CRAO is an ophthalmologic emergency — an acute ischemic stroke of the retina — caused by embolic or thrombotic occlusion of the central retinal artery, resulting in sudden, painless monocular vision loss with a high risk of permanent blindness and subsequent cerebrovascular events. [1-2] It should be managed with the same urgency as an acute ischemic stroke. [2-3]
1. History
- Onset and quality: Sudden, painless, monocular vision loss occurring over seconds to minutes; described as a "curtain" or complete blackout of vision in one eye [2-3]
- Timing: Determine exact time of symptom onset — critical for thrombolysis eligibility (≤4.5 hours) [1-2]
- Preceding episodes: Ask about prior transient monocular vision loss (TMVL/"retinal TIA") — episodes of painless blackout lasting minutes suggest prior embolic showers [5]
- Associated symptoms: Headache, jaw claudication, scalp tenderness, temporal tenderness, polymyalgia, weight loss, fever, malaise (screen for giant cell arteritis in patients ≥50) [2-3]
- Neurological symptoms: Lateralizing weakness, speech difficulty, paresthesias (concurrent stroke) [3]
- Important negatives: No pain (pain suggests other diagnoses), no floaters/flashes (retinal detachment), no preceding trauma
2. Alarm Features
- Bilateral vision loss → suspect GCA or systemic vasculitis (1–2% of CRAO) [3]
- Age ≥50 with any GCA symptoms → emergent ESR/CRP and empiric high-dose corticosteroids to protect the fellow eye [3]
- Concurrent neurological deficits → concurrent cerebral stroke (up to 24% have silent brain infarcts on DWI-MRI) [3]
- Optic disc edema with CRAO → suggests combined AION + CRAO, likely vasculitis [2]
- Presentation within 4.5 hours → potential thrombolysis candidate; do not delay transfer [2]
3. Medications
- Acute treatment — thrombolysis: IV alteplase or tenecteplase within 4.5 hours has been investigated but recent RCTs (THEIA, TenCRAOS) have not demonstrated significant benefit over aspirin, with safety concerns including fatal intracranial hemorrhage. The AHA states IV tPA "may be considered" after shared decision-making [1-3][6]
- Aspirin: Reasonable first-line antiplatelet; aspirin 300 mg was the comparator arm in recent trials [1]
- GCA treatment: High-dose IV methylprednisolone (1 g/day × 3 days) followed by oral prednisone when GCA is suspected [3][5]
- Secondary prevention: Antiplatelet therapy (aspirin or clopidogrel), high-intensity statin, antihypertensives as indicated [2-3]
- Anticoagulation: Initiate if atrial fibrillation is detected; CRAO should be classified as "stroke" for CHA₂DS₂-VASc scoring [2]
- Conservative measures NOT recommended: Ocular massage, anterior chamber paracentesis, carbogen, and topical IOP-lowering agents have shown no benefit and may be harmful [3][7]
4. Diet
- No specific acute dietary intervention
- Long-term: Heart-healthy/Mediterranean diet for cardiovascular risk reduction
- Smoking cessation is critical — tobacco use present in ~49% of CRAO patients [2]
5. Review of Systems
- Neurological: Focal weakness, numbness, speech changes, gait disturbance (concurrent stroke)
- Rheumatologic/GCA: Headache, jaw claudication, scalp tenderness, proximal myalgias, fever, weight loss, fatigue [3]
- Cardiovascular: Palpitations (atrial fibrillation), chest pain, dyspnea
- Vascular: Prior TIA, amaurosis fugax, claudication
- Ophthalmologic: Prior episodes of transient vision loss, contralateral eye symptoms
6. Collateral History and Family History
- Confirm exact time of symptom onset from witnesses if patient is uncertain
- Prior cardiac history, known atrial fibrillation, valvular disease, carotid disease
