Central Retinal Artery Occlusion (CRAO)

Central Retinal Artery Occlusion (CRAO)

Etiology

Common causes :

• Atherosclerotic thrombosis, systemic diseases, trauma, blood coagulation disorder, inflammation, infectious disease or connective tissue disease

Occasionally seen in :

• Retrobulbar injection, retinal detachment or orbital operation

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Clinical Manifestation

• Symptoms

  • Sudden painless vision loss of one eye

• Signs

  • Direct light reflex disappear, indirect light reflex normal
  • Retinal edema, cherry-red spot
  • Retina artery narrow, mild hemorrhage

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Comparison of Eye Fundus

• Normal eye fundus
• CRAO

![[Central Retinal Artery Occlusion CRAO-1745140572398.webp]]

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FFA of CRAO

21s after injection of fluorescein, a complete absence in filling central retinal artery, except segment of inferior temporal branch

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Treatment

• *Target to reestablish retinal circulation & function

• *Timing: the earlier the better

• *Drugs: vasodilator (tropical or systemic) + reduce IOP

  1. Vasodilator : antispasm or pushing thrombus to the smaller branchZ

• 2. Oxygen inhalation:

  • Mixture of 95% oxygen & 5% carbon dioxide

• 3. Reducing IOP:Z

  • (1) Massage
  • (2) Anterior chamber paracentesis
  • (3) Diamox 500mg st; 250mg bid
  • NaHCO3 500mg bid ~ tid

• 4. Fibrolytic enzyme: for patients suspect of thrombosis

  • Urokinase 5 000 ~ 10 000U iv qdZ

Prognosis

• Depends on site, severity and duration.
• Irreversible after 4 hrs