What is the initial workup for a patient presenting with blurred vision in the emergency department?

Emergency Department Workup for Blurred Vision

Blurred vision in the ED requires immediate triage to identify vision-threatening and life-threatening emergencies, with particular focus on ruling out retinal artery occlusion (ocular stroke), giant cell arteritis, acute angle closure glaucoma, and retinal detachment—all of which demand urgent intervention within hours to prevent permanent vision loss. 1, 2

Immediate Triage and Red Flags

Critical Time-Sensitive Diagnoses to Rule Out First

Retinal artery occlusion (CRAO/BRAO) presents with sudden, painless vision loss and requires immediate stroke center referral within 24 hours, as up to 24% have concurrent cerebrovascular accident on imaging and stroke risk is highest in the first 7 days. 1, 2

Giant cell arteritis (GCA) in patients >50 years with optic disc swelling, absence of emboli, and symptoms of temporal tenderness, jaw claudication, weight loss, or fever represents an ophthalmologic emergency requiring immediate corticosteroid therapy to prevent fellow eye vision loss. 1

Acute angle closure glaucoma presents with painful vision loss, mid-dilated pupil, corneal edema, and elevated intraocular pressure requiring immediate pressure-lowering treatment. 3

Retinal detachment presents with flashes, floaters, and visual field defects requiring urgent ophthalmology consultation for surgical repair. 3, 4

Initial History: Specific Elements to Obtain

Temporal Pattern

• Onset timing: Acute (<24 hours) versus subacute versus chronic 1, 4
• Progression: Sudden versus gradual 4
• Duration: Transient (amaurosis fugax) versus persistent 1

Associated Symptoms

• Pain: Painful (glaucoma, optic neuritis, orbital cellulitis) versus painless (vascular occlusion, retinal detachment) 3, 4
• Neurologic symptoms: Lateralizing weakness, paresthesias, speech changes, or transient ischemic symptoms suggesting stroke 1
• GCA symptoms: Headache, scalp tenderness, jaw claudication, malaise, fever, diplopia, polymyalgia rheumatica history 1
• Visual phenomena: Flashes, floaters (retinal detachment), halos around lights (glaucoma), curtain/shadow (retinal detachment) 3, 4

Cardiovascular Risk Factors

• Hypertension, diabetes, hyperlipidemia, smoking, atrial fibrillation, carotid disease, prior stroke/TIA 1, 5
• Recent trauma or orbital surgery 1

Physical Examination: Essential Components

Visual Acuity Testing

• Test each eye separately with correction if available—establishes baseline function and severity 6, 7

Pupillary Examination

• Check for relative afferent pupillary defect (RAPD) indicating optic nerve or severe retinal pathology 7, 3
• Mid-dilated, poorly reactive pupil suggests acute angle closure glaucoma 3

Intraocular Pressure (IOP)

• Tonometry to detect elevated pressure (>21 mmHg, especially >40 mmHg in acute glaucoma) 6, 7

Visual Field Testing

• Confrontational fields to detect field cuts (retinal detachment, stroke, optic nerve pathology) 7, 4

External Examination

• Conjunctival injection, corneal clarity, anterior chamber depth, lid swelling/erythema 6, 7

Extraocular Movements

• Assess for diplopia, restriction, or pain with movement 1, 7

Fundoscopic Examination

• Critical findings: Optic disc swelling, cherry-red spot (CRAO), retinal whitening, hemorrhages, retinal detachment, papilledema 1, 7, 3
• Direct ophthalmoscopy or point-of-care ocular ultrasound if view obscured 4

Slit Lamp Examination (if available)

• Detailed anterior segment evaluation for corneal pathology, anterior chamber inflammation, lens abnormalities 6, 7

Laboratory Testing: When to Order

Immediate Labs for Suspected GCA (Age >50 with Suggestive Symptoms)

• ESR and CRP: Typically elevated in GCA 1
• Complete blood count with platelets 1
• Do not delay corticosteroid treatment while awaiting results if clinical suspicion is high 1

Hypertensive Emergency Evaluation

• Blood pressure measurement—hypertensive chorioretinopathy can present as blurred vision with BP >200/120 mmHg 8
• Urinalysis, troponin, ECG if hypertensive emergency suspected 8

Glucose

• Rule out hypoglycemia or diabetic complications 4

Imaging Studies

Brain Imaging for Suspected Vascular Events

• MRI with diffusion-weighted imaging (DWI) is preferred over CT for detecting concurrent silent brain infarctions (present in 19-25% of retinal artery occlusions) 1, 2
• CT head without contrast if MRI unavailable or contraindicated 2

Vascular Imaging

• Carotid ultrasound or CTA to assess for carotid stenosis (found in up to 70% of symptomatic CRAO patients) 1, 2

Orbital Imaging (if trauma suspected)

• CT orbits for suspected fracture or foreign body 1
• MRI orbits for soft tissue detail if no metallic foreign body 1

Point-of-Care Ocular Ultrasound

• Rapidly identifies retinal detachment, vitreous hemorrhage, lens dislocation, and increased optic nerve sheath diameter (papilledema) when direct visualization is limited 4

Disposition Algorithm

Immediate Ophthalmology Consultation in ED

• Acute angle closure glaucoma 3
• Retinal detachment 3
• Endophthalmitis 3
• Chemical injury 9
• Globe rupture 3

Immediate Stroke Center/ED Referral (Do Not Delay for Outpatient Workup)

• Retinal artery occlusion within 24 hours of onset for stroke evaluation and potential thrombolysis (if <4.5 hours) 1, 2
• Risk of stroke is 3-6% in first 1-4 weeks 1

Urgent Ophthalmology Referral (Within 24-48 Hours)

• Optic neuritis 3
• Unexplained vision loss requiring dilated examination 4
• Suspected retinal vein occlusion 5

Outpatient Ophthalmology Referral (Within Days to Weeks)

• Chronic, stable vision changes 4
• Refractive error 4

Common Pitfalls to Avoid

Delaying stroke center referral for retinal artery occlusion: Only 35% of ophthalmologists send acute CRAO patients to ED immediately, yet these are stroke equivalents requiring urgent evaluation. 1

Missing GCA in elderly patients: Failure to check ESR/CRP in patients >50 with vision loss and systemic symptoms can result in bilateral blindness. 1

Assuming transient vision loss is benign: Amaurosis fugax carries similar stroke risk to hemispheric TIA and requires urgent vascular workup. 1

Inadequate blood pressure assessment: Hypertensive chorioretinopathy with serous retinal detachment indicates hypertensive emergency with end-organ damage requiring admission. 8

Failing to measure IOP: Acute angle closure can be missed without tonometry, leading to permanent optic nerve damage. 6, 3

Discharging patients with RAPD without explanation: RAPD indicates significant optic nerve or retinal pathology requiring urgent ophthalmology evaluation. 7, 3