Health Centres - Diabetic retinopathy (eye disease)
Diabetic retinopathy is an eye disease that's associated with long-standing diabetes. It's a major cause of poor vision in the UK.
Retinopathy can occur with all types of diabetes. If left untreated, diabetic retinopathy can lead to blindness.
What causes diabetic retinopathy?
The longer a person has diabetes, the higher their chances of developing diabetic retinopathy.
Prolonged periods of high blood sugar levels cause damage to the small blood vessels in the retina at the back of the eye.
These blood vessels initially become leaky, and then may become blocked off.
This causes haemorrhages (spots of blood) and exudates (proteins) from the blood vessels on to the retina. It may also cause swelling, known as oedema of the retina.
The blocked vessels can starve the retina of oxygen, leading to the growth of new abnormal vessels from the retina.
Good control of diabetes by controlling the blood sugar level helps to reduce the chances of developing retinopathy.
What are the different types of diabetic retinopathy?
It can be classified in different ways, but there are three main types:
- background retinopathy
- maculopathy
- proliferative retinopathy.
These are not different diseases, but are different stages of the same condition. This means the type you have may change as the disease progresses.
Maculopathy
In maculopathy, the haemorrhages, exudates and swellings of the first stage occur in the macula. This may interfere with vision, particularly for reading and seeing fine details.
Proliferative retinopathy
These blood vessels are fragile and may:
- bleed into the eye (vitreous haemorrhage)
Both these complications would cause a reduction in vision. If the blood vessels were left untreated, it could eventually lead to blindness.
Proliferative retinopathy causes no symptoms until it is very advanced. If a vitreous haemorrhage develops, it can cause sudden loss of vision in one eye.
How is it diagnosed?
Until diabetic retinopathy is at a very advanced stage, vision is not usually affected. This means it's usually detected by routine checks, making regular eye examinations a must for people with diabetes.
Early diagnosis will also help treatment.
Everyone with diabetes should have their eyes examined each year. This may be carried out by the doctor who looks after your diabetes, your GP, or through local programmes that use an optician or diabetic screening eye vans.
If there is any evidence of retinopathy picked up, you will be referred to an eye clinic. The frequency of follow-up then needed depends on the extent of the retinopathy.
What are the risk factors?
- with poor blood sugar control, ie levels are too high for too much of the time
This list has some things in common with that for diabetic kidney disease.
The area of the retina we use most is called the macula. It is essential for clear, detailed vision.
At this stage, some of the tiny blood vessels in the retina become blocked. In response to the lack of blood in the retina, new abnormal blood vessels grow.
- stimulate abnormal supporting tissues that can cause the retina to detach.
Diagnosis is made by examining the back of the eye (retina).
There is an increased risk of retinopathy:
- if there's protein in your urine
- if you have high blood pressure
- the longer you've had diabetes
- if you have raised levels of fats (triglycerides) in the blood
- the more swellings you have (microaneurysms)
- with pregnancy (but not in diabetes caused by pregnancy).
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