Diabetic retinopathy

Suzie Bushby, from Chichester, who was diagnosed with diabetic retinopathy, said:

“I’ve had diabetic retinopathy for four years which has really had a significant impact on mine and my family's life. This has involved seven bouts of laser treatment, a detached retina and six months off work. Research gives me hope for the future because it paves the way for understanding the disease and developing new treatments that could make a real difference.”

Find out how the diabetic retinopathy research we fund will have a huge impact for people like Suzie who are living with the condition.

More about our research

What is diabetic retinopathy?

Diabetic retinopathy is a form of sight loss that can develop in anybody with type 1 or type 2 diabetes, as a result of damage to blood vessels supplying the retina - the light-sensitive layer at the back of the eye.

There are different types and stages of diabetic retinopathy, which can vary in severity and, in some cases, lead to blindness. It is one of the most common cause of sight loss among working-age adults in the UK. With rates of diabetes on the rise this figure is expected to increase. 

Managing diabetes well can help prevent diabetic retinopathy and if detected early enough, treatments including injections and laser surgery can help. But in the early stages blood vessel damage doesn’t always cause noticeable symptoms. So it may go undetected until the problem gets worse, which means complications and permanent sight loss can still occur. This is why funding vital research into diabetic retinopathy plays a big part in our mission to create a future everyone can see. 

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

What causes diabetic retinopathy?

Diabetes affects how the body regulates blood sugar (glucose) levels. When these are too high, blood vessels throughout the body can become damaged, which can result in serious complications.

Diabetic retinopathy results from damage caused by diabetes to the blood vessels that supply oxygen to the retina – which is responsible for converting light passing through the eye into the signals sent to the brain that enable us to see. However, exactly how and why these changes happen is not yet fully understood.

The three main stages of diabetic retinopathy are:

  • Stage 1: Background diabetic retinopathy
    Background diabetic retinopathy is the earliest detectable stage, when small swellings develop in the capillaries (tiny blood vessels). These don’t normally affect vision but monitoring them closely is important.

  • Stage 2: Pre-proliferative diabetic retinopathy
    At this stage more widespread changes are seen in the retina, including severe bleeding into the retina. There is a high risk that your vision could eventually be affected.

  • Stage 3: Proliferative diabetic retinopathy
    This is an advanced stage of diabetic retinopathy, which develops when blood vessels have become severely blocked or damaged. In response, the body begins to produce new blood vessels - but these are often very weak and prone to bleeding, which can cause scarring to form. Leaked blood can also block light from reaching the retina, resulting in sight loss. Proliferative diabetic retinopathy can sometimes lead to retinal detachment, where the retina peels away from the back of the eye.

  • Diabetic maculopathy
    If these swellings worsen, blood vessels can begin to leak. Diabetic maculopathy occurs when leaking fluid has damaged the macula – a tiny collection of light-sensitive cells at the centre of the retina. The macula is crucial for central vision and seeing detail and colour, so macula-related sight loss can have a big impact.

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 also tends to be more common in people with type 1 diabetes than type 2. And ethnicity can play a role: People of Afro-Caribbean and South Asian heritage are about twice as likely to develop sight-threatening diabetic retinopathy as white Europeans.

What are the signs and symptoms of diabetic retinopathy?

Vision isn’t usually affected during early stages of blood vessel damage. If the condition worsens, how it affects vision can vary from individual to individual.

When diabetic retinopathy does cause symptoms, they may include:

  • Reduced central vision. This may be mild to begin with but can gradually worsen over time. Vision may become blurred and patchy, which might be most noticeable with tasks that involve seeing detail - like reading, watching TV and using a computer – due to damage affecting the macula.
  • Changes in colour perception. People may notice colours aren’t as clear and vibrant as they used to be.
  • Floaters. An increase in floating shapes or dark spots in your field of vision can also occur.
  • Eye pain. Diabetic retinopathy doesn’t always cause pain but any eye pain and/or redness should be assessed immediately, as it could be a sign of serious complications.
  • Sudden severe sight loss or vision changes. Retinal detachment is a rare complication of diabetic retinopathy, but when it occurs symptoms can come on suddenly. This may involve a dark ‘curtain’ moving across your field of vision, or a sudden dramatic increase in floaters or seeing flashing lights. Retinal detachment is a medical emergency that should be assessed urgently.  

How is diabetic retinopathy diagnosed? 

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

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

How is diabetic retinopathy treated? 

How diabetic retinopathy is treated depends on the severity of the condition. First and foremost, the focus is on preventing blood vessel damage through good diabetes management. Even if early signs of damage are detected during a routine screening, taking steps to better control blood sugar levels can help stop problems from getting worse.

If treatments are required, they may include: 

  • Eye injections
    Anti-VEGF injections can be used to treat diabetic maculopathy. Local anaesthetic is used to numb the eyes, before the treatment is administered by a specialist via a very fine needle. As well as preventing further damage, when suitable, anti-VEGF injections may help restore sight loss that’s already occurred in some patients.

  • Laser treatment
    Lasers can be used to treat new weak blood vessels that develop as a result of diabetic retinopathy. The laser can help seal and remove the damaged vessels, preventing them from bleeding and causing further sight loss. This is usually carried out as an outpatient procedure, with local anaesthetic used to numb the eyes first.

  • Surgery
    In severe cases, surgery may be required. This may include surgery to repair a detached retina, or vitreoretinal surgery to remove some of the vitreous humour (the clear jelly-like substance that fills the space between the lens and the retina). This may be required if leaky blood vessels have resulted in significant bleeding, resulting in scar tissue, blockages and a high risk of retinal detachment. Surgery is carried out under general anaesthetic and involves a specialist surgeon making a small incision in the eye.

However, treatment can’t always undo damage that’s already occurred. Side-effects can occur too, ranging from temporary irritation and blurred vision, to permanent sight loss.

What research is underway? 

Fight for Sight’s goal is for a new treatment to be developed within the next ten years. 

Diabetic retinopathy is already the most common cause of sight loss in working-age UK adults – and rates are expected to rise. 

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 currently working with partners to fund 50 research projects into eye disease linked to other conditions, like 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, Fight for Sight is funding a team at Queen’s University Belfast who, for the first time ever, are using single cell RNA sequencing to simultaneously ‘dissect’ all the cell types within the retina. This will help us to discover more about how cells are affected during the course of diabetic retinopathy, potentially enabling development of new treatments in the future to prevent sight loss by tackling the early stages of the condition.

Read more about our diabetic retinopathy research

What can I do?

For anybody with diabetes, managing the condition well can help prevent problems including diabetic retinopathy from developing. Alongside any medication when required, this involves following a healthy lifestyle with a balanced diet and regular exercise, not smoking, and monitoring blood sugar levels with the aim of keeping them stable. There’s lots of support available to help with managing diabetes - your GP can point you in the right direction.

Attending annual diabetic eye screenings is vital – the tests can detect early signs of damage before sight loss occurs. Regardless of when your last screening was however, if you notice any vision changes, it is always best to get things checked immediately. Any sudden or severe symptoms should be treated as a medical emergency.

Last update June 2019
Approved by Dr David Simpson, Queen's University Belfast

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