Diabetic retinopathy

Over time, too much glucose in your blood can cause the blood vessels in your retina to swell and leak. It can also cause them to close, which stops blood from passing through. Sometimes, abnormal new blood vessels grow on the retina.

The damage this causes to your eye happens in 3 main stages.

1. Background retinopathy — tiny bulges develop in the blood vessels, which may bleed slightly but do not usually affect your vision.
2. Pre-proliferative retinopathy — more severe and widespread changes affect the blood vessels, including more significant bleeding into the eye.
3. 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.

Diabetic retinopathy usually gets worse gradually, over several years. Treatment can help stop it from progressing to the next stage.

You are more at risk if:

• you have had diabetes for many years — the risk increases progressively each year from the time you were diagnosed and after 15 years, 3 out of 4 people will have retinopathy
• your diabetes is not well controlled
• you also have high blood pressure (hypertension), high cholesterol or kidney disease.

In the early stages of retinopathy, you will have no symptoms.

Over time, 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 healthcare provider or optometrist if you get any of these symptoms.

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).

Diabetic eye check

Diabetic retinopathy involves the growth of new abnormal blood vessels in the retina. This can lead to serious vision problems. 

• Vitreous haemorrhage — the new blood vessels may bleed into the clear, jelly-like substance that fills the centre of your eye. This can lead to dark spots (floaters) in your vision or in more severe cases, it can completely block your vision. The blood clears from your eye over time and usually does not cause permanent vision loss.
• Retinal detachment — the new blood vessels stimulate the growth of scar tissue, which can pull the retina away from the back of the eye. This can cause spots floating in your vision, flashes of light or severe vision loss.
• Glaucoma — new blood vessels can grow in the front part of your eye (iris) and stop fluid in your eye from draining properly. This causes pressure in the eye to build. This pressure can damage the nerve that carries images from your eye to your brain (optic nerve).
• Blindness — diabetic retinopathy and glaucoma can lead to complete vision loss, especially if these conditions are poorly managed.

While treatment can slow down the damage to your eye and stop new damage from happening it:

• does not cure diabetic retinopathy
• does not usually restore your vision to what it was before.

It is important to keep good control over your blood glucose (sugar) levels. 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.

There are 2 main types of laser treatment.

1. Focal laser treatment will treat just one spot in your retina.
2. Panretinal photocoagulation is laser treatment that treats a wider area of your retina. This helps to slow down or stop any further damage.

Injections

Some medicines can help to reduce:

• the growth of abnormal blood vessels
• the amount of fluid leaking from them.

These medicines include Avastin (bevacizumab), Lucentis (ranibizumab) and Eylea (aflibercept).

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These medicines can be injected into your eye after it is 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.

You can reduce your risk of diabetic retinopathy by:

• keeping your diabetes as well managed as possible
• having regular diabetic eye checks
• having treatment for high blood pressure (hypertension) and high cholesterol if you have these conditions — they 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. 

Quitting smoking

Find more information and short videos about treatments for diabetic retinopathy. 

Diabetic retinopathy — American Academy of Opthalmology