retinal artery occlusion

Etiology

• thromboembolism from the heart, carotid artery or temporal artery
• Susac syndrome
• risk factors:
  • atherosclerosis: carotid artery stenosis, coronary artery disease
  • hypertension
  • dyslipidemia
  • endocarditis, atrial fibrillation, atrial myxoma

Epidemiology

• 50-70 years of age

Pathology

• embolism or thrombosis in the ophthalmic artery

Clinical manifestations

• sudden transient or permanent monocular visual impairment
• painless
• often occurs in early morning
• clear cornea
• red eye
• pupil may be dilated & poorly reactive to light
  • afferent pupillary defect
  • may react to light in contralateral eye

Laboratory

• blood cultures if endocarditis suspected

Diagnostic procedures

• funduscopy:
  • pale fundus
  • attenuation of post-occulsion retinal arteries
  • infarcted retina is pale & masks the underlying choroidal circulation except at the macula, where the thinness of the tissue allows it to be seen resulting in the so-called 'cherry-red spot'
  • 'box-car' effect may be seen in venous drainage
  • emboli visible in 60%
• echocardiogram vs transesophageal echocardiogram
  • atrial myxoma, endocarditis.

* image (funduscopy)

Complications

• permanent visual loss may occur within 100 minutes of onset
• associated with 24% risk of ischemic stroke
  • 5% risk of ischemic stroke within 30 day window of central retinal artery occlusion

Differential diagnosis

• temporal arteritis

Management

• place patient in supine position
• reduce intraocular pressure with ocular digital massage
• intravenous mannitol
• oral acetazolamide
• oral nitrates
• referral to an ophthalmologist
• prognosis
  • better vision at presentation predicts better prognosis

More general terms

• retinal vascular occlusion
• arterial disease
• ischemia

More specific terms

• central retinal artery occlusion (CRAO)
• Hollenhorst plaque

Additional terms

• central retinal artery (Zinn artery)