Diabetic retinopathy

What is diabetic retinopathy?

Diabetic retinopathy is a serious, sight-threatening complication of diabetes, and the most common cause of vision loss for people living with diabetes. It's caused by damage to the tiny network of blood vessels that supply oxygen and nutrients to the retina, the light-sensitive tissue at the back of the eye.

Anyone with any type of diabetes (type 1 or type 2) can develop diabetic retinopathy – and their risk will increase the longer they have diabetes. If the condition is left undiagnosed and untreated, it can lead to blindness. However, it usually takes several years to reach a stage where it could threaten a person’s sight.

What causes diabetic retinopathy?

Diabetes affects how the body regulates blood glucose (sugar) levels, and if blood sugar levels are consistently high, blood vessels throughout the body can become damaged, which can result in serious complications. Diabetic retinopathy is caused by damage to the tiny network of blood vessels in the retina.

The retina is the tissue at the back of the eye that converts light into electrical signals. These signals are then sent to the brain and interpreted into the images that we see. When these blood vessels are damaged, they can get blocked, leak, or grow incorrectly. As a result of these changes, the retina can’t get hold of enough oxygen and nutrients it needs to work properly, leading to sight loss.

Not everybody with diabetes develops retinopathy. But it is one of the most common complications of the condition – and the longer you’ve had diabetes, the greater the chance of developing it. Within 20 years of diagnosis, nearly everyone with diabetes will be affected to some degree.

People whose diabetes is well managed are less likely to develop retinopathy than those whose blood sugar, blood pressure and cholesterol levels are poorly controlled. Those who smoke are at higher risk.

Proliferative diabetic retinopathy tends to be more common in people with type 1 diabetes than type 2. People of African-Caribbean or South Asian heritage are about twice as likely to develop sight-threatening diabetic retinopathy as people of white European heritage.

What are the signs and symptoms of diabetic retinopathy?

Your vision isn’t usually affected during the early stages of diabetic retinopathy, but as the condition progresses, you may notice gradually worsening vision, such as blurred or patchy eyesight, and you may have trouble reading or seeing distant objects. These changes may come and go.

You may find that colours aren’t as clear and vibrant as they used to be, and may see an increasing number of floating shapes or dark spots in your field of vision. It may be harder, or take longer, to adjust to the dark or dim light.

Any eye pain and/or redness should be assessed immediately, as it could be a sign of serious complications. 

Retinal detachment is a rare complication of diabetic retinopathy, but when it occurs, symptoms can come on suddenly and dramatically. This may involve a dark ‘curtain’ moving across the field of vision, a sudden dramatic increase in floaters, or seeing flashing lights. Retinal detachment is a medical emergency that should be assessed urgently.

Is diabetic retinopathy serious?

If the condition is left undiagnosed and untreated, it can lead to blindness. Managing diabetes well is the best way to lower the risk of developing the condition or help stop it from progressing. In the later stages of the disease, treatments, including eye injections and laser surgery, can help stop a person’s vision from getting worse.

How is diabetic retinopathy diagnosed?

In the UK, everybody with diabetes is offered regular health checks to monitor how well their condition is being managed and pick up any early signs of problems. This includes annual eye examinations (diabetic eye screening) to check for eye problems caused by diabetes.

Attending these diabetic eye screening appointments is the most effective way to prevent sight loss due to retinopathy. Early detection and treatment can help stop you from losing your vision.

During a screening appointment, eye drops will be applied to temporarily dilate (widen) the pupils before a special camera is used to take photographs of the back of the eye. Depending on the findings, more regular monitoring may be advised, or you may be referred for further tests and treatment.

What are the treatments for diabetic retinopathy?

The most important way to prevent further blood vessel damage and prevent diabetic retinopathy worsening is by keeping your diabetes under control. Taking steps to maintain your blood sugar levels at target levels can help stop any vision problems from developing or getting worse.

Diabetic retinopathy usually only requires specific treatment when it has reached an advanced stage, and there’s a risk to a your vision. The main treatments include eye injections (anti-VEGF drugs), laser treatment, steroid implants and surgery.

These treatments can’t always undo any damage to the retina that’s already occurred. There is also a risk of side effects, which can range from temporary irritation and blurred vision to permanent sight loss.

What can help diabetic retinopathy?

The best way to reduce the risk of developing diabetic retinopathy, or stop it from getting worse, is by controlling blood sugar levels, blood pressure and cholesterol levels. This can often be achieved by making healthy lifestyle choices along with taking any prescribed medications.

Things you can do to help keep your eyes healthy if you have diabetes include:

• Regular physical activity
• Eating a healthy, balanced diet
• Stopping smoking
• Maintaining a healthy weight
• Taking any medications to help control blood sugar levels, blood pressure and cholesterol levels as prescribed
• Attending regular diabetic eye screening appointments
• Telling their doctor about any changes to your sight

What research is there into diabetic retinopathy?

Fight for Sight’s goal is to understand more about the processes that cause diabetic retinopathy and develop new treatments for tackling damage to help save thousands of people from diabetes-related sight loss.

We are working with partners to fund research projects into diabetic retinopathy. Key areas include understanding more about how diabetes causes blood vessels to become leaky and investigating any detectable changes within the retina that may occur before blood vessel changes develop. Research to develop more effective treatments to prevent and target complications associated with diabetic retinopathy is also underway.

For example, we are currently funding a team at University College London that is investigating the role of a molecule called Galectin-1 in retinal blood vessel disorders. This research could ultimately lead to new treatments that can help slow down sight loss in patients with diabetic retinopathy.

See our research projects

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