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Diabetic retinopathy affects 1.8 million people globally. It is caused by damage to the small blood vessels in the retina at the back of the eye as a result of diabetes.

What is diabetes?

Diabetes is characterised by a lack of insulin, or the inability to use insulin effectively. This results in hyperglycaemia, an excess of glucose in the bloodstream. There are over 171 million people with diabetes worldwide, but this is likely to double by 2030 to 366 million. Up to 50% do not know they have the condition.

The most common kind of diabetes is called type two, accounting for over 90% of cases today. It is often caused by poor diet, obesity, a lack of exercise, or a genetic predisposition.

How diabetes affects the eye

Diabetes can affect retinal blood vessels in two ways: they can become leaky, or they can become blocked. Both lead to retinopathy: a gradual or painless a loss of vision in one or both eyes. If peripheral blood vessels become blocked this can stimulate the growth of new, abnormal ones ("proliferative retinopathy") which in turn can bleed, or lead to detachment of the retina.

As a general rule, the risk of retinopathy increases the longer the person has had diabetes, although sight loss can take many years. However, not all diabetics will develop retinopathy.

Sightsavers’ solution

Sightsavers supports the training of health workers to diagnose and treat diabetic retinopathy. However it can be a difficult disease to prevent as people may not realise they have diabetes: the first symptom could be retinopathy - the gradual or sudden painless loss of vision in one or both eyes.

The treatment for diabetic retinopathy is laser surgery, to reduce leaking from the retinal blood vessels. This treatment is more effective at preserving sight if the retinopathy is detected and treated early. In severe proliferative retinopathy, (when abnormal blood vessels have formed) some people need an operation called a vitrectomy to restore vision.

Prevention

• Health workers can help reduce the risk of retinopathy for people who already have diabetes by advising people to do the following:
• Have good control of blood sugar (using the treatment they have been prescribed, in combination with a low carbohydrate diet).
• Have good control of blood pressure.
• Reduce factors that are known to damage blood vessels, such as smoking.
• Have regular eye examinations even if their vision is normal.

Successful treatment

65-year-old Indra Arora from Nehru Nagar in Delhi, India, came to an eye screening camp with blurred vision. She was diagnosed as having diabetic retinopathy and referred to the hospital at the Venu Eye Institute, where she has had three sittings of laser treatment. Had she not had this treatment she was risking a haemorrhage in the eye which would have then needed major surgery to save it.