Health Information

Diabetes : What is diabetes?

Approximately one person in fifty in the UK is affected by diabetes mellitus or "sugar diabetes". The condition prevents the body from coping normally with sugar and other carbohydrates in a person's diet.

Diabetes can start in childhood, but often begins later in life. It may cause complications which affect different parts of the body.

There are two types of diabetes mellitus - one is controlled by insulin injections, while the other by diet or tablets. Both have the same affect on the eyes.

If you have diabetes this does not necessarily mean your sight will be affected, but there is a higher risk.

If your diabetes is well controlled then you are less likely to have problems or they may be less serious. However, if there are complications which affect the eyes then this can result in loss of sight.

Why regular eye tests are important

Most sight loss from diabetic retinopathy can be prevented, but it is vital that it is diagnosed early.
You may not realise there is anything wrong with your eyesight, and so regular eye checks are extremely important.

How can diabetes affect the eye?

Your eye has a lens and an aperture (opening) at the front, which adjust to bring objects into focus on the retina at the back of the eye. The retina is made up of a delicate tissue that is sensitive to light, rather like the film of a camera.

At the centre of the retina is the macula which is a small area about the size of a pinhead. This is the most specialised part of the retina and it is vital because it enables you to see fine detail and read small print. The other parts of the retina can give you side vision (peripheral vision). Filling the cavity of the eye in front of the retina is a clear jelly-like substance called the vitreous humour.

Diabetes can affect the eye in a number of ways. These usually involve the fine network of blood vessels in the retina - hence the term diabetic retinopathy.

Glaucoma : What is glaucoma?

Glaucoma is the name for a group of eye conditions in which the optic nerve is damaged at the point where it leaves the eye. This nerve carries information from the light sensitive layer in your eye, the retina, to the brain.

Your eye needs a certain amount of pressure to keep the eyeball in shape so that it can work properly. In some people, the damage is caused by raised eye pressure.