What is the treatment for Central Retinal Artery Occlusion (CRAO)?

Treatment for Central Retinal Artery Occlusion (CRAO)

Immediate emergency department referral for thrombolytic therapy consideration within 4.5 hours of symptom onset is the primary treatment for central retinal artery occlusion (CRAO). 1

Immediate Triage and Assessment

• CRAO is an ocular emergency equivalent to cerebral stroke requiring immediate action
• When diagnosed in any outpatient setting (ophthalmology, optometry, neurology, primary care):
  • Immediate triage to emergency department without delay for further outpatient evaluation
  • Do not waste time with ineffective office-based treatments 2

Emergency Department Protocol

1. Parallel workflow upon arrival:

   • Immediate ophthalmological examination to confirm diagnosis
   • Structured neurological assessment (National Institutes of Health Stroke Scale)
   • CT brain without contrast to rule out hemorrhage
   • Screen for giant cell arteritis (GCA) in suspicious cases 2, 1

2. Thrombolytic therapy consideration:

   • Intravenous tPA (Alteplase) is the primary treatment for patients presenting within 4.5 hours
   • Dosage: 0.9 mg/kg with 10% given over 1 minute and remainder over 59 minutes
   • Meta-analysis shows 50% rate of clinical recovery when treated within 4.5 hours 2, 1

Time-Critical Nature

• Treatment efficacy is highly time-dependent:
  • Experimental models show irreversible damage occurs after 90 minutes of complete occlusion
  • Clinical improvement may still be possible with treatment up to 4.5-6 hours after onset
  • The EAGLE trial failure was attributed to late treatment (mean 13 hours after onset) 2, 3

Alternative Treatments

• Hyperbaric oxygen therapy (HBOT):

  • May be considered if tPA is contraindicated or unavailable
  • Should be initiated as soon as possible, ideally within 24 hours
  • Can increase oxygen delivery to ischemic retina until reperfusion occurs 3, 4

• Intra-arterial thrombolysis:

  • May be considered in specialized centers with endovascular capabilities
  • Involves selective catheterization of the ophthalmic artery
  • Technical challenges include small vessel size and increased risk with atherosclerosis 2

Ineffective Treatments to Avoid

• The following traditional treatments have not been proven effective and should not delay definitive care:
  • Anterior chamber paracentesis
  • Ocular massage
  • Topical intraocular pressure-lowering agents
  • Sublingual isosorbide dinitrate
  • Hemodilution 2, 1, 5

Secondary Prevention

• Comprehensive vascular workup:
  • Carotid imaging to identify stenosis
  • Transthoracic echocardiography for cardioembolic sources
  • Ambulatory cardiac rhythm monitoring for atrial fibrillation
  • Aggressive control of vascular risk factors (hypertension, diabetes, hyperlipidemia) 1

Prognosis

• Natural history of untreated CRAO is poor:
  • Only 17.7% of untreated patients achieve functional visual recovery
  • Nearly 80% have "count fingers" vision or worse at follow-up
  • Unilateral vision loss increases risk of falls and functional dependence 2

Key Pitfalls to Avoid

1. Delayed recognition and referral - CRAO is a true emergency requiring immediate action
2. Wasting time with ineffective treatments - Do not delay transfer for ocular massage or other unproven therapies
3. Missing arteritic CRAO - Always screen for giant cell arteritis, as immediate steroid therapy is needed to preserve vision in the contralateral eye
4. Failure to evaluate for underlying vascular disease - CRAO patients have high risk of subsequent stroke and cardiovascular events 2, 1