A common complication of diabetes is damage to the back of the eye (retina). This is known as diabetic retinopathy, the most common form of diabetic eye disease.
While treatable, diabetic retinopathy becomes particularly dangerous when left untreated, often causing some loss of vision and even blindness, in severe cases.
According to the NHS, 1,280 new cases of blindness caused by diabetic retinopathy are reported each year in England alone, while a further 4,200 people in the country are thought to be at risk of retinopathy-related vision loss.
Keeping blood glucose levels and blood pressure well controlled helps to lower the risk or slow the progression of diabetic retinopathy.
What is diabetic retinopathy?
Diabetic retinopathy is the term used to cover various disorders of the retina - the thin layer of light-sensitive tissue that lines the back of your eyes - brought on by long-term diabetes. These disorders can affect eyesight and increase the risk of total loss of vision.
*Note that while the common cause of retinopathy is diabetes, it can sometimes be caused by other diseases such as hypertension (high blood pressure).
How is diabetic retinopathy caused?
Diabetic retinopathy is caused by prolonged high blood glucose levels. Over time, high sugar glucose levels can weaken and damage the small blood vessels within the retina, the part of the eye that sends messages about what we see to the brain.
This can lead to a number of different problems, including:
- Microaneurysms - Swelling of blood vessels
- Exudates - Small leaks of fluid from damaged blood vessels
- Haemorrhages - small bleeds from damaged blood vessels
- Blockages - Blocked vessels can starve the retina of blood and oxygen, causing weak new blood vessels to grow on the surface of the retina
Types of diabetic retinopathy
The problems listed show how diabetic retinopathy gradually becomes more serious and progresses from tiny swellings (background retinopathy) of the retinal blood vessels to blockages and bleeding (proliferative retinopathy), which can seriously affect vision and eventually cause blindness.
In addition to background retinopathy and proliferative retinopathy, there is another type of retinopathy known as diabetic maculopathy.
Background retinopathy, also known as simple retinopathy, involves tiny swellings in the walls of the blood vessels. Known as blebs, they show up as small dots on the retina and are usually accompanied by yellow patches of exudates (blood proteins).
Cases of background diabetic retinopathy need to be monitored by an ophthalmologist.
This stage of diabetic retinopathy refers to the progression of background retinopathy into small central part of the retina called the macula. The macula is the most well used area of the retina as it plays an essential role in helping you focus see things directly in front of you (central vision). Therefore, damage to this part of the eye can cause serious vision problems.
Proliferative retinopathy is an advanced stage of diabetic retinopathy in which the retinal blood vessels become blocked, causing the growth of abnormal blood vessels. Because these tiny new vessels are delicate, they can easily break and bleed into the eye, obstructing vision. In severe cases, they can cause the cause the retina to detach, resulting in serious sight loss and blindness.
In the case of a vitreous haemorrhage, where damaged blood vessels bleed into the jelly-like centre of the eye (the vitreous humour), the loss of vision can be instant.
Retinopathy occurs when blood vessels in the back of the eye, the retina, become damaged. When the blood vessels become damaged they can leak and these leaks can cause dark spots on our vision.
The main causes of retinopathy tend to be sustained high blood glucose levels and high blood pressure as well. Retinopathy can progress over years or decades depending on how good your blood glucose control is.
The good news is that because it takes a long time to develop, it can be spotted before it becomes too serious.
The symptoms of retinopathy tend to come on once retinopathy has been developing for some time. The symptoms present themselves as dark patches on your vision. You may not notice them at first but can be more noticeable if retinopathy is not picked up.
It’s important therefore that you attend your retinopathy screening each year.
People with diabetes should be screened in the UK once each year for retinopathy. A photograph is taken of the eye which allows the specialists to spot any signs of damage that may be present.
Screening appointments mean that the signs can be spotted well in advance of symptoms developing. In the early stages of retinopathy, no treatment is needed but it’s recommended that patients keep good control of their blood sugar levels.
If retinopathy develops laser surgery may be needed. Laser targets the problem blood vessels to prevent them from leaking. Other treatments for advanced retinopathy can include injections or vitrectomy surgery.
What are the symptoms of diabetic retinopathy?