- Recent cosmetic facial filler injections (rising cause of iatrogenic RAO in young women) [5]
- Family history of premature atherosclerotic disease, hypercoagulable states
- In younger patients (<50): history of autoimmune disease, recent neck trauma (carotid dissection), IV drug use [3]
7. Risk Factors
- Hypertension (73% of patients in EAGLE study) [2]
- Ipsilateral carotid artery stenosis (≥70% in up to 37–40%) [2][5]
- Atrial fibrillation — major cardiac embolic source [2][5]
- Diabetes mellitus, dyslipidemia, obesity [2][4]
- Tobacco use (~49%) [2]
- Coronary artery disease, valvular heart disease, heart failure [4][8]
- Male sex, age >60 (incidence rises to 10/100,000 in those >80) [2][9]
- Hypercoagulable states (younger patients) [3]
8. Differential Diagnosis
- Ophthalmic artery occlusion (OAO): More severe (hand motions or worse), no cherry-red spot, diffuse retinal + choroidal ischemia [3][5]
- Central retinal vein occlusion (CRVO): Diffuse intraretinal hemorrhages, dilated tortuous veins — distinct from CRAO [3]
- Anterior ischemic optic neuropathy (AION): Disc edema, altitudinal field defect, less severe acuity loss
- Retinal detachment: Floaters, flashes, curtain-like field loss, visible on fundoscopy
- Vitreous hemorrhage: Sudden vision loss, absent red reflex, no view of fundus
- Optic neuritis: Painful eye movements, younger patients, disc may appear normal acutely
- Giant cell arteritis (arteritic CRAO): Must be excluded in all patients ≥50 [2-3]
- Acute angle-closure glaucoma: Painful, red eye, mid-dilated pupil, elevated IOP
9. Past Medical History
- Prior stroke, TIA, or amaurosis fugax
- Known carotid stenosis or prior endarterectomy
- Atrial fibrillation, valvular disease, recent cardiac procedures
- Diabetes, hypertension, hyperlipidemia
- Hypercoagulable disorders (antiphospholipid syndrome, Factor V Leiden)
- Prior retinal vascular events
- Autoimmune/inflammatory conditions (SLE, vasculitis)
10. Physical Exam
- Visual acuity: Typically 20/200 to counting fingers or worse in >80% of patients; may be near-normal with cilioretinal sparing [2-3]
- Pupil exam: Relative afferent pupillary defect (RAPD) — hallmark finding [1-2]
- Fundoscopy (key findings):
- Retinal whitening/pallor (ischemic edema of inner retina) [2-3]
- Cherry-red spot at the fovea (may be absent early; develops within hours) [2-3]
- Boxcar segmentation of blood in retinal arterioles [2-3]
- Attenuated retinal arteries [1]
- Hollenhorst plaques (cholesterol emboli at vessel bifurcations) — visible <10% of the time [2][4]
- No intraretinal hemorrhages and normal venous caliber (distinguishes from CRVO) [3]
- Normal optic disc (disc edema suggests concurrent AION or GCA) [2]
- Vital signs: Blood pressure (hypertensive crisis), heart rate/rhythm (atrial fibrillation)
- Temporal arteries: Tenderness, nodularity, absent pulse (GCA) [2]
- Carotid auscultation: Bruits
- Neurological exam: Focused stroke assessment (NIHSS) [2]
11. Lab Studies
- ESR, CRP, CBC with platelets — mandatory in all patients ≥50 to evaluate for GCA [2-3]
- Glucose, HbA1c — diabetes screening
- Lipid panel — dyslipidemia assessment
- BMP/CMP — baseline metabolic assessment
- Coagulation studies (PT/INR, aPTT) — if thrombolysis is being considered
- In younger patients or no clear etiology: Antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, anti-β2 glycoprotein), hypercoagulability panel [2-3]
- Troponin — concurrent MI screening
12. Imaging
- CT head without contrast — required emergently to rule out intracranial hemorrhage before thrombolysis consideration [2]
