EM@3AM – Central Retinal Vein Occlusion

Author: Olivier Levac-Martinho, MD, BSc (@OlMartinho, Resident Physician, University of Ottawa) and Erica Simon, DO, MHA (@E_M_Simon, EMS Fellow, SAUSHEC, USAF) // Edited by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW / Parkland Memorial Hospital) and Brit Long, MD (@long_brit, EM Attending Physician, SAUSHEC, USAF)

Welcome to EM@3AM, an emdocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 52-year-old male, with a previous medical history of CAD (CABG x3), HTN, DM, and smoking (30 pack years), presents to the emergency department following the painless loss of vision in his left eye. The patient denies headache, slurred speech, and motor and sensory deficits. He denies contact lens wear and denies a requirement for glasses. The man reports an eye examination within the previous year, stating “my eyes have been perfect.”

Initial VS: BP 123/76, HR 66, T 99.9F Oral, RR 12, SpO2 97% on room air.

Visual Acuity:
OD: 20/20
OS: 20/400
OU: 20/200

Pertinent physical exam findings:
HEENT: PERRLA, 2mm bilaterally, EOMI. OS: Tonometry: IOP 18 mmHg. Fundoscopy: retinal hemorrhages, cotton-wool spots, optic disc edema.
Cardiovascular: S1, S2, regular rate and rhythm. No carotid bruits.

What’s the next step in your evaluation and treatment?

 Answer: Central Retinal Vein Occlusion (CRVO)1-4

  • Epidemiology: CRVO typically occurs in persons > 65 years of age with a history of atherosclerotic disease. Risk factors include DM, HTN, vasculitis (systemic lupus erythematosus, HIV, syphilis, sarcoidosis, etc.), glaucoma (increased IOP = bowing of the lamina with subsequent impingement of the central retinal vein), and hypercoagulable states (hyperviscosity syndromes, protein C deficiency, protein S deficiency, etc.).1,2 Population studies report the prevalence of CRVO as 0.1-0.4% (incidence highest among African American individuals).1,2
  • Etiology: Occurs secondary to a thrombus occluding the lumen of the central retinal vein, compression of the central retinal vein by an atherosclerotic central retinal artery, or occlusion of the central retinal vein secondary to inflammation.1,3
  • Clinical Manifestations: Sudden onset, or progressively worsening, painless, monocular vision loss.1,4
  • Evaluation and Treatment:
    • Obtain visual acuity (vision often significantly reduced in the affected eye (> 20/200)).2,3
    • Perform a thorough H&P:
      • Question specifically regarding the aforementioned risk factors. Obtain a complete family history to include systemic thrombotic diseases and rheumatologic diseases.
    •  Ocular examination: pupillary exam may demonstrate an ipsilateral afferent pupillary deficit.2
      • Fundoscopic retinal exam: retinal hemorrhages in all quadrants of the fundus (“blood and thunder” appearance), optic nerve head swelling, splinter hemorrhages, cotton-wool spots, and macular edema +/- breakthrough vitreous hemorrhage.1,2
    • Consider a more extensive evaluation in persons < 65 years of age presenting without known risk factors for CRVO (e.g. blood dyscrasias: CBC, coags, etc.).
    •  Treatment => Emergent ophthalmology consult.
      • Available therapies include aspirin, anticoagulation, photocoagulation, and intravitreal injections (anti-vascular endothelial growth factors, steroids, etc.)1
      • Treatment of, or referral for, the management of CRVO systemic vascular risk factors (e.g. HTN, DM, etc.) is advised.
  • Pearls:
    • Nearly 7% of persons presenting with unilateral CRVO develop the condition in the contralateral eye within 5 years of onset of the first eye.1
    • The differential diagnosis of CRVO includes: stroke, TIA, amaurosis fugax, temporal arteritis, retinal detachment, and posterior vitreous detachment.1



  1. Oellers P, Hahn P, Fekrat S. Central Retinal Vein Occlusion. In Ryan’s Retina. 6th ed. 2018. Philadelphia, Elsevier. 57; 1166-1179.
  2. Cugati S, Ten-year incidence of retinal vein occlusion in an older population: the Blue Mountains Eye Study, Arch Ophthalmol. 2006 May; 124(5):726-32.
  3. Klein R, The epidemiology of retinal vein occlusion: the Beaver Dam Eye Study; Trans Am Ophthalmol Soc. 2000;98:133-41
  4. Green WR, Central retinal vein occlusion: a prospective histopathologic study of 29 eyes in 28 cases, Trans Am Ophthalmol Soc. 1981; 79:371-422.


For Additional Reading:

Acute Visual Loss in the Emergency Department: Pearls and Pitfalls

Acute Visual Loss in the Emergency Department: Pearls and Pitfalls

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