Derby Eye Surgery
Diabetic Eye Disease

What is diabetes?

All tissues in the body require glucose for energy. The amount of glucose entering any tissue has to be controlled and this regulation is performed by a hormone called insulin. Diabetes occurs when this system of glucose regulation breaks down. There are two types of diabetes helpfully called type 1 and type 2. In type I the problem is that the insulin producing areas degenerate and there is not enough of the hormone produced. In type 2 there is plenty of insulin but the tissues do not respond to the insulin as they should. Either way the normal regulation of glucose into the tissues malfunctions.  Over time this damages the blood vessels within all tissues and results in detrimental effects throughout the body, including the eye. People with type 1 diabetes tend to be younger and require regular insulin injections. Those with type 2 tend to be older, overweight and are usually treated with diet or tablets. Because as we get older many of us put on weight, type 2 diabetes is on the increase

The retina is described in the section on retinal vein occlusion. Basically it is the light sensitive membrane at the back of the eye. The central part of the retina (called the macula) is responsible the most sensitive part of our vision. Any damage here disproportionately affects how well we see. The retina requires a very large blood supply and so has many blood vessels. Diabetes damages blood vessels making the retina prone to damage from diabetes.

The longer someone has been diabetic, the more likely it is that they will develop retinal problems (diabetic retinopathy). Poor diabetic control vastly increases the risk of retinal damage. Untreated high blood pressure, smoking and high cholesterol also increase the risk of retinal damage.

What is diabetic retinopathy?

In simple terms, diabetic retinopathy is put into three categories:

1: Background retinopathy

Background RetinopathyThis is where there are mild changes in the blood vessels in the retina. Most people who have been diabetic long enough will develop these changes. Generally it is nothing to worry about provided the diabetes is well controlled along with any high blood pressure and that the eyes are regularly monitored.

 2: Proliferative retinopathy

Abnormal Blood VesselsThis tends to occur more in those with type1 diabetes, especially those whose diabetes is poorly controlled. The tiny blood vessels (capillaries) of the retina start to close and the retina becomes starved of nutrients and oxygen. This is called ischaemia of the retina. As the situation worsens changes occur in the retina that can be seen. This stage is called pre-proliferative retinopathy. If this is allowed to continue the retina produces chemicals that stimulate the production of new blood vessels. This is what we call proliferative retinopathy. This may seem a good thing but unfortunately these vessels are not healthy and they can suddenly bleed. A sudden loss of vision due to bleeding in the eye cavity may be the first indication to a diabetic person that there is a problem. Usually the blood clears from the eye. However these sudden bleeds keep recurring and scar tissue starts to form within the eye cavity. This scar tissue eventually contracts and pulls off the retina from the back of the eye resulting in blindness.

Diabetic Macula Oedema3: Diabetic macular oedema

This tends to be the problem type 2 diabetics suffer from. The capillaries in the very sensitive central retina (macula) close down and this results in fluid accumulating in the macula. If enough fluid collects in the macula the vision starts to deteriorate.

How is diabetic retinopathy treated?

The best thing is to prevent the problems occurring by maintaining good diabetic control and reducing all the other risk factors such as high blood pressure, weight and smoking. All GP surgeries offer appropriate monitoring for diabetics. On top of this all diabetic patients should have their eyes checked at least once a year.
These eye checks are very important because there are often no symptoms even when severe diabetic eye disease is present.

In the UK all diabetic patients are offered screening for diabetic retinopathy. It varies, but this usually takes the form of an annual photograph of the eyes. If any problems are picked up that person is referred into the diabetic eye service for more detailed monitoring or treatment.

Background retinopathy does not need treating. If someone is found to have pre-proliferative retinopathy their eyes will be closely monitored as well as having their diabetes in general reviewed.

Retinal Laser TreatmentProliferative retinopathy is treated with laser. Here, gentle laser burns are applied to the peripheral retina. This reduces the production of the abnormal vessel inducing chemicals in the eye and the abnormal vessels usually shrink away. It is not a painful procedure and takes about 15-20 minutes. Often several treatments are required. The main disadvantage of the treatment is that it can affect the peripheral field of vision especially in the dark. In severe cases this can affect some people’s ability to drive though this is rare.

Laser BurnsIt is very important that proliferative retinopathy is treated because if left alone it is highly likely to cause blindness.

Diabetic macular oedema (DMO) is treated by laser in the first instance. Here gentle burns are applied to the centre of the retina (macula). More than one treatment may be required. There is a risk of damaging the very sensitive macula with the laser, but the risk to vision of leaving DMO alone are much higher.

Laser BurnsLaser treatment does not always work for DMO. In these cases drugs can be injected into the eye to help clear the oedema. Often the drug injections are given if the laser fails to work but sometimes the drugs are used instead of laser. Nowadays a combination of drug injection and laser may be used.


General eye problems

Adult Squint
Presbyopia and normal ageing of the eye
Cataract FAQ's
Refractive surgery of the lens and correction of presbyopia
Dry eye
Retinal Vein Occlusion


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 Roger Holden Eye Surgeon
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