What is the management for an embolic stroke causing unilateral vision loss?

Management of Embolic Stroke Causing Unilateral Vision Loss

Patients with embolic stroke causing unilateral vision loss (retinal artery occlusion) must be immediately referred to the nearest emergency department affiliated with a stroke center within 24 hours of symptom onset, as these represent true "eye strokes" with high risk of subsequent cerebral stroke and acute coronary events. 1, 2

Immediate Triage and Referral

• Send the patient immediately to a certified stroke center emergency department with a note indicating "Ocular Stroke" or "Ocular TIA," and call ahead to warn them "a stroke patient is on the way." 1
• Do not delay emergency referral to obtain further outpatient evaluation or institute other treatments. 2
• Eye care providers should serve as "gate-keepers" to confirm the diagnosis of retinal vascular ischemia (CRAO, BRAO, or transient monocular vision loss) before urgent referral. 1

Acute Treatment Window (Within 4.5 Hours)

• For patients presenting within 4.5 hours of symptom onset, intravenous tissue plasminogen activator (tPA) may be considered at the standard dose of alteplase 0.9 mg/kg. 2, 3
• Brain CT without contrast must be performed immediately before thrombolysis to rule out hemorrhagic stroke. 2
• Studies show 54% of CRAO patients receiving IV tPA within 4.5 hours had no symptomatic intracranial or ocular hemorrhage, with most demonstrating visual benefit when treated very early. 3

Critical Diagnostic Workup in Emergency Setting

The following tests should be obtained immediately during a 23-hour observation period with cardiac monitoring, following the standard American Heart Association/National Stroke Association "stroke protocol": 1

• Brain MRI with diffusion-weighted imaging (DWI-MRI) to identify concurrent silent cerebral infarctions, which occur in 27-76.4% of CRAO patients and 11.8-30.8% of transient monocular vision loss patients. 1
• Vascular imaging (MRA or CTA) to assess for internal carotid artery stenosis ≥50%, which is found in up to 70% of symptomatic CRAO patients. 1, 2
• Echocardiography (at minimum transthoracic; transesophageal if it will alter management) to identify cardiac sources of emboli. 1
• ESR and CRP to screen for giant cell arteritis, particularly in patients over 50 years of age. 1, 2

The presence of silent cerebral infarctions on DWI-MRI identifies the subgroup at very high risk of recurrent stroke requiring immediate treatment. 1

Hospitalization Criteria

Hospitalize patients if they present within 72 hours AND have any of the following: 1

• Abnormal brain DWI-MRI showing acute cerebral infarction(s)
• Large artery atherosclerosis (e.g., internal carotid artery stenosis)
• Abnormal cardiac evaluation
• Recurrent episodes (crescendo TIAs)
• Inability to provide expedited outpatient follow-up

If no embolic cause requiring immediate treatment is identified, the patient can be discharged after 24 hours with optimal secondary prevention. 1

Secondary Stroke Prevention (All Patients)

All patients must be discharged with the following secondary prevention measures: 1

• Antiplatelet therapy (antithrombotic agent) initiated immediately. 1, 2
• Statin therapy for hyperlipidemia. 1
• Blood pressure control optimization. 1
• Outpatient neurology follow-up with stroke expertise within 2 weeks to review workup results and optimize prevention. 1

Special Consideration: Giant Cell Arteritis

• For suspected arteritic CRAO (giant cell arteritis), immediate high-dose systemic corticosteroid therapy is mandatory to preserve vision in the contralateral eye, even before confirmatory testing. 1, 2
• This applies specifically to patients over 50 years with systemic symptoms suggestive of GCA. 1

Monitoring for Neovascular Complications

• Patients with retinal artery occlusion have increased risk for iris and retinal neovascularization due to ischemia. 1
• Panretinal photocoagulation (PRP) is recommended for patients who develop iris or retinal neovascularization. 1, 2
• Patients with greater ischemia require closer and more frequent follow-up. 1

Critical Timing and Risk Stratification

• The risk of subsequent cerebral stroke is maximum within the first few days after retinal arterial ischemia, with the highest risk in the first 7 days and remaining elevated for 30 days. 1, 2
• Up to 24% of patients with acute retinal artery occlusion have concurrent cerebrovascular accident on DWI-MRI despite having no neurologic symptoms. 2
• These patients also have major risk of acute coronary events, not just stroke. 1

Common Pitfalls to Avoid

• Do not treat retinal artery occlusion as a purely ophthalmologic problem—it is a medical emergency equivalent to acute cerebral ischemia. 4
• Do not delay emergency referral for same-day ophthalmology consultation—the eye care provider should confirm the diagnosis and immediately send the patient to the stroke center. 1
• Do not assume patients with transient monocular vision loss are lower risk—they still have 11.8-30.8% rate of silent cerebral infarctions and require urgent stroke workup. 1
• Do not discharge patients without arranging urgent neurology follow-up, as optimal secondary prevention requires specialist review within 2 weeks. 1