SIGNS AND SYMPTOMS 
History
- Sudden, painless, monocular loss of vision
- Prior episodes of sudden visual loss:
- May last a few seconds to minutes (amaurosis fugax)
- Caused by transient embolic phenomena or decreased ocular blood flow
Physical Exam
- Significantly decreased visual acuity
- Afferent pupillary defect usually present
- Retinal appearance:
- Emboli visualized within vascular tree of the retina
- Appears as glinting white or yellow flecks (Hollenhorst plaques) within the vessels
- Ischemic edema visible within 15–20 min of occlusion
- "Cherry-red spot" remains over the fovea (only area where there is very thin retina allowing the vascular choroids to show through).
- Affected arteries empty or showing dark red stationary or barely pulsatile segmented rouleaux ("box-carring")
- Within 1–2 hr opacification of the usually transparent infarcting retinal nerve layer occurs.
- Partial field deficits:
- Occur only if branch of central retinal artery involved
ESSENTIAL WORKUP
- Visual acuity and visual field testing
- Fundoscopic exam
- Intraocular pressure measurements
- Emergent ophthalmologic consultation
DIAGNOSIS TESTS & INTERPRETATION
Lab
Directed toward evaluating underlying etiology of occlusion:
- CBC with differential and platelet count
- PT/PTT
- Electrolytes, BUN/creatinine, glucose
- Electronic spin resonance for giant cell arteritis (in patients > 55 yr old)
- ANA, RF, CRP, ESR
- Rapid plasma reagin (RPR)
- Hemoglobin electrophoresis
- Serum protein electrophoresis
Imaging
Directed toward evaluating underlying etiology of occlusion:
- Carotid artery ultrasound/Doppler
- Possibly echocardiography
- Fluorescein angiography or electroretinography to confirm the diagnosis
DIFFERENTIAL DIAGNOSIS
[Outline]
ALERT
Initiate treatment immediately because irreversible visual loss occurs at 90 min:
- Only immediate treatment may help to salvage or restore sight to the affected eye.
- Goals of therapy include dislodging or dissolving the embolus, arterial dilation to improve forward flow, and reduction of intraocular pressure to improve the perfusion gradient.
ED TREATMENT/PROCEDURES
- Immediate global massage in an attempt to dislodge the embolus:
- Lay patient flat and apply digital global massage bolus.
- On closed eyelid, apply constant pressure for 15 sec and remove for 15 sec. Repeat for 5 cycles.
- Initiate high-flow oxygen via 100% nonrebreather:
- Consider transfer to a facility capable of providing hyperbaric oxygen (HBO) if < 24 hr from symptom onset
- May use inhaled carbogen (a mixture of carbon dioxide and oxygen gas) if available
- Administer IV acetazolamide to decrease intraocular pressure.
- Apply topical timolol maleate to reduce intraocular pressure.
- Administer aspirin and IV heparin for prevention of clot propagation.
- Obtain emergent ophthalmology consultation for:
- Anterior chamber paracentesis to help reduce intraocular pressure
- Possible intra-arterial fibrinolysis for clot lysis
- Administer high-dose systemic steroids in suspected cases of inflammatory arteritis.
MEDICATION
First Line
- Acetazolamide: 500 mg IV or PO
- Carbogen: Inhalation of 95% oxygen and 5% carbon dioxide mixture
- Heparin: 80 U/kg IV bolus then 18 U/kg/h continuous infusions (rate adjusted based on PTT level)
- Timolol maleate 0.5% solution: 1 drop topically to affected eye
Second Line
[Outline]
DISPOSITION
Admission Criteria
Required for workup of proximal cause in acute cases (source of embolism, thrombosis, or inflammatory)
Discharge Criteria
Chronic retinal artery occlusion with no evidence of active disease can be worked up as an outpatient.
Issues for Referral
All suspected cases warrant emergent ophthalmology consultation.
FOLLOW-UP RECOMMENDATIONS
Most cases will require carotid ultrasound to exclude atherosclerotic disease.
[Outline]
ICD9
362.31 Central retinal artery occlusion
ICD10
- H34.10 Central retinal artery occlusion, unspecified eye
- H34.11 Central retinal artery occlusion, right eye
- H34.12 Central retinal artery occlusion, left eye
[Outline]
- Arnold M, Koerner U, Remonda L, et al. Comparison of intra-arterial thrombolysis with conventional treatment in patients with acute central retinal artery occlusion. J Neurol Neurosurg Psychiatry. 2005;76(2):196–199.
- Fraser SG, Adams W. Interventions for acute non-arteritic central retinal artery occlusion. Cochrane Database Syst Rev. 2009;(1):CD001989.
- Hazin R, Daoud YJ, Khan F. Ocular ischemic syndrome: Recent trends in medical management. Curr Opin Ophthalmol. 2009;20:430–433.
- Murphy-Lavoie H, Butler F, Hagan C. Central retinal artery occlusion treated with oxygen: a literature review and treatment algorithm. Undersea Hyperb Med. 2012;39(5):943–953.
- Vortmann M, Schneider JL. Acute monocular visual loss. Emerg Med Clin North Am. 2008;26(1):73–96.
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