Retinal Vein Occlusions
When blood vessels to the retina are blocked it is known as a retinal vein occlusion or ‘eye stroke’, and can cause sudden blindness.
The retina is the part of the eye where light is focused and converted to electrical signals that are sent to the brain. A retinal vein occlusion is a blockage of the blood vessels that feed the retina, and can result in sudden and serious vision problems.
Retinal vein occlusion symptoms
Just as a stroke can occur suddenly and without warning, symptoms of a retinal vein occlusion or ‘eye stroke’ usually occur quite suddenly. A sudden loss of vision, or sudden blurring of vision, is often the first sign that many people are aware of. The severity of symptoms differs from person to person, and also depends on whether the blockage is to the central or a branch vein.
Brach retinal vein occlusion (BRVO)
A branch retinal vein occlusion (BRVO) refers to a blockage of the smaller retinal veins. This usually results in blurred vision, or a missing area of vision. Many people with a BRVO find that their vision gradually improves again over time, as the eye naturally heals itself.
Central retinal vein occlusion (CRVO)
A blockage to the central or main retinal vein is more serious, and usually involves a more severe loss of vision. Total loss of central vision is not unusual, and recovery is less likely than with a BRVO.
In most cases of retinal vein occlusions, vision problems are caused by fluid leaking from blocked blood vessels into the vitreous ‘gel’ inside the eye. However, a secondary problem is the growth of new and abnormal blood vessels. These grow into the vitreous cavity, rather than into the damaged retina, and can often bleed, blocking off vision. This is known as a vitreous haemorrhage.
CRVO in particular can also lead to glaucoma in some people.
Causes of retinal vein occlusions
Just like a stroke causes damage to other parts of the body when blood circulation fails, a retinal vein occlusion causes damage to the eye. When the blood flow to the retina is blocked, oxygen and nutrients cannot reach it, and a haemorrhage occurs.
A retinal vein occlusion usually occurs because of a hardening of the arteries, which causes a clot. People with certain medical conditions, like diabetes and high blood pressure, are more at risk of a retinal vein occlusion than others. Retinal vein occlusions are also most common in people over 60 years of age.
Retinal vein occlusion treatment
Treatment for retinal vein occlusions depends on their type and severity, and can include laser treatment, drug injections or a vitrectomy. A BRVO may not require any treatment, and may heal itself given time. A CRVO, on the other hand, may require immediate treatment.
If you suffer any of the symptoms of a retinal vein occlusion, it’s important to see an eye specialist straight away. You can make an appointment with an experienced eye doctor at Eye Institute for a full diagnosis and treatment.
If you are diagnosed with a retinal vein occlusion, you should also visit your GP for a check-up, as you may be more at risk of clotting and circulation problems in other parts of your body.