-stroke can be a warning sign of a future stroke, so it is essential to seek immediate medical attention.
Symptoms of a TIA include:
- Numbness or weakness on one side of the body
- Difficulty with balance or walking
- Loss of vision in one or both eyes
- Trouble speaking
People over age 50 are at a higher risk of experiencing amaurosis fugax.
Other risk factors include:
- High blood pressure
- High cholesterol
- Cerebrovascular disease
- Cocaine use
- Heart disease
- Carotid artery disease
- Migraine headaches
- Eye inflammation (optic neuritis)
- Brain tumor
- Head injury
- Multiple sclerosis (MS)
- Significant carotid stenosis (narrowing of carotid artery)
Transient vision loss caused by amaurosis fugax is painless and typically lasts a few seconds or minutes before full vision returns on its own. The condition rarely leads to permanent vision loss.
Reported symptoms of amaurosis fugax include:
- A dark curtain over the eye(s)
- Temporary loss of vision in one or both eyes
- Blurred vision
People over age 60 who experience multiple episodes of amaurosis fugax are at risk for giant cell arteritis (inflammation of blood vessels in the scalp, neck, and arms).
What are the Treatments for Amaurosis Fugax?
Since amaurosis fugax is caused by an underlying medication condition, the first step is to treat the cause of temporary vision loss.
The most critical goal in treating amaurosis fugax is to prevent a stroke.
To evaluate the cause of vision loss, medical professionals will typically conduct a physical assessment, medical history, and order tests, including:
- Full eye exam
- Blood tests and laboratory tests (complete blood count, blood glucose, lipid profile)
- Carotid doppler used to look at blood vessels
- Neuroimaging scans (CT scans) to rule out stroke or brain injury
- Magnetic resonance angiography (scans carotid artery for blood clots)
Depending on the cause of amaurosis fugax, a healthcare professional will prescribe a treatment plan that may include:
- Blood thinners
- Anticoagulants (prevents blood from clotting)
- Carotid stenting (expanding a narrow blood vessel)
- Medication to lower blood pressure
- Carotid endarterectomy (cleans out plaque in the internal carotid arteries)
A medical professional can guide you on at home interventions to help manage and prevent amaurosis fugax episodes, including:
- Quitting smoking
- Daily physical exercise
- Eliminating high-fat foods from your diet
- Controlling chronic conditions (diabetes, hypertension, heart disease, etc.)
Can It Be Reversed?
While amaurosis fugax will typically go away on its own after a few minutes, it can be the sign of an underlying medical condition or an upcoming stroke.
The risk of complications from a stroke increases as treatment is delayed.
Complications can include:
- Adverse cardiac events
When to See a Doctor
It is essential to seek medical attention immediately if you experience sudden particle or total vision loss.
Experiencing an amaurosis fugax episode, cardiovascular disease, ocular migraine, or a head injury puts you at a higher risk of complications and stroke.
Amaurosis fugax is a temporary loss of vision in one or both eyes caused by blood clots or disturbance in blood flow. It’s typically caused by a blockage or plaque in the carotid artery, retina, or optic nerve.
This condition can indicate an underlying medical condition and puts you at a higher risk of stroke. You should seek immediate medical attention for sudden vision loss or blindness.
In this article