Diabetes and your eyes

People with diabetes can have eye problems due to leaky or blocked blood vessels in the retina, the layer at the back of the eye, over time this can cause sight loss.

Diabetes is a common condition where there is too much sugar in the blood. It can be treated, but even with treatment, people with diabetes have a higher risk of developing eye problems.

When you eat certain foods, your body turns the foods into glucose (sugar), insulin then helps your body store the glucose allowing it to be released gradually maintaining a steady level of glucose in the blood. Diabetes is a condition where there is too much sugar in the blood. This happens because the pancreas doesn’t produce enough insulin, or the insulin doesn’t have the effect it should.

The longer you have diabetes, the more likely you are to develop eye problems. If your diabetes is poorly controlled this also increases the chance that you will develop diabetic eye disease, also known as diabetic retinopathy.

If you have diabetes you may not notice the signs or symptoms of early diabetic eye problems. You should get your eyes checked regularly to pick up any changes. In almost all UK areas, a screening programme will invite you to get an annual eye check using digital photography for diabetic eye disease if you have diabetes. It is extremely important to have this done. Laser treatment of the problem blood vessels can prevent further sight loss for nine people in 10, but improvement in sight which has already been lost is only possible for a minority.

People with diabetes are twice as likely to develop glaucoma as other adults and also tend to develop cataract at an earlier age.

Diabetic eye disease develops gradually over time – the longer you have diabetes the more likely you are to have eye problems. Nearly everyone with Type 1 diabetes will have diabetic eye disease 20 years after their initial diagnosis. Around six people in 10 with Type 2 diabetes show signs of eye disease 20 years after diagnosis.

There are a number of factors that will raise your risk of diabetic eye disease. You have a higher risk of diabetic eye disease if you are diabetic and:

• You have had diabetes for a long time. It is uncommon in people who have had diabetes for less than five years, but almost everyone who has had diabetes for over 30 years has signs of eye disease
• Your diabetes is not well controlled, but some people who control their condition well will still develop diabetic eye disease
• You have high blood pressure that is not well controlled
• You have diabetic kidney disease (known as nephropathy)
• You are pregnant, particularly if your diabetes is poorly controlled
• You smoke
• You are obese
• You have high cholesterol

If you know you have diabetes and are aged 12 or over you should be invited to a special eye test at least every year, how often you are offered an appointment will depend on your own particular circumstances. Some people attend for a diabetic eye check at a high street optical practice, while others may be seen in a hospital clinic or community screening centre.

When you go for a screening appointment your eye specialist will:

• Check your level of vision
• Check the pressure inside the eye, this will be done either using a small probe that rests on the eye or a machine that sends out a puff of air – checking the pressure helps the practitioner look for developing glaucoma
• Give you some eye drops which will dilate your pupil allowing the eye specialist to get a really good view of the back of the eye; your eye care professional will then shine a bright light into the eye to check the tiny blood vessels on the retina – this may be dazzling but isn’t painful
• Take a photograph of the back of the eye – this gives your specialist the ability to more easily compare changes at the back of the eye year on year

After the tests your eyesight will be blurred until the drops wear off, you will have to arrange an alternative way home as you won’t be able to drive.

Read more about the national programme for diabetic eye checks at http://diabeticeye.screening.nhs.uk/.

If you have diabetes there are a number of things you can do to minimise sight problems:

• Attend a regular eye check every year, or more often if advised by your specialist
• Take care to control your blood sugar as well as possible; this can delay the start of eye problems, slow their progression and reduce the need for laser surgery – talk to your GP about controlling your diabetes
• For adults, looking after your blood pressure and cholesterol can also reduce the risk of sight loss – again, get medical advice to help with this
• Do not smoke as this can add to problems – if you smoke speak to your GP or pharmacist about getting help to stop
• Exercise regularly and aim to lose any extra weight; if you have problems losing weight ask your GP for referral to a dietitian; if you need help getting fit ask about exercise programmes in your local health centre
• If you notice an increase in spots floating in your vision or your vision becomes blurred, contact your specialist as soon as possible