Central retinal artery occlusion is a blockage of the main artery to the retina, usually by an embolus from the carotid artery or the heart, causing sudden severe vision loss in one eye. It is a stroke of the eye and needs the same emergency work-up as a brain stroke.
Key symptoms
- Sudden painless loss of vision in one eye
- Vision often reduced to counting fingers or worse
- Sometimes earlier brief episodes of vision loss (amaurosis fugax)
What you find on exam
- Very poor visual acuity in the affected eye
- Relative afferent pupillary defect
- Fundus: pale, swollen retina with a cherry-red spot at the macula
- Narrowed arteries, sometimes a visible embolus
- Carotid bruit, irregular pulse, full neurological exam
Tests
- Urgent ESR and CRP in older patients to rule out giant cell arteritis
- Brain MRI with diffusion imaging
- Carotid imaging, ECG with heart monitoring, echocardiogram
- Glucose, lipids and blood count
Treatment basics
- Send immediately to an emergency stroke center
- Thrombolysis may be considered in some centers within a few hours
- High-dose steroids at once if giant cell arteritis is suspected
- Secondary stroke prevention: antiplatelet, statin, blood pressure control
- Treat carotid disease or atrial fibrillation
Red flags
- Jaw pain with chewing, headache or scalp tenderness (giant cell arteritis)
- Neurological symptoms such as weakness or speech trouble
- Vision loss in the other eye
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Sources: NASEMSO National Model EMS Clinical Guidelines; NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations. Written by Making Synapses. Making Synapses is not affiliated with these organizations.