From the Guidelines
Amaurosis fugax is usually caused by atherosclerosis of the ipsilateral internal carotid artery, leading to a temporary reduction in blood flow to the eye. This condition typically presents as a brief episode of monocular vision loss, often described as a "curtain" coming down over one eye, lasting minutes before vision returns to normal. The most frequent underlying cause is carotid artery disease, specifically atherosclerosis, where plaque builds up in the carotid arteries and fragments can break off and travel to the eye 1. Other potential causes include:
- Carotid artery stenosis or occlusion
- Dissection
- Arteritis
- Radiation-induced arteriopathy
- Arterial embolism
- Cardiogenic embolism
- Atheroembolism
- Hypotension
- Intracranial hypertension
- Glaucoma
- Migraine
- Vasospastic or occlusive disease of the ophthalmic artery 1. Since amaurosis fugax can be a warning sign of an impending stroke, it should be treated as a medical emergency requiring prompt evaluation with carotid imaging, cardiac assessment, and appropriate blood tests. Treatment typically focuses on addressing the underlying cause, which may include antiplatelet therapy, statins, blood pressure management, and in some cases with significant carotid stenosis, surgical interventions like carotid endarterectomy may be necessary. The risk of subsequent stroke is related to the presence of other risk factors such as hypertension, hypercholesterolemia, diabetes, and cigarette smoking 1.
From the Research
Causes of Amaurosis Fugax
The usual cause of amaurosis fugax is:
- Transient hypoperfusion of the eye, caused by thromboemboli from atherosclerotic carotid arteries 2, 3, 4, 5
- Thromboembolism from carotid arteries is a risk factor for cerebral infarction 2
- Atheromatous plaque at the carotid bifurcation in the neck liberating emboli or causing a temporary reduction in carotid and retinal blood flow 3, 5
- Embolus from the aorta or the heart, or localized thrombosis of vessels of the optic nerve or the retina 4
Pathoetiology
Amaurosis fugax can be divided into four identifiable symptom complexes, each with its underlying pathoetiology: