What are the appropriate tests for a patient presenting with acute right eye pain and headache in the emergency department?

Appropriate Testing for Acute Right Eye Pain with Headache in the Emergency Department

For patients presenting with acute right eye pain and headache in the emergency department, urgent neuroimaging with MRI brain and orbits with diffusion-weighted imaging, along with laboratory testing for inflammatory markers (ESR/CRP), is essential to rule out vision and life-threatening conditions. 1

Initial Assessment

Critical Symptoms to Evaluate:

• Visual acuity changes
• Character of pain (throbbing, pressure, severity)
• Associated symptoms:
  • Photophobia
  • Nausea/vomiting
  • Redness of the eye
  • Halos around lights
  • Jaw claudication or temporal tenderness (in patients >50)

Essential Physical Examination Elements:

• Visual acuity testing
• Pupil examination (size, shape, reactivity)
• Slit-lamp examination of anterior chamber depth
• Tonometry (intraocular pressure measurement)
• Fundoscopic examination
• Neurological examination

Diagnostic Algorithm

Step 1: Immediate Testing for All Patients

• Visual acuity assessment
• Intraocular pressure measurement
• Slit-lamp examination with fluorescein staining

Step 2: Laboratory Testing

• Complete blood count
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) - especially crucial in patients >50 years to rule out giant cell arteritis 1
• Basic chemistry panel

Step 3: Neuroimaging

• MRI brain and orbits with diffusion-weighted imaging sequences is the preferred imaging modality 1
• If MRI is unavailable or contraindicated (e.g., suspected metallic foreign body), non-contrast CT head and orbits with thin sections should be performed 1

Specific Conditions to Rule Out

1. Acute Angle-Closure Glaucoma

• Presents with severe eye pain, headache, blurred vision, halos around lights
• Immediate tonometry is essential - elevated intraocular pressure >21 mmHg is diagnostic 1
• Treatment may include acetazolamide IV 250-500 mg 2

2. Retinal Artery Occlusion

• Requires urgent evaluation as it may indicate impending stroke
• MRI with DWI is crucial as silent brain infarction is present in 19-25% of cases 1
• Patients should be referred to a stroke center within 24 hours 1

3. Giant Cell Arteritis (in patients >50)

• Presents with headache, eye pain, vision changes, jaw claudication
• Elevated ESR/CRP warrants immediate treatment with corticosteroids 1
• Temporal artery biopsy may be indicated but should not delay treatment

4. Optic Neuritis

• Presents with eye pain worsened by eye movement and vision loss
• MRI brain and orbits with contrast is essential 1

Common Pitfalls to Avoid

1. Failing to measure intraocular pressure - missing acute angle-closure glaucoma can lead to permanent vision loss 1, 3

2. Delaying neuroimaging - retinal artery occlusions require urgent evaluation as they may indicate concurrent stroke (present in up to 24% of cases) 1

3. Not checking inflammatory markers in older patients - giant cell arteritis requires immediate treatment to prevent blindness in the contralateral eye 1

4. Confusing cluster headache with angle-closure glaucoma - both can present with unilateral pain, redness, and autonomic symptoms 4

5. Overlooking "quiet eye" causes of pain - normal-appearing eyes can still harbor serious pathology 5

Special Considerations

• In patients with suspected retinal artery occlusion, evaluation should occur within 24 hours of symptom onset, and patients should be referred to a stroke center 1
• Patients with thunderclap headache require immediate evaluation for subarachnoid hemorrhage 1, 6
• Patients with suspected giant cell arteritis require immediate treatment with corticosteroids before confirmatory testing 1

By following this systematic approach to testing, emergency physicians can efficiently diagnose and appropriately manage potentially vision and life-threatening causes of acute right eye pain with headache.