Retinal Vein Occlusion

What is Retinal Vein Occlusion?

Retinal vein occlusion happens when a vein in the retinal circulation becomes blocked. The retinal veins are blood vessels inside the eye which drain blood away from the retina back to the heart. When it cannot drain properly, there is pooling of blood which in turn may cause the area to swell and bleed (haemorrhage). Macular edema (or swelling of the macula) is a common cause of visual impairment in retinal vein occlusion. Sometimes serious complications of retinal vein occlusion may occur including vitreous hemorrhage or rubeotic glaucoma which may result in blindness or even loss of the eye if the condition is not treated properly.

There are two forms of retinal vein occlusion:

  • Central Retinal Vein Occlusion (CRVO): This occurs when the large central retinal vein at the optic nerve is blocked resulting in poor blood flow throughout the entire retina and can cause severe visual loss.
Retinal Vein Occlusion - Central

Retinal Vein Occlusion – Central

  • Branch Retinal Vein Occlusion (BRVO): This occurs when a branch of retinal vein is blocked. Visual loss may not as be severe as CRVO.
Retinal Vein Occlusion

Retinal Vein Occlusion – Branch

Who is at risk?

Because the main cause of Retinal Vein Occlusion is atherosclerosis (hardening or thinning of arteries and veins), it is seen more common in people with:

  • High blood pressure
  • High cholesterol
  • Diabetes
  • Glaucoma
  • Blood disorders
  • History of smoking

What are the symptoms?

  • Blurred vision, due to leakage of fluid into the macula
  • Floaters, seen as spots which float in your visual field
  • Pain in the eye, due to excessive eye pressure
  • Sudden/gradual visual loss

How is it diagnosed?

Retinal Photography and an OCT Scans are taken to assess the leakage (macular edema). Our retina specialists may also perform Fluorescein Angiography to assess the severity of the retinal vein occlusion and to guide treatment. In addition, other blood tests or tests involving other parts of the body may also be ordered to determine underlying possible causes.

How can it be treated?

Our retina specialists will discuss the different treatment options with you. The options include intravitreal injections such as Bevacizumab or Triamcinolone into the eye, Multispot Micropulse Yellow Laser Surgery, conventional thermal laser surgery, vitreoretinal surgery, lowering blood pressure and diet and lifestyle modifications.

From October 1, 2015, a new treatment for Retinal Vein Occlusion will be available on the PBS (Pharmaceutical Benefits Scheme). Aflibercept is a type of injection in the eye to treat swelling of the macula part of the retina (CRVO) which can cause blindness or vision loss if left untreated. This joins another new eye injection Ranibizumab for both BRVO and CRVO which has recently been available on the PBS since July 1 2015.