Laboratory Studies
Laboratory studies may be helpful in determining the etiology of central retinal artery occlusion (CRAO) but do not affect ED treatment. These studies may include the following:
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CBC count to evaluate anemia, polycythemia, and platelet disorders
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Erythrocyte sedimentation rate (ESR) for inflammatory endarteritis in the absence of another etiology
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Fibrinogen level, antiphospholipid antibodies, prothrombin time (PT), activated partial thromboplastin time (aPTT), and serum protein for coagulopathies
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Cholesterol, triglycerides, and lipid panel to evaluate for atherosclerotic disease
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Blood cultures for bacterial endocarditis and septic emboli
Sickle cell disease may also cause RAO and may warrant workup for those at risk.
Imaging Studies
Imaging studies may be helpful in determining the etiology of CRAO but do not affect ED treatment. These studies do not need to be performed emergently in the ED.
Echocardiography is not necessarily an ED test but can be used to evaluate valvular disease, wall motion abnormalities, mural thrombi, and vegetations that may cause septic emboli.
Evaluation of the carotids with carotid Doppler ultrasonography, magnetic resonance angiography (MRA), or computed tomography angiography can be used to evaluate atherosclerotic disease.
Other Tests
Perform an ECG to evaluate for possible atrial fibrillation (24-hour Holter monitor may be necessary if arrhythmia is suspected but not detected on ECG testing).
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The cherry red spot of central retinal artery occlusion.
