From the Guidelines
The workup for unilateral central retinal artery occlusion (CRAO) should be approached as a medical emergency requiring immediate evaluation and management. Initial assessment should include a thorough history and physical examination, with particular attention to cardiovascular risk factors and symptoms of giant cell arteritis, as recommended by the American Heart Association 1. Immediate ophthalmologic consultation is essential. Laboratory tests should include complete blood count, erythrocyte sedimentation rate, C-reactive protein, lipid profile, hemoglobin A1c, and coagulation studies.
Key Components of the Workup
- Imaging studies should include:
- Carotid duplex ultrasonography to evaluate for carotid stenosis
- Echocardiography (both transthoracic and transesophageal) to identify cardiac sources of emboli
- Brain MRI/MRA to assess for concurrent stroke or other vascular abnormalities
- For patients over 50 years with elevated inflammatory markers, temporal artery biopsy should be considered to rule out giant cell arteritis, as suggested by the Ophthalmology preferred practice pattern 1
- If giant cell arteritis is suspected, high-dose corticosteroids (prednisone 1mg/kg/day) should be initiated immediately, even before biopsy confirmation
Acute and Secondary Management
- Acute management may include ocular massage, anterior chamber paracentesis, and breathing into a paper bag to increase carbon dioxide levels and potentially dilate retinal vessels, though evidence for these interventions is limited 1
- Secondary prevention typically involves antiplatelet therapy (aspirin 81-325mg daily) and aggressive management of cardiovascular risk factors
- The use of hyperbaric oxygen therapy (100% oxygen over 9 hours) has demonstrated efficacy over observation alone in several small randomized trials 1 This comprehensive workup is crucial as CRAO represents ocular stroke and indicates significant risk for cerebral ischemic events, requiring prompt evaluation to prevent further vascular complications, with up to 24% of patients having concurrent cerebrovascular accident on diffusion weighted MRI 1.
From the Research
Workup for Unilateral Central Retinal Artery (CRA) Occlusion
The workup for unilateral central retinal artery (CRA) occlusion involves a combination of medical and mechanical means to reestablish retinal circulation and improve visual outcome. The following steps are considered:
- Ocular massage
- Sublingual isosorbide dinitrate
- Intravenous acetazolamide
- Intravenous mannitol or oral glycerol
- Anterior chamber paracentesis
- Intravenous methylprednisolone followed by streptokinase
- Retrobulbar tolazoline 2
- Local intra-arterial tissue plasminogen activator (tPA) 3, 4, 5
- Intra-retinal arterial cannulation with tPA using a microneedle 3
- Endovascular intervention via local intra-arterial fibrinolysis with alteplase 4
- Intravenous thrombolysis therapy and etiologic workup based on current stroke protocols 6
Etiologic Workup
Etiologic workup is essential to identify the underlying cause of CRAO, which can include:
- Embolic sources such as carotid stenosis, carotid dissection, cardioembolism, and giant cell arteritis 6
- Systemic conditions such as hypercholesterolemia, rheumatoid arthritis, and atrial fibrillation 4, 6
- Primary antiphospholipid antibody syndrome 2
Timing of Treatment
The timing of treatment is crucial, with better outcomes observed when treatment is initiated within a shorter duration of symptom onset: