Is amaurosis fugax a type of transient ischemic attack (TIA)?

From the Guidelines

Yes, amaurosis fugax is a specific type of transient ischemic attack (TIA). It presents as a temporary loss of vision in one eye, often described as a "curtain" or "shade" coming down over the visual field, typically lasting for a few minutes. This occurs when blood flow to the retina is temporarily blocked, usually due to an embolus from the carotid artery or heart. Like other TIAs, amaurosis fugax serves as an important warning sign of stroke risk and requires prompt medical evaluation. Patients experiencing this symptom should seek immediate medical attention as it indicates a significant risk for future stroke. Management typically includes a thorough cardiovascular workup, carotid imaging, and appropriate preventive therapy such as antiplatelet medications (aspirin 81-325 mg daily, clopidogrel 75 mg daily, or combination therapy), statins, blood pressure control, and possibly carotid revascularization if significant stenosis is identified. Lifestyle modifications including smoking cessation, diet improvement, and regular exercise are also essential components of treatment. The temporary nature of the vision loss distinguishes it from permanent visual impairment caused by retinal artery occlusion.

Key Points

• Amaurosis fugax is a type of TIA that affects the eye, causing temporary vision loss in one eye.
• It is often caused by a temporary reduction in blood flow to the retina, usually due to an embolus from the carotid artery or heart.
• Prompt medical evaluation is necessary to assess the risk of future stroke and to initiate preventive therapy.
• Management includes a thorough cardiovascular workup, carotid imaging, and preventive therapy such as antiplatelet medications, statins, and lifestyle modifications.

Evidence-Based Recommendations

The most recent and highest quality study, 1, recommends urgent workup for patients with amaurosis fugax, as the risk of stroke is highest within the first 7 days and remains elevated for 30 days. Additionally, the study suggests that patients with symptomatic retinal artery occlusion should be referred for an urgent evaluation within 1 week of onset. Other studies, such as 1 and 1, also support the importance of prompt medical evaluation and management of amaurosis fugax to reduce the risk of future stroke.

Clinical Implications

The diagnosis of amaurosis fugax as a type of TIA has significant clinical implications, as it requires prompt medical attention and initiation of preventive therapy to reduce the risk of future stroke. The temporary nature of the vision loss distinguishes it from permanent visual impairment caused by retinal artery occlusion, and early recognition and treatment can help prevent long-term visual and neurological damage.

From the Research

Definition and Classification

• Amaurosis fugax (AF) is a term used to denote momentary visual loss from transient retinal ischemia 2.
• Transient ischemic attack (TIA) is defined as a transient episode of neurological dysfunction resulting from focal brain, spinal cord, or retinal ischemia, without associated infarction 2.
• AF is considered a type of TIA, as it is a transient ischemic episode that affects the retina 2, 3, 4.

Clinical Characteristics and Outcome

• The clinical characteristics and prognosis of patients with AF due to suspected transient retinal ischemia have been studied, and it was found that the risk of ischemic stroke is a concern 5.
• The prevalence of significant carotid stenosis in patients with AF is higher than in stroke patients, and associations with vascular risk factors and vasculitis have been reported 6.
• Studies have compared the clinical associations, arteriographic findings, and long-term outcome of patients with AF and those with focal cerebral ischemia (TIAs), and found differences in the cumulative rates of cerebral infarction and recurrent TIAs 3, 4.

Management and Treatment

• The management of all TIAs, whether cerebral or retinal, is similar and should focus on stroke prevention strategies 2.
• General measures include the initiation of appropriate antiplatelet therapy, encouraging a healthy lifestyle, and managing traditional risk factors, such as hypertension, dyslipidemia, and diabetes 2.
• Specific management measures 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 2.