- Brain MRI with DWI — up to 24% of CRAO patients have concurrent silent cerebral infarcts [3]
- Carotid imaging (CT angiography, MR angiography, or carotid duplex ultrasound) — ipsilateral carotid stenosis ≥70% found in up to 40% [2][5]
- Optical coherence tomography (OCT): Inner retinal hyperreflectivity and thickening acutely; aids diagnosis when fundus appears normal early [1-2]
- Fluorescein angiography: Shows delayed/absent retinal perfusion but is time-consuming and usually not necessary acutely [2][5]
- Echocardiography (TTE): Recommended to evaluate for cardioembolic source; TEE if high suspicion and TTE negative [2]
13. Special Tests
- Nonmydriatic fundus photography: Can be obtained in the ED and transmitted via telemedicine for remote ophthalmologic confirmation [2][7]
- OCT angiography: Can demonstrate retinal capillary nonperfusion [2]
- Ambulatory cardiac monitoring (Holter or extended event monitor): AF detection — longer monitoring increases yield [2][10]
- Temporal artery biopsy: When GCA is clinically suspected (do not delay steroids for biopsy) [3]
- NIHSS scoring: Standard stroke assessment [2]
14. ECG
- 12-lead ECG is part of the standard stroke workup — assess for atrial fibrillation/flutter, which is a major embolic source [2][10]
- Look for: AF, atrial flutter, left ventricular hypertrophy, prior MI, ST-T wave changes
- If initial ECG is normal, prolonged cardiac monitoring (7–14 day patch or implantable loop recorder) should be considered, as paroxysmal AF is frequently missed on single-time-point ECG [2][10]
15. Assessment
CRAO is classified as an acute ischemic stroke (CNS infarction) per AHA/ASA definitions. [2] The prognosis for visual recovery is poor: ~80% of patients retain visual acuity of counting fingers or worse, and only ~18% achieve functional visual recovery (≥20/100) with conservative management. [2] Approximately 20% may have some spontaneous improvement from revascularization. [5] The condition carries a stroke risk of up to 25%, highest in the first 2 weeks to 1 month. [3] Iris neovascularization develops in up to 16–20% of cases, typically within 30–60 days, and can lead to neovascular glaucoma. [3][11]
16. Treatment Plan
Acute stabilization (ED)
- Activate stroke code/eye stroke protocol — immediate ophthalmologic confirmation in parallel with neurological assessment and CT head [2]
- Screen for and exclude GCA in patients ≥50 (ESR, CRP, CBC); start empiric IV methylprednisolone if clinical suspicion is high [3][5]
Thrombolysis (evolving evidence — shared decision-making)
- The AHA (2021) suggested IV alteplase may be considered within 4.5 hours after discussion of risks/benefits [2]
- However, the TenCRAOS trial (NEJM, 2026): IV tenecteplase 0.25 mg/kg within 4.5 hours showed no significant benefit over aspirin 300 mg (20% vs 24% achieved ≥20/100 at 30 days), with one fatal intracranial hemorrhage in the tenecteplase group [1]
- The THEIA trial (Lancet Neurology, 2025): IV alteplase within 4.5 hours also showed no significant benefit over aspirin, though the trial was underpowered [6]
Secondary prevention
- Antiplatelet therapy (aspirin ± clopidogrel) [3]
- High-intensity statin [2-3]
- Blood pressure optimization
- Anticoagulation if AF detected [2]
- Carotid endarterectomy for symptomatic ≥50–99% stenosis [3]
Long-term ocular management
17. Disposition
- Immediate transfer to an ED affiliated with a stroke center for all acute symptomatic CRAO [2-3]
- Admission is generally warranted for:
- Concurrent acute cerebral ischemia on imaging
- High-grade carotid stenosis requiring urgent intervention
