What are the recommended evaluations and treatments for sudden visual disturbances in one eye?

Sudden Visual Disturbance in One Eye: Emergency Evaluation and Management

Sudden monocular visual loss—whether transient or persistent—must be treated as a medical emergency requiring immediate referral to an emergency department affiliated with a stroke center within 24 hours of symptom onset. 1

Immediate Triage and Referral

Send the patient immediately to the nearest emergency department with stroke center capabilities or rapid-access TIA clinic—do not delay for additional outpatient testing. 1 The risk of stroke is highest within the first 7 days after retinal ischemia, with rates of 2.7% at 1 day, 5.3% at 3 days, and 11.5% at 14 days. 1 Up to 24% of patients with central or branch retinal artery occlusion have concurrent cerebrovascular accident on diffusion-weighted MRI. 1

Critical Time-Sensitive Actions:

• Call ahead to the stroke center to alert them that "a stroke patient is on the way" 1
• Provide a referral note indicating "Ocular TIA" or "Ocular Stroke" 1
• Do not attempt further testing yourself—ophthalmologists should not delay transfer to perform additional diagnostic workup 1

Giant Cell Arteritis Screening (Age >50 Years)

Before transfer, immediately screen for giant cell arteritis (GCA) symptoms, as this represents an ophthalmologic emergency requiring immediate corticosteroid therapy to prevent blindness in the fellow eye. 1

Key GCA Red Flags to Assess:

• New-onset persistent temporal headache 1
• Jaw or tongue claudication 1
• Constitutional symptoms: weight loss >2 kg, fever, fatigue, night sweats 1
• Polymyalgia rheumatica symptoms 1
• Scalp tenderness or thickened temporal artery 1

If GCA is suspected based on clinical features, order ESR and CRP immediately and initiate high-dose IV corticosteroids BEFORE diagnostic confirmation. 1, 2 The recommended regimen is IV methylprednisolone 250 mg every 6 hours (or 1000 mg daily) for 3-5 days, plus daily aspirin. 1, 2 Delaying corticosteroid therapy when visual loss is present is the strongest risk factor for permanent bilateral blindness. 1

Emergency Department Evaluation Protocol

Once at the stroke center, the following urgent workup should occur within 24 hours: 1

Neuroimaging (Preferred within 24 hours):

• Brain MRI with diffusion-weighted imaging (DWI) is the preferred modality to detect silent brain infarctions present in 19-25% of retinal artery occlusion patients 1
• Head CT if MRI unavailable 1

Vascular Imaging:

• Noninvasive cervicocephalic vessel imaging (MRA, CTA, or carotid ultrasound/transcranial Doppler) to identify carotid stenosis, which is found in up to 70% of symptomatic retinal artery occlusion patients 1

Laboratory Studies:

• Complete blood count with platelets 1
• Chemistry panel, hemoglobin A1C, fasting lipid panel 1
• Prothrombin time/partial thromboplastin time 1
• ESR and CRP in all patients >50 years to screen for GCA 1

Cardiac Evaluation:

• Electrocardiography immediately 1
• Prolonged cardiac monitoring (telemetry or Holter) if etiology unclear 1
• Echocardiography (at least transthoracic) to identify cardioembolic sources 1

Acute Treatment Considerations

For Non-Arteritic Retinal Artery Occlusion:

Evidence for acute interventions to restore vision is limited and controversial. 1 However:

• IV tissue plasminogen activator (tPA) may be considered if presenting within 4.5 hours of symptom onset, with observational data showing 50% clinical recovery when treated within this window 1
• Hyperbaric oxygen therapy (100% oxygen over 9 hours) has demonstrated efficacy over observation in small randomized trials 1, 3

For Arteritic (GCA-Related) Occlusion:

Immediate IV methylprednisolone is mandatory to prevent fellow eye involvement, which occurs in up to 50% of untreated patients within days. 1, 4 Temporal artery biopsy should be performed within 3-5 days but should not delay corticosteroid initiation. 1, 2

Secondary Stroke Prevention

All patients with retinal ischemia require aggressive secondary stroke prevention, as they have the same cardiovascular risk as patients with cerebral TIA. 5

• Antiplatelet therapy (aspirin or dual antiplatelet therapy depending on vascular findings) 3, 5
• Carotid endarterectomy or stenting if significant stenosis identified 1, 5
• Optimization of vascular risk factors: hypertension, diabetes, hyperlipidemia 1, 3
• Smoking cessation 1

Monitoring for Ocular Complications

Panretinal photocoagulation (PRP) with or without anti-VEGF therapy is indicated if iris or retinal neovascularization develops, which can lead to neovascular glaucoma. 1, 3 Intravitreal anti-VEGF agents may be used off-label to supplement PRP in acute cases. 1, 3

Common Pitfalls to Avoid

• Do not assume reperfusion eliminates stroke risk—even if vision returns, the patient still requires urgent stroke workup as concurrent brain infarction may be present 3
• Do not wait for ophthalmology consultation before ED referral—only one-third of ophthalmologists currently transfer these patients emergently despite guideline recommendations 1, 3
• Do not delay corticosteroids for biopsy confirmation in suspected GCA—temporal artery biopsy remains diagnostic even weeks after steroid initiation 1
• Do not dismiss transient visual loss on awakening in young patients with crowded discs—this may represent a benign autoregulatory phenomenon rather than embolic disease, particularly in women under 50 with cup-to-disc ratio ≤0.2 6