Diabetic retinopathy doesn't usually cause any noticeable symptoms until it has reached an advanced stage.

If retinopathy is not identified and treated, it can lead to sudden blindness.

This is why it's very important to attend regular screening appointments if you have diabetes.

Other symptoms of advanced retinopathy can include:

• shapes floating in your field of vision (floaters)
• blurred vision
• sudden vision loss

When to seek medical advice

If you have diabetes, you are 20 times more likely to develop vision problems than the rest of the population. Therefore, it's vital that you take any problems with your eyes seriously.

Contact your GP or diabetes care team immediately if you experience any of the symptoms listed above, or if you have any new problems with your eyesight.

Stages of diabetic retinopathy

The signs and symptoms of diabetic retinopathy become more serious as the condition progresses through the following stages:

• Stage one: background retinopathy – tiny bulges (microaneurysms) appear in the blood vessels of your eye, which can leak blood.
• Stage two: pre-proliferative retinopathy – more severe and widespread changes are seen in the retina, including bleeding into the retina.
• Stage three: proliferative retinopathy – new blood vessels and scar tissue will have formed on your retina, which can cause loss of vision.
• Stage four: advanced diabetic retinopathy – this can cause either bleeding into the eye, resulting in sudden loss of vision (vitreous haemorrhage), or retinal detachment (when the retina pulls away from the back of the eye).

Read more about the causes of diabetic retinopathy.

Diabetic maculopathy

People with diabetes may also suffer from changes to the blood vessels in the macula, which is the central area of the retina.

When the blood vessels in the macula are affected, this is known as diabetic maculopathy.

The vessels in the macula can become leaky and the blood pressure can force fluid, fats and protein out of the bloodstream and into the retina. This is known as macular oedema and causes some loss of vision in most cases.

Injection therapy can be given for severe cases of macular oedema (whereas oedema outside of the macula can be treated by laser). 

Occasionally, the blood vessels in the macula become so narrowed that the macula is starved of oxygen and nutrition, causing your sight to get worse. This is called ischaemic maculopathy and does not usually respond to any type of treatment.