Diabetes is becomingly increasingly common in the UK, with an estimate of around four million people suffering from the condition, 90 percent of whom have Type 2 (caused by insulin resistance).
So why is it so important for anyone who has or suspects they may have diabetes to have their sight checked? This is because they are at risk of diabetic retinopathy, which occurs when high blood sugar levels get to the point of damaging the back of the eye (the retina).
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How it happens
The light-receiving retinal layer at the back of the eye needs a constant supply of blood which it receives through a network of tiny blood vessels. The high blood sugar level caused by diabetes effects the retina in three stages:
Bulges appear in the blood vessels which cause them to bleed slightly, although this doesn’t usually affect the vision.
More damage is caused to the blood vessels, causing more bleeding.
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The scar tissue and new blood vessels are weak and end up bleeding more easily. This damage can spread to the retina and cause loss of vision.
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Are you at risk?
Everyone who has diabetes is at risk, of diabetic retinopathy, and should get their eyes screened once a year. People who suffer from Type 2 diabetes can usually keep the risk low by working hard to keep their blood pressure levels under control. People may be at a higher risk if:
• They have had diabetes for a long time
• They have a constant high level of blood glucose
• They have a high cholesterol level
• They are pregnant
Symptoms
Diabetic retinopathy doesn’t usually show in the very early stages, which is why it is very important to get regular eye screenings, as this is often the only way to see whether it is developing and put treatment in place to prevent further damage. However, if you are diabetic, there are certainly symptoms to look out for to make sure you get treated as soon as possible. Such as:
• Gradually worsening vision
• Sudden vision loss
• Shapes floating in your vision
• Blurred or patchy vision
• Eye pain, swelling or redness
What is a diabetic eye screening?
The eye screening procedure consists of having photos of the retina taken using an ophthalmic imaging system. First, the patient is given eye-drops to make the pupils bigger (dilate them)—this can cause the eyes to sting and water for some hours. The flash from the photographic equipment can also be uncomfortable for a moment. After the examination, patients should not drive, as their eyesight will be affected for some hours.
On the NHS, results will take a couple of weeks to come through, and will be sent to the patient and their GP. The photographic image will show a trained ophthalmologist whether there is any evidence of diabetic retinopathy.
Although a simple procedure, this testing procedure can make a huge difference to the number of people who go blind in the UK. In 2017, the NHS founds that the proportion of diabetics who go blind had halved since a new retinopathy screening programme started in 2007.
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How to reduce the risk
There are several measures that people can take to reduce their risk of diabetic retinopathy. The main one is to keep diabetes symptoms under control, by checking blood sugar and blood pressure levels at home and throughout the day. It’s also important to manage high cholesterol levels by getting regular blood tests carried out by your GP.
Health professionals say that diabetics who maintain a healthy lifestyle are not nearly as likely to get diabetic retinopathy. This includes eating a healthy and balanced diet, as well as exercising regularly. It is also important to stop smoking and to not exceed the recommended alcohol limits.
Treatment
Treatment is usually only offered when the condition has reached an advanced level and taking these precautions will no longer help. If the retinopathy gets to this advanced stage, laser treatment is often used to treat the growth of new blood vessels developing at the back of the eye. This can also stabilise some cases of maculopathy, which is damage to the macula (centre of the retina. Eye injections can also be used to treat retinopathy that is starting to threaten the sight. When the condition becomes too advanced for laser treatment or injections, then surgery is a last resort, to remove blood or scar tissue from the eye, but with increasing awareness of the condition, hopefully fewer people will get to that stage.
This feature was originally published in the winter edition of Live to 100 with Dr Hilary Jones, which you can read here
