This literally means a blockage of a major vein of the retina. This can lead to:
- Leakage of blood and fluid into the retina. Vision is reduced if the macula is involved.
- Disrupted blood supply (“Ischaemia”) to the macula
- If Ischaemia is widespread, it can lead to growth of small fragile retinal blood vessels to overcome the lack of oxygen. These can bleed into the eye leading to floaters and reduced vision.
– Blurred or reduced vision
- Raised blood pressure
- Blood Disorders – less common
- Fluorescein Angiogram
A special yellow dye called fluorescein is injected into a vein. It fills the
circulation of the eye and highlights the blockage and the degree of severity of the blockage.
This device takes a “snapshot” of the macula. It gives high resolution images of the macula and is very useful in monitoring improvement after treatment.
- Control risk factors. Your GP will be asked to assess your blood pressure, blood sugar level, cholesterol. Smokers should try to reduce consumption.
In some cases, if the macula is not affected, vision remains good. Observation only is required.
- Intravitreal Injections
Here, medicines are injected into the eye under local anaesthetic.
The 2 main drugs used are Avastin or Triamcinolone. Both drugs have their
pros and cons. Both are effective in reducing blood and fluid at the macula which can improve vision.
Your doctor will discuss appropriate treatment for you.
Often multiple injections are required to achieve optimal vision.
Laser is used to reduce the amount of fluid and blood at the macula.
Studies have shown it to be effective although the onset of effect is slower
than intravitreal injections.
Often laser treatment will be combined with intravitreal injections.
Laser is also used when small fragile retinal blood vessels are present. This causes the blood vessels to shrink away and reduce the risk of bleeding.
Eventually the eye will produce bypass blood vessels to allow flow around the blockage. This can take up to 2 years.
The aim of treatment is to reduce the blood and fluid at the macula ensuring optimal vision while this is occurring.