This is a complication which occurs when diabetes causes the retina to become damaged. Diabetes is a condition that occurs when the body cannot control blood sugar levels and there are two types of diabetes, type 1 and type 2. Type 1 diabetes develops when an individual cannot produce insulin to control the level of glucose in the blood. Type 2, which is much more common, develops when insufficient insulin is made or the insulin does not function properly, causing blood sugar levels to be abnormal. Retinopathy is a common complication resulting from diabetes and all patients diagnosed with diabetes are advised to have regular eye tests.
The retina is located at the back of the eye and is made of special cells called rods and cones. When light enters into the eye the rays are refracted by the cornea, focused by the lens and projected onto the retina. Information about the image is then sent from the retina to the brain via the optic nerve. Retinopathy is a term used to describe damage to the retina and in most cases it involves damage to the small blood vessels at the side of the retina.
If diabetes is poorly controlled it can cause damage to the retina, known as retinopathy. Over time high levels of blood glucose can cause damage to the tiny blood vessels, which are located at the side of the retina. This can contribute to a range of different problems affecting the eyes, including:
In most cases people do not experience symptoms of retinopathy. However, if diabetes is poorly managed the condition can become worse and it may cause a loss of vision and even blindness. Diabetic retinopathy is among the most common causes of blindness in young people in the UK.
Some people do experience symptoms of diabetic retinopathy, including:
Retinopathy can affect different parts of the eye. If the macula (located in the centre of the retina) is affected this tends to be serious. If the peripheral part of the retina is affected this usually causes no symptoms or mild symptoms.
Retinopathy is usually progressive, meaning it tends to get worse over a period of years. Here is listed the diabetic retinopathy stages:
If fluid leaks into the macula this can cause macular oedema (inflammation of the macula), which causes vision to become blurred. A macular oedema is treated with laser treatment.
If proliferative retinopathy becomes very serious and a lot of new vessels develop, this can cause severe damage to the retina and scarring, and it may also cause the retina to become detached. If you have high blood pressure, as well as diabetes, the risk of suffering severe retinopathy is higher.
Anyone who has diabetes has a risk of developing diabetic retinopathy, though it tends to affect people with type 1 diabetes more commonly than those with type 2 diabetes. Risk factors include:
Diabetic retinopathy can be discovered during eye examinations. Your optometrist will examine your eyes and check for signs and symptoms of diabetic retinopathy. If your optometrist notices symptoms you will be referred to an eye specialist (known as an ophthalmologist), who will carry out further tests to confirm a diagnosis and draw up a treatment plan.
The NHS runs a diabetic retinopathy screening programme for all patients over the age of 11 with diabetes, which involves annual checks for signs of retinopathy. The tests involve examining the back of the eye (the retina), checking your vision and taking photographs of the retina. During the test drops will be placed in the eyes to dilate the pupils, which allow the optometrist or doctor to see more clearly.
A test called a fluorescein angiogram may also be carried out and involves injecting a coloured dye into a vein in the arm. The dye travels to the eyes via the blood vessels and a camera is then used to detect any abnormalities in the vessels, leakage from vessels or swollen vessels.
If you notice any changes in your vision before you are due to have an eye test, you should see your GP or our optometrist as quickly as possible.
If you have mild retinopathy you may not need treatment, but your doctor will keep an eye on you to monitor your eyesight and check for signs that the condition has developed. If you have severe retinopathy and new blood vessels have grown (proliferative retinopathy), the most common treatment is laser eye surgery.
Laser treatment works by using intensive laser beams to seal the blood vessels closed, which prevents leaking and bleeding and also stops any more abnormal new vessels forming. It is common for laser treatment to be administered over the course of several sessions. The type of laser treatment will depend on the individual patient. Laser treatment is usually very successful at preventing further harm to the retina; however, it cannot improve sight that has already been lost.
After laser treatment it is common for your sight to be a little blurred, but it should return to normal after a few days.
If the retina has become detached then surgery will be required. An operation may also be recommended if a vessel has leaked blood into the vitreous humour of the eye, which is known as a vitrectomy. This involves making a miniature incision in the eye and removing the vitreous gel that has been contaminated by blood with a special instrument, after which the vitreous gel is then substituted with a salt compound.
Research into treatments for diabetic retinopathy is ongoing.
It may not be possible to prevent diabetic retinopathy, but there are things you can do to reduce the risk or slow down the progress of symptoms. These include: