From the Guidelines
Amaurosis fugax is a medical emergency that requires immediate attention, as it is a warning sign of a potential stroke and can lead to permanent blindness or stroke if left untreated. This condition is characterized by a temporary loss of vision in one eye, often described as a "curtain" or "shade" coming down over the eye, and typically lasts for a few minutes before vision returns to normal 1. It occurs when blood flow to the retina is briefly interrupted, usually due to a small piece of plaque or a blood clot that temporarily blocks an artery supplying blood to the eye. The most common cause is atherosclerosis of the ipsilateral internal carotid artery, but other causes such as carotid artery stenosis or occlusion, dissection, arteritis, and cardiogenic embolism can also be associated with this syndrome 1.
Risk Factors and Treatment
Risk factors for amaurosis fugax include high blood pressure, high cholesterol, diabetes, smoking, and heart disease 1. When experiencing this symptom, it is essential to seek emergency care as it may indicate a serious underlying condition that could lead to a stroke. Treatment typically focuses on addressing the underlying cause and may include blood-thinning medications like aspirin, clopidogrel, or warfarin, as well as medications to control blood pressure and cholesterol 1. In some cases, if there is significant narrowing of the carotid artery, a surgical procedure called carotid endarterectomy might be recommended to remove the plaque buildup. According to a recent study, patients with acute retinal and ophthalmic artery occlusions should be treated as a medical emergency and referred immediately to an emergency department or stroke center facility for neurological evaluation due to the increased risk of central nervous system stroke 1.
Urgent Evaluation and Referral
Urgent evaluation and referral to a stroke center within 1 week of onset is crucial, as the risk of stroke is highest within the first 7 days and remains elevated for 30 days 1. Additionally, silent brain infarction is a frequent finding in unselected patients with acute BRAO/CRAO or amaurosis fugax, and these silent infarctions bear a high risk for future stroke, emphasizing the need for prompt referral to a stroke center 1. Hyperbaric oxygen therapy has demonstrated efficacy in several small randomized trials, and panretinal photocoagulation with or without anti-vascular endothelial growth factor therapy may be recommended for patients who develop iris or retinal neovascularization 1.
Key Takeaways
- Amaurosis fugax is a medical emergency that requires immediate attention
- Risk factors include high blood pressure, high cholesterol, diabetes, smoking, and heart disease
- Treatment focuses on addressing the underlying cause and may include blood-thinning medications and surgical procedures
- Urgent evaluation and referral to a stroke center within 1 week of onset is crucial to reduce the risk of stroke and permanent blindness.
From the Research
Definition and Description
- Amaurosis fugax is a condition characterized by transient monocular blindness, which is a temporary loss of vision in one eye that can last from seconds to minutes 2.
- It is often described as a sudden, painless loss of vision in one eye, which can be partial or complete 3.
Causes and Risk Factors
- The cause of amaurosis fugax is usually an atheromatous plaque at the carotid bifurcation in the neck, which can liberate emboli or cause a temporary reduction in carotid and retinal blood flow 2.
- Risk factors for significant carotid stenosis in patients with amaurosis fugax include male sex, current smoking, diabetes, and previous vasculitis 4.
Diagnosis and Evaluation
- Amaurosis fugax should be investigated and treated in the same way as neurologic transient ischemic attacks (TIAs), with emphasis on rapid detection of extracranial arterial disease, cardiac abnormalities, and haematological disorders 2.
- A comprehensive evaluation of patients with amaurosis fugax should include a detailed history and examination, followed by specific diagnostic studies such as imaging of the brain and extracranial and intracranial blood vessels, cardiac investigations, and serum studies to evaluate for etiological risk factors 5.
Management and Treatment
- The management of amaurosis fugax should focus on stroke prevention strategies, including the initiation of appropriate antiplatelet therapy, encouraging a healthy lifestyle, and managing traditional risk factors such as hypertension, dyslipidemia, and diabetes 5.
- Specific management measures may require the identification of a specific TIA etiology, such as moderate-severe symptomatic extracranial large vessel or intracranial steno-occlusive atherosclerotic disease, aortic arch atherosclerosis, and atrial fibrillation 5.