Central retinal artery occlusion

• CRAO is a rare event with an incidence of approximately 1 to 10 in 100,000. 
•  Symptomatic BRAO is even less common. 
• Demographic characteristics of patients with CRAO and BRAO are consistent with those seen for other vascular disorders. 
•  The mean age of patients is between 60 and 65 years More than 90 percent of patients with CRAO and BRAO are over the age of 40 years 
• Men are more commonly affected than women. 
•  Hypertension, smoking, and diabetes are more prevalent among patients with retinal artery occlusion compared with controls. 
•  Patients presenting with CRAO often have a previously undiagnosed vascular risk factor (eg, hyperlipidemia, hypertension)[1]

Causes

• Carotid artery atherosclerosis 
• Cardiogenic embolism 
• Small artery disease 
• Other vascular disease
•  Carotid artery dissection 
• Fibromuscular dysplasia 
• Moyamoya disease 
• Radiation injury 
• Fabry disease 
• Vasospasm/migraine? 
• Hematologic disease
•  Inflammatory disease
•  Giant cell arteritis. Approximately 2 percent of older adult patients with CRAO have underlying GCA. Vision loss in GCA is usually due to ischemic optic neuropathy; however, 10 percent of patients who lose vision from GCA do so on the basis of CRAO. While an unusual cause of CRAO, it is important to diagnose GCA because of its implications for prognosis and treatment. GCA should be strongly considered as a potential cause of CRAO in any patient over the age of 50 years who does not have visible retinal emboli. 
• Susac syndrome 
• Other: Lupus, PAN, sarcoidosis, eosinophilic granulomatosis with polyangiitis, GPA[1]

Clinical Course

Exam

• Carotid artery imaging – A carotid duplex ultrasound, cervical magnetic resonance imaging, or computed tomographic angiography will, in most cases, be the first test ordered, as carotid atherosclerosis is the most common cause of CRAO and BRAO
• Cardiac evaluation – In most cases, a transthoracic echocardiogram is sufficient to screen for structural cardiac disease that requires anticoagulation.
•  A baseline electrocardiogram (ECG) 
• Hypercoagulable testing – Hypercoagulable testing should be performed in individuals who have suggestive histories (prior thrombosis, miscarriage, or family history), as well as in individuals with an otherwise negative work-up. 
• A significant number of cases (up to 20 percent in older and 50 to 67 percent in younger patients) have no identified etiology after extensive diagnostic work-up.[1]

APL and CRAO