Diabetic Retinopathy

Diabetes is a condition whereby the body cannot process sugar or other carbohydrates.  We need a hormone called insulin, which is produced in the pancreas, to process carbohydrates and regulate our blood sugar levels.  Diabetes occurs when there is a lack of insulin in the body.

There are two main types of diabetes:

Type 1 commonly occurs before the age of 30 and is due to the pancreas producing little or no insulin at all.  People with diabetes need regular insulin injections.

Type 2 is more common over the age of 40 and is due either to a lack of insulin or to the body not using insulin efficiently.  People with Type 2 diabetes can control their condition in several ways – some people can control their diabetes just by changing their diet and cutting out or cutting down on certain foods.  Others may also need tablets to help stabilise their blood sugar levels.  Sometimes insulin injections will still be required in Type 2 diabetes.

It is important to have regular checks on your blood sugar levels if you are diabetic to ensure adequate control.

Diabetic Retinopathy

Diabetes affects the blood vessels throughout the body, and as such there are many complications associated with diabetes.  When it affects the small blood vessels in the retina of the eye it is known as Diabetic Retinopathy.

Our new optomap® system can help to detect diabetic retinopathy, and we will discuss any changes we find with you.  You can find out more information about the optomap® system here. (link to optomap page)

There are different stages of diabetic retinopathy, and we allocate a grade depending on the severity.

Non-proliferative Diabetic Retinopathy

In this stage the walls of the small blood vessels bulge slightly to give microaneurysms – they look like small red dots on the retina.  The blood vessels may also leak fluid, exudates or blood.  A grade is allocated depending on the quantity of these we see.

There may also be venous beading and dilatation, where the larger blood vessels appear thicker and irregular, or IRMA which are abnormalities in the blood vessels.  These are more severe and so are allocated a higher grade.  People with these signs are more likely to go on to develop proliferative diabetic retinopathy.

Proliferative Diabetic Retinopathy

As diabetic retinopathy progresses, new blood vessels start to grow at the retina of the eye.  This happens because the damaged blood vessels cannot supply enough oxygen to the cells of the retina; new blood vessels are grown to improve the oxygen supply (neovascularisation).  Unfortunately, these new blood vessels are much weaker than our normal blood vessels.  They grow on the surface of the retina and into the vitreous gel.  They bleed very easily causing haemorrhages within the vitreous gel.  This can have a very sudden and very dramatic effect on the vision, causing blurring or blank patches in the vision.  This can also lead to scar tissue which can pull on the retina and cause a retinal detachment.

The new blood vessels themselves do not usually affect the vision, but the complications they cause can have a very sudden and very serious effect on the vision.  Without treatment, proliferative diabetic retinopathy can lead to a total loss of vision.

Maculopathy

The macular area of the retina is the part of the eye responsible for detailed, central vision.  If this area is affected by diabetic retinopathy, even if there are only small changes, it can affect your vision.  Blood vessels can leak and bleed to cause macular oedema (swelling) which distorts or blurs your vision.  If you are diabetic and notice a reduction in your vision, it is important to have a prompt assessment to check this area of the retina.

Diabetic Retinopathy Screening

Diabetic retinopathy does not usually affect vision until it is quite advanced.  Research has shown that early detection of diabetic retinopathy and early treatment is much more effective than waiting until the vision has been affected.  As such, Diabetic Retinopathy Screening is carried out throughout the UK.  This helps to identify early problems before they start to impact on the vision, meaning that any necessary treatment can be carried out earlier and more effectively.

Diabetic retinopathy screening involves taking detailed photographs of the retina of the eye and monitoring it for any changes.  In Cirencester, these photographs are taken at your GP surgery – mobile units visit regularly to carry this out.  In Swindon, screening is carried out at designated diabetic retinopathy screening centres.  This is not the same as your normal eye examination so it is important to attend your diabetic retinopathy screening appointments on an annual basis.

Treatment

If treatment is needed, it is usually laser treatment that is recommended.  This aims to destroy the areas of the retina that have been damaged, reducing the oxygen demand.  As the retina does not then need as much oxygen, the new blood vessels stop growing.  This helps to protect the undamaged areas of the retina that remain, and thus helps to preserve vision.  Laser treatment cannot usually restore vision that has already been lost so it is essential that any necessary treatment is carried out before the sight is affected.

Who is at risk of developing diabetic retinopathy?

The main things that increase the likelihood of developing diabetic retinopathy are:

• The length of time you have had diabetes.  The longer you have been diabetic the more likely you are to develop any complications including diabetic retinopathy.
• Poor control of blood sugars.  If your blood sugar is high or very variable you are much more likely to develop diabetic retinopathy.
• Poor control of blood pressure.  High or variable blood pressure increases your risk of developing diabetic retinopathy almost as much as high or variable blood sugars.
• Pregnancy.  The hormonal changes in pregnancy can cause very quick changes to your eyes and you can develop diabetic retinopathy very quickly.  If you are diabetic and thinking of having a baby, be sure to discuss this with your GP.  Diabetic retinopathy screening is carried out more often during pregnancy and is often carried out in the hospital system – your GP will ensure you are given the correct care.

Reducing the risk

You can help to prevent the development of diabetic retinopathy by:

• Keeping your blood sugar well under control.
• Keeping your blood pressure well under control.
• Attending your diabetic appointments with your GP or diabetic nurse to monitor your diabetes.
• Stopping smoking.
• Attending regular eye examinations, including your diabetic retinopathy screening appointments.

Other eye problems

Diabetes can also affect the eyes in other ways: