From the Guidelines
The immediate management of central retinal artery occlusion (CRAO) should focus on emergency measures to restore retinal blood flow, with interventions most effective within the first 4-6 hours of symptom onset, as retinal tissue suffers irreversible damage after 90-100 minutes of ischemia 1.
Key Interventions
- Ocular massage by applying firm pressure to the eye through closed eyelids for 5-15 seconds, then releasing for 5 seconds, repeating for several minutes, to dislodge emboli by creating a pressure gradient.
- Anterior chamber paracentesis, performed by an ophthalmologist, involves removing a small amount of aqueous humor to reduce intraocular pressure.
- Breathing into a paper bag or carbogen therapy (95% oxygen, 5% carbon dioxide) may induce vasodilation.
- High-flow oxygen therapy (10-15 L/min) via face mask should be administered to increase oxygen delivery to the ischemic retina.
- Intravenous acetazolamide (500 mg) or oral acetazolamide (500 mg) can be given to reduce intraocular pressure.
- Sublingual nitroglycerin (0.4 mg) may help through vasodilation.
Underlying Conditions
Patients should be evaluated for underlying conditions like carotid stenosis, cardiac emboli, or giant cell arteritis that may have caused the occlusion, with a careful systemic evaluation guiding therapy 1.
Timing and Referral
Immediate ophthalmology consultation is essential, and patients should be referred promptly to a stroke center for a medical evaluation, as the risk of ischemic stroke is high during the first 1 to 4 weeks, ranging from 3 - 6% in two studies 1.
From the Research
Immediate Management of Central Retinal Artery Occlusion
The immediate management of central retinal artery occlusion involves several approaches to restore blood flow to the retina and salvage visual acuity. Some of the methods include:
- Intravenous acetazolamide, digital ocular massage, and inhalation of 5% carbon dioxide -- 95% oxygen for ten minutes 2
- Immediate paracentesis of the anterior chamber, digital massage of the globe, and i.v. administration of 500 mg azetazolamide to stimulate retinal reperfusion by lowering the intraocular pressure 3
- Selective intra-arterial fibrinolysis with Urokinase (100,000-1,000 IU) or recombinant plasminogen activator (rtPA) 4, 3
- Intravenous tissue-type plasminogen activator (IV alteplase) within 4.5 hours of symptom onset 5
Timing of Treatment
The timing of treatment is crucial in the management of central retinal artery occlusion. Studies have shown that:
- A good prognosis is to be expected when treatment starts within the first 6-8 hours 4
- Earlier treatment correlates with a higher rate of visual recovery 5
- The worst results were obtained in patients where the mean delay between the appearance of symptoms and initiation of treatment was more than 20 hours 4
Visual Recovery
Visual recovery rates vary depending on the treatment approach and timing. Some studies have reported:
- 44% of patients treated with IV alteplase within 4.5 hours had recovery of visual acuity 5
- 37.3% recovery rate in patients treated with alteplase within 4.5 hours since time last known well 5
- 30% of patients achieved a final visual acuity of 6/10 to 6/6 after intra-arterial fibrinolysis with Urokinase 3