Central retinal artery occlusion

Background

Eye anatomy.

• Abbreviation: CRAO
• The first branch of internal carotid artery is the ophthalmic artery
• More common in the elderly with carotid artery disease
• Restoration of blood flow within 100min may lead to complete recovery
  • Occlusion >240min leads to irreversible damage
• 5-10% of CRAO is associated with giant cell arteritis

Etiology

• Embolism
• Thrombosis
• Temporal Arteritis
• Vasculitis
• Sickle Cell Disease
• Trauma
• Vasospasm (migraine)
• Glaucoma
• Low retinal blood flow (carotid stenosis or hypotension)

Clinical Features

• Sudden, painless, monocular vision loss
  • Often preceded by episodes of amaurosis fugax
• APD

Fundoscopy

Typical central retinal artery occlusion with cherry-red spot, retinal edema and narrowing of the vessels.

• Pale retina, cherry red macula
• Boxcar segmentation of blood column
• Cherry red spot
  • Macula is thinnest portion of retina
  • Intact underlying choroidal circulation remains visible through this section
    • Macular area maintains normal color (red) versus surrounding ischemic, pale retina due to differing blood supplies

Differential Diagnosis

Acute Vision Loss (Noninflamed)

• Painful
  • Arteritic anterior ischemic optic neuropathy
  • Optic neuritis
  • Temporal arteritis^†
• Painless
  • Amaurosis fugax
  • Central retinal artery occlusion (CRAO)^†
  • Central retinal vein occlusion (CRVO)^†
  • High altitude retinopathy
  • Open-angle glaucoma
  • Posterior reversible encephalopathy syndrome (PRES)
  • Retinal detachment^†
  • Stroke^†
  • Vitreous hemorrhage
  • Traumatic optic neuropathy (although may have pain from the trauma)

^†Emergent Diagnosis

Evaluation

• Etiology work-up
  • ESR and CRP
  • Carotid US
  • ECG
  • Echocardiography for embolus or atrial shunt
  • CBC, coags, ANA, syphilis

Management

• Consult ophtho with goals for reducing intraocular pressure, dislodging the embolus or increasing arterial flow

• Start high dose systemic corticosteroids if high ESR/CRP (especially high CRP) and sudden vision loss
  • Median starting PO prednisone 80mg/day, with 40% of patients on > 100mg/day
  • Treat until BOTH ESR and CRP stabilize (~2-3 wks)

No evidence supporting or refuting the following treatments:

• Ocular massage
  • Intermittent direct digital pressure applied through closed eyelid x 10-15 sec with rapid release to create pressure gradient to dislodge embolism
• Timolol ophthalmic 0.5% to decrease intraocular pressure
  • Alternative acetazolamide 500mg IV or PO
• Increase PCO2 leading to retinal artery vasodilation/increased retinal blood flow
  • Rebreathe into paper bag x10 min q hr
  • Inhale 95% O2 and 5% CO2 (Carbogen)
• Anterior chamber paracentesis
  • Causes acute drop in IOP to dislodge embolism
• Intraarterial fibrinolysis or low dose systemic thrombolytics
• Acetazolamide, 500mg IV or PO
• Mannitol

Disposition

• Immediate ophthalmology consult

See Also

• Acute vision loss (noninflamed)