Central Retinal Artery Occlusion, Emergency Medicine

Basics

Description

- Embolic: - Occlusion by intravascular material from a proximal source: - Atherosclerotic disease (majority) - Carotid artery stenosis - Valvular heart disease (cardiogenic emboli) - Atrial myxoma - Dissection of the ophthalmic artery - Carotid artery dissection

- Thrombotic: - Obstruction of flow from the rupture of a pre-existing intravascular atherosclerotic plaque - Hypercoagulable states (sickle cell)

- 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"пїЅ 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"пїЅ) - Within 1-2 hr opacification of the usually transparent infarcting retinal nerve layer occurs.

Obstruction of the central retinal artery associated with sudden painless loss of vision
Usually occurs in persons 50-70 yr of age
Ophthalmic artery is 1st branch of carotid.
Risk factors include HTN, atherosclerotic disease, sickle cell disease, vasculitis, valvular heart disease, lupus, trauma, and coronary artery disease.
Incidence of 1-10/100,000
Often described as a "stroke of the eye"пїЅ

Etiology

Embolic:Occlusion by intravascular material from a proximal source:Atherosclerotic disease (majority)Carotid artery stenosisValvular heart disease (cardiogenic emboli)Atrial myxomaDissection of the ophthalmic arteryCarotid artery dissection
Thrombotic:Obstruction of flow from the rupture of a pre-existing intravascular atherosclerotic plaqueHypercoagulable states (sickle cell)
Inflammatory:Due to temporal arteritis, lupus, vasculitis
Arterial spasm:Associated with migraine headaches
Decreased perfusion:Low-flow conditions such as in severe hypotension or high-pressure situations seen in acute angle-closure glaucoma or retrobulbar hemorrhage

Diagnosis

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 retinaAppears as glinting white or yellow flecks (Hollenhorst plaques) within the vesselsIschemic edema visible within 15-20 min of occlusion"Cherry-red spot"пїЅ 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"пїЅ)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: пїЅ

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: пїЅ

Carotid artery ultrasound/Doppler
Possibly echocardiography
Fluorescein angiography or electroretinography to confirm the diagnosis

Differential Diagnosis

Acute angle-closure glaucoma
Central retinal vein occlusion
Giant cell arteritis (temporal arteritis)
Optic neuritis
Retinal detachment

Treatment

Initiate treatment immediately because irreversible visual loss occurs at 90 min: пїЅ

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 onsetMay 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 pressurePossible 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

Methylprednisolone: 250 mg IV in suspected cases of inflammatory arteritis
Aspirin: 325 mg PO
Mannitol
Sublingual nitroglycerin

Follow-Up

Disposition

Admission Criteria

Required for workup of proximal cause in acute cases (source of embolism, thrombosis, or inflammatory) пїЅ

Discharge Criteria

Chronic retinal artery occlusion with no evidence of active disease can be worked up as an outpatient. пїЅ

Issues for Referral

All suspected cases warrant emergent ophthalmology consultation. пїЅ

Followup Recommendations

Most cases will require carotid ultrasound to exclude atherosclerotic disease. пїЅ

Pearls and Pitfalls

Amaurosis fugax (transient, possibly resolved retinal artery occlusion) is a sentinel event and may lead to complete occlusion or stroke. Do not ignore these symptoms and urgent workup is required.
Retinal artery occlusion is a medical emergency requiring immediate treatment to prevent loss of the eye.
It is important to document a full eye exam including visual acuity and evaluation of the optic fundus.

Additional Reading

Arnold пїЅM, Koerner пїЅU, Remonda пїЅL, 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 пїЅSG, Adams пїЅW. Interventions for acute non-arteritic central retinal artery occlusion. Cochrane Database Syst Rev. 2009;(1):CD001989.
Hazin пїЅR, Daoud пїЅYJ, Khan пїЅF. Ocular ischemic syndrome: Recent trends in medical management. Curr Opin Ophthalmol. 2009;20:430-433.
Murphy-Lavoie пїЅH, Butler пїЅF, Hagan пїЅC. Central retinal artery occlusion treated with oxygen: a literature review and treatment algorithm. Undersea Hyperb Med. 2012;39(5):943-953.
Vortmann пїЅM, Schneider пїЅJL. Acute monocular visual loss. Emerg Med Clin North Am. 2008;26(1):73-96.

Codes

ICD9

362.31 Central retinal artery occlusion пїЅ

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
H34.13 Central retinal artery occlusion, bilateral
H34.1 Central retinal artery occlusion

SNOMED

38742007 Central retinal artery occlusion