HealthInfo Waitaha Canterbury

Diabetic retinopathy

Diabetic retinopathy is a complication of diabetes, caused by high blood sugar levels damaging the back of the eye (retina). It can cause blindness if left undiagnosed and untreated.

The tiny blood vessels that bring blood to the retina become damaged in three main stages.

• Background retinopathy – tiny bulges develop in the blood vessels, which may bleed slightly but do not usually affect your vision.
• Pre-proliferative retinopathy – more severe and widespread changes affect the blood vessels, including more significant bleeding into the eye.
• Proliferative retinopathy – scar tissue and new blood vessels, which are weak and bleed easily, develop on the retina. This can result in some loss of vision.

You're more at risk if:

• You've had diabetes for many years. The risk increases progressively each year from the time of diagnosis. After 15 years, three out of four people will have retinopathy.
• Your diabetes is not well controlled.
• You also have high blood pressure (hypertension), high cholesterol or kidney disease.

Symptoms of diabetic retinopathy

In the early stages you'll have no symptoms.

You may develop several eye problems such as:

• gradually worsening vision
• sudden vision loss
• shapes floating in your field of vision (floaters)
• blurred or patchy vision
• eye pain or redness
• difficulty seeing in the dark.

See your general practice team or optometrist if you get any of these symptoms.

Diagnosing diabetic retinopathy

Diabetic retinopathy is diagnosed by looking at the back of your eye either directly or from photos. These are done as part of a diabetic eye check (retinal screening).

Treating diabetic retinopathy

Treatment doesn't cure diabetic retinopathy and it doesn't usually restore your vision to what it was before. But it can slow down the damage and stop new damage from happening. It's very important that you get good control over your blood glucose (sugar), as this can reduce any further damage.

Laser treatment

If diabetic retinopathy is threatening your vision, laser treatment may be an option.

The laser seals leaking blood vessels in your retina. It also stops fragile, abnormal blood vessels from growing. These blood vessels may bleed and suddenly reduce your sight.

Focal laser treatment is when the laser can just treat one spot, such as the macula.

Panretinal photocoagulation (pan-re-tin-al foto-co-ag-u-lay-shun) is laser treatment used more widely in the retina. This helps to slow down or stop any further damage.

Injections

Medicines such as Avastin (bevacizumab), Lucentis (ranibizumab) and Eylea (aflibercept) can help. They reduce the growth of abnormal blood vessels and the amount of fluid leaking from them.

These medicines can be injected into your eye after it's numbed with a local anaesthetic. This treatment is especially useful if the retinopathy is affecting your macula. Your macula is the part of the retina that is responsible for fine, detailed vision.

You may just need one injection, or you may need several injections.

Surgery

If you have advanced diabetic eye disease and severe loss of vision, you may need retinal surgery. If you have this surgery, you may need to stay in hospital overnight.

Preventing diabetic retinopathy

You can reduce your risk of diabetic retinopathy by:

• keeping your diabetes as well controlled as possible
• having regular diabetic eye checks
• having treatment for high blood pressure (hypertension) and high cholesterol, which cause additional harm to your eyes if not controlled
• following medical advice about what you eat, physical activity, medications for diabetes, blood pressure and high cholesterol
• not smoking. Smoking can cause strokes, heart attacks and poor circulation in the legs which may result in amputation. See quitting smoking.

  HealthInfo recommends the following pages

• American Association of Ophthalmology – Diabetic retinopathy treatment

  More information about treatments for diabetic retinopathy, including short, animated videos.

Written by HealthInfo clinical advisers. Last reviewed March 2023.

Sources

Page reference: 139221

Review key: HIDYE-139181