Central Retinal Artery Occlusion (CRAO) Clinical Presentation

Updated: Sep 06, 2018
  • Author: Robert H Graham, MD; Chief Editor: Andrew G Lee, MD  more...
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Presentation

History

The most common presenting complaint of central retinal artery occlusion (CRAO) is acute, unilateral, persistent, painless vision loss in the range of counting fingers to light perception in 90% of patients. The clinician should consider an ophthalmic artery occlusion if the visual acuity is worse or if the cherry red spot is absent (indicating possible choroidal as well as retinal artery occlusive disease).

Some patients with CRAO reveal a history of amaurosis fugax (transient vision loss lasting seconds to minutes but that may last up to 2 hours), which may result from transient CRAO. The vision usually returns to baseline after an episode of amaurosis fugax.

The clinician should inquire about the symptoms of temporal arteritis in older patients (eg, headache, jaw claudication, scalp tenderness, proximal muscle and joint aches, anorexia, weight loss, fever).

The past medical history should include any medical problems that could predispose to embolus formation (eg, atrial fibrillation, endocarditis, atherosclerotic disease, hypercoagulable state). Other predisposing factors include prolonged direct pressure to the globe during drug-induced stupor or improper positioning during face-down surgical procedures. The physician should also inquire about any illicit drug history.

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Physical

Determine the degree of vision loss (eg, no light perception, hand movement, counting fingers).

Ocular examination includes the following:

  • Check for a relative afferent pupillary defect (rAPD).
  • Perform an optic nerve examination to look for signs of temporal arteritis (eg, concomitant ischemic optic neuropathy or cilioretinal artery occlusion). Critical signs include the rAPD and pale/swollen optic nerve (pallid edema) with splinter hemorrhages.
  • Cherry-red spot and a ground-glass retina may take hours to develop.
  • The funduscopic findings typically resolve within days to weeks of the acute event, sometimes leaving a pale optic disc as the only physical finding.
  • Emboli can be seen in about 20% of patients with CRAO.
  • Boxcar segmentation can be seen in both arteries and veins. This is a sign of severe obstruction.
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Causes

Emboli dislodged from the carotid artery are the most common cause of CRAO, from either an unstable atherosclerotic plaque or a cardiac source.

The probable causes of CRAO vary depending on the age of the patient. A detailed analysis of comorbid disease is necessary to elucidate the cause of the acute visual loss. See the following:

  • Systemic hypertension, seen in two-thirds of patients
  • Diabetes mellitus
  • Cardiac valvular disease, seen in a quarter of patients
  • Cardiac anomalies, such as patent foramen ovale (PFO)
  • Embolism, as follows:
    • Cholesterol is the most common type, but it can also be from calcium, bacteria, or talc from intravenous drug use.
    • This is associated with poorer visual acuity and higher overall morbidity and mortality.
    • Emboli from the heart are the most common cause of CRAO in patients younger than 40 years.
  • Atherosclerotic changes, as follows:
    • Carotid atherosclerosis is seen in 45% of cases of CRAO, with 60% or greater stenosis in 20% of cases. Callizo et al found that ipsilateral carotid stenosis was the most significant risk factor for CRAO. [12]
    • Atherosclerotic disease is the leading cause of CRAO in patients aged 40-60 years.
    • Chang et al have found an increased risk of acute coronary syndrome (indicative of coronary atherosclerosis) in patients with retinal arterial occlusions. [13]
  • Amaurosis fugax preceding persistent vision loss suggests transient CRAO, branch retinal artery occlusion (BRAO), or temporal arteritis.
  • A hypercoagulable state, such as in patients with sickle cell anemia, polycythemia, or antiphospholipid syndrome or in those taking oral contraceptives, is a common etiology of CRAO in patients younger than 30 years.
  • Giant cell arteritis, as follows:
    • Giant cell arteritis should be considered in elderly patients
    • Giant cell arteritis may produce CRAO, cilioretinal artery occlusion, ischemic optic neuropathy, or a combination of these findings
  • Giant cell arteritis needs to be treated immediately with corticosteroids to preserve vision in the fellow eye.
  • Collagen vascular disease
  • Polyarteritis nodosa
  • Increased intraocular pressure due to glaucoma
  • Hydrostatic arterial occlusion
  • Iatrogenic: With the increasing popularity of cosmetic facial filler injections, Chen et al and Carle et al report that these injections are a cause of retinal artery occlusions. [14, 15] Other associations with CRAO, such as extracapsular cataract extraction with retrobulbar anesthesia, [16] strangulation, [17] or injection of stem cells for scalp baldness, [18] have been published.
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Complications

Patients with CRAO may develop a cerebrovascular accident due to secondary emboli. Park et al found that patients with CRAO had a significantly increased risk for stroke and acute myocardial infarction, particularly during the first week following CRAO. [19] Further emboli could travel to the same or contralateral eye, resulting in further visual loss. Ocular neovascularization, including neovascular glaucoma, occurs in approximately 15% of patients with CRAO, especially in those with diabetes mellitus, type 2. [20]

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