What is Retinal Vein Occlusion?
RETINAL VEIN OCCLUSION
The retina is a thin neural tissue on the back surface of the eye that is responsible for perceiving light send the light signals to the brain. The retina has arteries that gives it nutrients and vein that carries away blood back to the heart. When retinal veins can be blocked (or occluded) by a clot in the vessels. This causes a backlog of stagnated blood in the retina. This causes a loss of oxygen in the retina as well as spillage of blood and fluid into the substance of the retina, causing varying degrees of vision loss.
The loss of oxygen in the retina can induce new blood vessels to grow on the surface of the retina or on the iris. The abnormal blood vessels can bleed into the eye and cause vision loss, they can also clog up the drainage of fluid out of the eyeball resulting in high eye pressure (neovascular glaucoma).
Factors contributing to retinal vein occlusion include:
· Advancing age.
· High blood pressure, high cholesterol level, diabetes, smoking and obesity.
· High eye pressure.
· Less commonly can be caused by inflammatory eye diseases, Hyperviscosity states such as myeloma and conditions that increases clotting in the blood vessels (thrombophilic disorders).
How is retinal vein occlusion managed?
Vein occlusion is diagnosed by examination of the retina by your eye doctor.
Your eye doctor may confirm the diagnosis with a special test known as fluorescein angiogram which is a photo taken of the retina with contrast given through your vein in your arm.
You will have an OCT scan of the retina to look for the degree of fluid collection (oedema) in the macula area. Reduction of vision caused by oedema of the macula may be treated by your eye doctor with injection of medication in clinic under sterile condition (anti VEGF agent, either Lucentis or Eylea). The medication given will reduce the degree of oedema and preserve your vision.
Your eye doctor will liaise with your GP to help you control the risk factors for retinal vein occlusion to prevent a similar event from happening to your good eye.
Less commonly if new abnormal blood vessels are found in your eye, your doctor may perform laser treatment on the retina to prevent complications caused by these new vessels.