Like many conditions of this nature, the early stages of diabetic retinopathy can occur without symptoms and without pain.
Symptoms may only become noticeable once the disease advances, but the typical symptoms of retinopathy to look out for include:
- Sudden changes in vision / blurred vision
- Eye floaters and spots
- Double vision
- Eye pain
Read more about the symptoms of diabetic retinopathy.
Am I at risk from diabetic retinopathy?
Diabetic retinopathy risk factors include the following.
If any of the below affect you it’s worth having an retinopathy screening examination as quickly as possible.
- Poor blood glucose control
- Protein in urine
- High blood pressure
- Prolonged diabetes
- Raised fats (triglycerides) in the blood
- Increased swellings
- Pregnancy (not gestational diabetes)
Anyone suffering from diabetes faces the risk of developing diabetic retinopathy and other diabetes complications.
The longer a person has diabetes, the greater the risk of developing diabetic retinopathy becomes.
Are there any ways to prevent diabetic retinopathy?
Long-term good blood glucose level management helps to prevent diabetes retinopathy and lower the risk of developing it. Heart disease risk factors also affect retinopathy risk and include stopping smoking, having regular blood pressure and cholesterol checks and undergoing regular eye check-ups.
The risk of developing diabetic retinopathy can be lessened through taking the following precautions:
- Taking a dilated eye examination once a year
- Managing diabetes strictly through medicine, insulin, diet and exercise
- Test for blood sugar levels regularly
- Test urine for ketone levels regularly
Can diabetic retinopathy be treated?
Laser surgery is often used in the treatment of diabetic eye disease, but each stage of diabetic retinopathy can be treated in a different way.
- Mild background retinopathy does not usually require any treatment although patients will need to have regular eye examinations and keep tight control of risk factors such as blood glucose, blood pressure, and cholesterol levels.
- Diabetic maculopathy is usually treated with laser treatment (tiny burns that destroy small damaged areas of retina). This is usually painless and has no side effects, but can influence night driving and peripheral vision.
- Proliferative retinopathy is also treated with lasers in order to seal leaks from blood vessels, and stop further growth of new, abnormal vessels.
While laser treatment for diabetic retinopathy is usually effective at preventing eyesight deterioration and loss of vision, it cannot restore vision that is already lost. For serious cases of diabetic retinopathy, such as retinal detachment or vitreous haemorrhage, or cases where last treatment has proven ineffective, eye operations may be required.
What the community are saying about diabetic retinopathy
- Jude: I had my yearly eye screening last month and was told that they can just see some retinopathy developing but at the moment it does not need treatment as it is very slight. I was more dismayed with this information because I struggle so much with my glucose numbers and now I am getting complications setting in. Anyway the technician explained to me that if/when it needs treatment they give laser treatment which halts the progression of the retinopathy.
- Anniep: Keeping your BG low is the best way of avoiding complications, my mum was insulin dependent for nearly 40 years, and when she died at 80 she was complication free. But don't be fooled by anybody downplaying the seriousness of diabetic retinopathy.
- Sid Bonkers: I had a retinal scan after diagnosis that showed background retinopathy, two months later whilst having an eye test the optician told me he could see no evidence of background retinopathy. At my second scan I was shown that the background retinopathy that was spotted a year before was still there but that there was no further bleeds.
- Noblehead: My Ophthalmologist stressed after I developed diabetic retinopathy 10 years ago, that keeping blood glucose, blood pressure and cholesterol levels below normal will help prevent or delay the onset of complications due to neuropathy and retinopathy, hence why I monitor them closely and test my blood pressure once a week on my home blood pressure monitor.
- Clp: I had a screen for retinopathy last week and when the picture was taken the lady said it was fine, so I went away quite happy. However, yesterday I got a letter from the hospital saying that my eyes were showing some signs of background retinopathy. This scared me half to death but also confused me. Reading up on it it's usually 5 years before plus before you start to show signs of retinopathy so now I'm wondering have I been diabetic for longer than I thought.
What is vision like when you have diabetic retinopathy?
Diabetic retinopathy will damage your vision if it is not treated. The video below highlights how dark patches may affect your vision.