Diabetic Retinopathy

Background Information

About one person in fifty in the UK is affected by diabetes mellitus (or sugar diabetes), which means that the level of glucose in their blood is abnormal. This causes blood vessels in the body to be fragile and liable to rupture. When this occurs in the retinal blood vessels visual impairment may result; this is called diabetic retinopathy.

Diabetic retinopathy is one of the commonest causes of blindness in the UK in people between the ages of 30-65, and 12% of people who are registered blind and partially sighted each year have diabetic eye disease. At any one time up to 10% of people with diabetes will have retinopathy requiring medical follow up or treatment.

Diabetes can also affect other organs, and the presence and severity of retinopathy may be an indicator of increased risk of other complications of diabetes such as ischaemic heart disease, kidney disease, or diabetic neuropathy (which contributes to male impotence, and diabetic foot disease).

The blood vessels can leak and haemorrhage into the eye, which leads to visual problems in two ways. Firstly bleeding into the vitreous may restrict the passage of light through the eye, especially if large. Secondly, the spot in the retina where a blood vessel has ruptured will die and become incapable of passing visual messages onwards. If a large number of blood vessels break in a particular area, there will be a large patch of missing vision.

A person's remaining useful vision will depend on the position of the affected areas and this varies from one diabetic to another. Damage around the centre of the retina will lead to a central defect in the vision. Generally, the sight is described as if looking at a jigsaw with pieces missing. The pattern of these missing pieces differs from person to person.

Treatment and prevention

Early Argon laser treatment can control the disease process in most patients; this requires regular monitoring by an Ophthalmic Surgeon or a specially trained Optometrist, at least on a yearly basis. If left too late, irreversible damage to sight may result. It is most important for people with this condition to be asked individually about their needs.

Tight control of diabetes can reduce the risk of retinopathy by 60% in type I (insulin dependent) and 40% in type II (non-insulin dependent) diabetes, and will also reduce the risk of other diabetic complications.

Although the majority of people with diabetes who have had diabetes for long enough will have some degree of retinopathy, eye checks will enable early diagnosis and early treatment. When people first develop diabetic retinopathy they have no symptoms, but, if diagnosed at this early stage, it is a treatable condition, which is why it is important for diabetics to have regular eye tests.

Diabetic retinopathy is initially treated with lasers, a procedure known as photocoagulation. In this procedure a laser beam (high-energy light beam) is applied in small bursts onto the damaged retina. This treatment is designed to maintain vision, not improve it, and is highly effective in most patients. Blindness is prevented in at least one eye of 80-90% of cases.

There are 2 laser techniques according to the type of retinopathy:

  • Maculopathy requires laser treatment around the macula at the centre of the retina to seal the leaking blood vessels.

With proliferative retinopathy, extensive laser treatment to the starved retina is undertaken. The new vessels then shrink and this reduces the long-term chance of haemorrhage, retinal detachment and severe visual loss.

Surgery

In some patients where there has been recurrent bleeding and the vitreous is clouded with blood or a retinal detachment is present, a vitrectomy operation may be necessary.

This is the removal of the vitreous (the jelly like substance which fills the eye) with the help of delicate instruments and an operating microscope. The vitreous is replaced with a clear substance, usually a form of saline, air, gas or silicone fluid. Very fine stitches are used to close the wound and these do not need removal.

Good diabetic control

Good diabetic control, especially if instituted early in the course of disease, slows down the rate of the progression of complications, though is unlikely to reverse existing retinopathy.

  • Take control of your diabetes: monitor your own blood sugars and find out from your GP what your 3 month control is like (HBA1c). Aim to reduce your HBA1c level as much as possible without running into the risk of hypoglycaemic attacks
  • Control your diet
  • Avoid becoming overweight (which is likely to increase your resistance to the effect of the body's own, or injected insulin, and worsen your diabetic control)
  • Take regular exercise (you should discuss this with your physician if you have a pre-existing heart condition)
  • Avoid smoking (smoking increases the risk of cardiovascular complications such as heart attack, stroke, and loss of limb through ischemia even more than in people without diabetes)
  • Avoid alcohol (which upsets your body's metabolism)
  • Always take your diabetic treatment. NOT taking treatment is harmful.

Disclaimer of Medical Liability

Whilst we have taken great care to gather correct information and to keep it current, we cannot guarantee its accuracy and completeness.

The information provided should never be considered a substitute for professional health care by a qualified doctor or other health care professional, which will be tailored to the patient's individual circumstances. Henshaws cannot take responsibility if you rely on this information alone.