- Suspected GCA requiring IV corticosteroids and temporal artery biopsy
- Newly detected AF or other cardiac source requiring urgent management
- Thrombolysis candidates (if institutional protocol supports this)
- Observation/expedited outpatient workup may be appropriate if a dedicated rapid-access TIA clinic is available and no high-risk features are identified [5]
- Ophthalmology consultation — urgent for diagnostic confirmation and follow-up planning
- Neurology/stroke consultation — for stroke workup and secondary prevention
18. Follow Up / Return Precautions
- Ophthalmology follow-up within 1–2 weeks, then monthly for at least 3–6 months to monitor for neovascularization (iris NV develops in up to 20%, mean onset ~30–80 days; neovascular glaucoma in ~64% of those with NV) [3][11-12]
- Neurology/stroke follow-up for secondary prevention optimization
- Cardiology referral if AF or structural heart disease detected
- Vascular surgery if significant carotid stenosis identified
Return precautions — instruct patients to seek immediate care for:
- Vision changes in the other eye (GCA risk to fellow eye)
- New neurological symptoms: facial droop, arm/leg weakness, speech difficulty, sudden severe headache
- Eye pain, redness, or halos (neovascular glaucoma)
Expected course: Visual prognosis is generally poor; most patients retain severe monocular vision loss. The primary goal of follow-up is preventing stroke, MI, and ocular neovascular complications. [2-3]
References
1. A Randomized Trial of Tenecteplase in Acute Central Retinal Artery Occlusion. — Ryan SJ, Jørstad ØK, Skjelland M, et al. The New England Journal of Medicine. 2026.
2. Management of Central Retinal Artery Occlusion: A Scientific Statement From the American Heart Association. — Mac Grory B, Schrag M, Biousse V, et al. Stroke. 2021.
3. Retinal and Ophthalmic Artery Occlusions Preferred Practice Pattern®. — Kovach JL, Bailey ST, Kim SJ, et al. Ophthalmology. 2025.
4. Eye Emergencies. — Gelston CD, Deitz GA. American Family Physician. 2020.
5. Retinal Vascular Occlusions. — Scott IU, Campochiaro PA, Newman NJ, Biousse V. Lancet. 2020.
6. Intravenous Alteplase Versus Oral Aspirin for Acute Central Retinal Artery Occlusion Within 4·5 H of Severe Vision Loss (THEIA): A Multicentre, Double-Dummy, Patient-Blinded and Assessor-Blinded, Randomised, Controlled, Phase 3 Trial. — Préterre C, Gaultier A, Obadia M, et al. The Lancet. Neurology. 2025.
7. Updates in Central Retinal Artery Occlusion. — Paddock JE, Bakaeva TV. Journal of Neuro-Ophthalmology : The Official Journal of the North American Neuro-Ophthalmology Society. 2026.
8. Incidence and Risk Factors Associated With Ischemic Cerebrovascular Disease in Patients With Retinal Artery Occlusion: A Systematic Review and Meta-Analysis. — Pothikamjorn T, Charnnarong C, Susantitaphong P, Jariyakosol S. Scientific Reports. 2025.
9. Interventions for Acute Non-Arteritic Central Retinal Artery Occlusion. — Lin JC, Song S, Ng SM, Scott IU, Greenberg PB. The Cochrane Database of Systematic Reviews. 2023.
10. Retinal Artery Occlusions: An Ophthalmological Perspective on Atrial Fibrillation. — De Monte Furtado R, Sukumaran R, Claydon M, et al. Current Medical Research and Opinion. 2025.
11. Population-Based Incidence of Ocular Neovascularization Following Central Retinal Artery Occlusion in Olmsted County, Minnesota. — Tanke LB, Chodnicki KD, Olsen TW, Bhatti MT, Chen JJ. Clinical Ophthalmology. 2021.
12. Chronic Central Retinal Artery Occlusion: Clinical Manifestations, Ocular Neovascular Complications, and Risk of Stroke. — Song JR, Woo SJ. PloS One. 2025.