Blockage of a vein in the light-sensitive retina at the back of the eye
- Increasingly common over the age of 50
- Gender, genetics, and lifestyle are not significant factors
Retinal vein occlusion (an obstructed vein in the eye’s light-sensitive retina) is usually caused by a blood clot in the vein, preventing blood from draining away from the retina. This may cause the vein to burst, or the rising pressure may cause bleeding in the retina. Blockage of a small vein may not cause symptoms, but, if a large vein is affected, vision may deteriorate in a few hours.
Retinal vein occlusion affects mostly elderly people whose blood vessels are narrowed by atherosclerosis. It is also more common in people with glaucoma, high blood pressure (see Hypertension), or a disorder that makes blood clot easily (see Hypercoagulability).
The blockage of a small vein is often detected during a routine examination of the eye by ophthalmoscopy, but, if your vision deteriorates suddenly, see a doctor at once. In most cases, there is no treatment for the condition itself but treating the underlying cause will stop a recurrence. Small retinal vein occlusions may sometimes be treated by injections of drugs called anti-VEGF agents, which may restore vision in some people. You may also need retinal laser treatment to prevent or treat secondary glaucoma.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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