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.
Branch 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.
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.
This condition usually occurs because of a hardening of the arteries, which then press on the vein.. 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.
Treatment depends on 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.
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.