Diabetic retinopathy is a common complication of diabetes. It occurs when high blood sugar levels damage the cells at the back of the eye (known as the retina). If it isn't treated, it can cause blindness.

It's important for people with diabetes to control their blood sugar levels. Everyone with diabetes who is 12 years old or over should have their eyes examined once a year for signs of damage (see below).

All people with diabetes are at risk of getting diabetic retinopathy, but good control of blood sugar levels, cholesterol and blood pressure minimises this risk.

How diabetes can damage the retina

The retina is the light-sensitive layer of cells at the back of the eye. It converts light into electrical signals.

The signals are sent to the brain through the optic nerve and the brain interprets them to produce the images that you see.

To work effectively, the retina needs a constant supply of blood, which it receives through a network of tiny blood vessels.

Over time, a continuously high blood sugar level can cause the blood vessels to narrow, bleed or leak. This damages the retina and stops it from working.

When the blood vessels in the central area of the retina (the macula) are affected, it's known as diabetic maculopathy.

Read more about the causes of diabetic retinopathy.

Symptoms of diabetic retinopathy

During the initial stages, retinopathy does not cause any noticeable symptoms. You may not realise that your retina is damaged until the later stages, when your vision becomes affected. Vision loss will probably be permanent at this late stage, which is why diabetic eye screening is so important.

If you have diabetes and start to notice problems with your vision, contact your GP or diabetes care team immediately.

Read more about the symptoms of diabetic retinopathy.

Screening for diabetic retinopathy

As severe retinopathy can cause sudden blindness, it needs to be identified and treated as soon as possible.

The NHS Diabetic Eye Screening Programme aims to reduce the risk of vision loss in people with diabetes. This is done by identifying retinopathy at an early stage and ensuring that treatment is given to reduce or prevent sight damage.

Everyone with diabetes who is 12 years old or over is invited for screening once a year. 

The screening test involves examining the back of the eyes and taking photographs of the retina. Screening can detect diabetic retinopathy before you notice any changes to your vision.

Read more about diabetic eye screening.

Treating diabetic retinopathy

Treatment for retinopathy will depend on the stage the condition has reached.

For example, if retinopathy is identified in its early stages, you can prevent it from getting worse just by controlling your diabetes.

If you have more advanced retinopathy, you may need to have laser surgery or injection therapy to prevent further damage to your eyes.

Read more about treating diabetic retinopathy.

Preventing diabetic retinopathy

To reduce your risk of developing retinopathy, it's important to control your blood sugar level, blood pressure and cholesterol level. Good control will prevent diabetic complications in almost everyone.

Read more about preventing diabetic retinopathy.

Other steps that you can take to help prevent retinopathy include:

• attending your annual screening appointment
• informing your GP if you notice any changes to your vision (do not wait until your next screening appointment)
• taking your medication as prescribed
• losing weight (if you're overweight) and eating a healthy, balanced diet
• exercising regularly 
• giving up smoking
• controlling your blood pressure and cholesterol levels