From the Guidelines
Amaurosis fugax is a temporary loss of vision in one eye, typically lasting a few minutes, caused by reduced blood flow to the retina, and it is considered a warning sign of potential stroke that requires immediate medical attention. This condition is often described as a "curtain" or "shade" coming down over the eye. According to the most recent and highest quality study 1, amaurosis fugax commonly results from a small embolus (blood clot or cholesterol plaque) that temporarily blocks the ophthalmic artery or its branches. The risk factors for amaurosis fugax include:
- Hypertension
- Diabetes
- Smoking
- High cholesterol
- Carotid artery disease
When diagnosed, treatment typically involves antiplatelet medications like aspirin (81-325mg daily) or clopidogrel (75mg daily), along with management of underlying conditions. In cases with significant carotid stenosis, surgical interventions like carotid endarterectomy might be recommended 1. The study by 1 recommends that acute retinal and ophthalmic artery occlusions be treated as a medical emergency and be referred immediately to an emergency department or stroke center facility for neurological evaluation because of the increased risk of central nervous system stroke. Anyone experiencing this symptom should seek emergency care as it may precede a more serious stroke. The temporary nature of the vision loss occurs because the blockage often dissolves or moves, restoring blood flow, but the underlying cause must be addressed to prevent more serious vascular events.
From the Research
Definition and Overview of Amaurosis Fugax
Amaurosis fugax is a condition characterized by a sudden, temporary loss of vision in one eye, which typically lasts for a few minutes [(2,3)]. It is considered a medical emergency, particularly for ophthalmologists, as it may indicate an underlying serious condition 2.
Causes and Underlying Conditions
The most common underlying cause of amaurosis fugax is atherosclerosis of the internal carotid artery 3. Other causes include:
- Vasospasm of the internal carotid artery, leading to hypoperfusion 3
- Vasculitis
- Ocular migraines 3
- Systemic lupus erythematosus 3
Clinical Presentation and Diagnosis
Amaurosis fugax can be divided into four identifiable symptom complexes, each with its underlying pathoetiology: embolic, hypoperfusion, angiospasm, and unknown 4. The condition is often characterized by a sudden loss of vision in one eye, which may be accompanied by other symptoms such as headache or neurological deficits [(3,5)].
Treatment and Management
Treatment of amaurosis fugax depends on the underlying cause and may involve urgent therapy, including carotid endarterectomy in cases of significant carotid stenosis [(2,5)]. In some cases, medical management with aspirin, anticoagulants, or other medications may be necessary [(3,5)].
Epidemiology and Incidence
The annual incidence of amaurosis fugax is estimated to be around 8.6 and 6.2 per 100,000 population for men and women, respectively 6. However, the true incidence may be higher, as some cases may go unreported or undiagnosed 6.
Prognosis and Complications
Amaurosis fugax is considered a harbinger of monocular blindness and stroke, particularly if left untreated or if the underlying cause is not addressed 5. Prompt diagnosis and treatment are essential to prevent long-term complications and improve outcomes [(2,3,5)].