top of page

Central Retinal Vein Occlusion (CRVO)

Definition​

​

  • CRVO refers to blockage of the central retinal vein within or beyond the optic disc

  • This blockage causes increased back pressure through entire venous drainage system of the eye

  • The increased pressure reduces blood flow into the retina, causing hypoxia and retinal damage

​

Causes

​

  • Atherosclerotic changes of the central retinal artery can compress the central retinal vein at points where they cross over, causing compression and occlusion of the vein

  • In other patients, thrombus (clot) formation within the central retinal vein may be the cause

​

Risk factors

​

  • Cardiovascular risk factors - increase the risk of arterial atherosclerosis

  • ​These include:
    • age​
    • hypertension
    • hyperlipidaemia
    • diabetes
    • smoking
  • Other risk factors:
    • oral contraceptive pill​
    • glaucoma
    • myeloproliferative disease e.g. polycythaemia, myeloma
    • thrombophilic conditions: hyperhomocysteinaemia, factor V Leiden, antiphospholipid syndrome
    • chronic kidney disease

​

Presentation 

​

  • Sudden, significant unilateral vision loss

    • this is usually painless​

  • Visual acuity is typically very poor (counting fingers or worse)

​

Examination findings

​

  • 'margherita pizza' appearance on fundal examination

    • more dramatic fundal appearance than BRVO

  • Tortuous and engorged retinal veins 

  • Widespread blot and flame-shaped haemorrhages 360 degrees all the way to periphery

  • Widespread intra-retinal haemorrhage

  • Cotton wool spots

  • Swollen disc

  • Fluid leakage into the retina causing swelling at the macula (the most sensitive part of the retina), known as macular oedema

​

Investigations

​

  • Imaging of fundus, including fundal fluoroscein angiography (FFA) and OCT scan

  • Check blood pressure

  • Blood tests: lipid profile, HbA1c, FBC, U+E, ESR

  • Thrombophilia screen / autoantibody screen in select patients

  • Protein electrophoresis (test for myeloma) in select patients

  • Examination of the drainage angle (gonioscopy) must be performed as CRVO can prompt abnormal vessels to grow in the angle

​

Treatment

​

  • it is important to optimise blood pressure, manage hyperlipidaemia, and blood sugar in diabetics

  • In rarer cases think about clotting screens e.g. younger patient

  • Macular oedema can be treated with intra-vitreal injections: anti-VEGF or steroid

  • Regular review in eye clinic to assess for complications

  • Some patients may develop neovascularisation of the retina as a complication

    • this should be treated with laser - pan-retinal photocoagulation (PRP)​

​

References

  • Salmon, J. F. (2019) Kanski’s clinical ophthalmology. 9th edn. London, England: Elsevier Health Sciences.

bottom of page