Diabetes is an increasingly common disease in the UK. The underlying problem is caused by reduced insulin levels in the body or a reduced sensitivity to insulin causing high blood glucose levels to build up. High, uncontrolled blood glucose can have damaging effects on many parts of the body including the eye. In the early stages this does not have any effect on the sight so all diabetics are recommended to have regular eye checks by their optician. If eye problems develop you may be referred to a retinal specialist to assess this further and consider treatment if appropriate.
What types of eye problems are caused by diabetes?
The main effect of diabetes is on the retina, the light sensitive layer lining the inside of the eye. Two types of effects occur diabetic retinopathy and diabetic maculopathy.
Diabetic retinopathy starts as small haemorrhages visible in the eye and spots of leakage from the circulation. The small blood vessels in the eye may become dilated or closed off reducing the circulation to the retina. If there are large areas of the retina to which circulation has been reduced the eye makes new blood vessels to compensate. However, these new vessels are not beneficial and carry of risk of bleeding which does affect the vision. Progressive enlargement of these vessels can also lead to scarring and detachment of the retina which can also damage the sight.
Diabetic maculopathy is a type of diabetic eye disease specifically affecting the macula, the very central part of the retina which is responsible for fine detailed vision, colour perception and enables us to read. Diabetes can cause the small blood vessels which supply to macula to become abnormal and close of reducing the circulation to this crucial part of the eye. The changes in the blood vessels lead to leakage of fluid and fatty material into the retina. Fluid build-up in the macula and reduced circulation can cause progressive, irreversible damage to the vision.
How can the risk of diabetic eye disease be reduced?
Diabetic retinopathy and maculopathy can be prevented, slowed down or even reversed with good control of the factors that can potentially make it worse. Improving these factors also improves the likelihood of getting benefit from treatment. These are:
- Blood glucose control. Average blood glucose is regularly assessed in your diabetic clinic. The closer this is to normal levels the better. Discuss how you are doing at your next diabetic clinic appointment.
- Blood pressure. Diabetics commonly have high blood pressure as well so this should be regularly checked. Poor blood pressure control can worsen all types of retinopathy especially diabetic maculopathy.
- Smoking. Smoking can accelerate the worsening of diabetic eye disease and reduce the chances of improvement even if other factors are controlled and treatment is being given. Diabetic in particular are recommended to stop smoking.
- Blood cholesterol. A low fat diet is recommended for health generally. In diabetics it is important to keep cholesterol levels controlled because high levels can worsen diabetic eye disease. If you are diabetic your doctor may recommend you take cholesterol lowering tablets even if your blood levels are not too high.
- Pregnancy. The hormonal changes during pregnancy can accelerate diabetic eye disease. It is important if you diabetic to have regular checkup during pregnancy.
What are the treatments for diabetic retinopathy?
If diabetic retinopathy progresses to the form in which the eye makes new blood vessels laser treatment is required. This can help the abnormal blood vessels to shrink away. In some cases eye injection treatments such as Lucentis, Avastin or Eylea may be required. In more severe cases in which there is bleeding in the eye or detachment of the retina, surgery may be required.
What are the treatments for diabetic maculopathy?
Diabetic maculopathy in the early stages may not be sight threatening so treatment may not be required. You may be advised to work with the diabetic clinic in ensuring all the potential risk factors are controlled as best as possible. If the disease involves the central parts of the macula and is a risk to the vision or is already affecting the vision one of the following treatments may be recommended.
- Laser treatment. Laser applied to specific parts of the retina can be beneficial at reducing the process of leakage and helping a macula in which there is fluid to dry up. It is usually the most appropriate treatment when the fluid has not yet affected the central parts of the vision. When there is visual impairment due to fluid affecting the central parts of the vision, laser treatment can have a stabilising effect but does not usually improve vision in the majority of cases. There is therefore an increasing role for new injectable eye treatments for such disease.
- Anti-VEGF injections. When an eye is affected by diabetic maculopathy there are increased levels in the eye of a chemical called vascular endothelial growth factor (VEGF). This chemical contributes to the process of leakage and bleeding into the retina. New injectable drugs which counteract this rise in VEGF are called Lucentis, Avastin and Eylea. Many studies have shown the benefits of regular anti-VEGF injection treatment for patients with diabetic maculopathy. This treatment approach appears to be superior to laser treatment and there is more of a chance of getting actual improvement in vision.
- Steroid injections. In severe cases injection of steroid into the eye may also be beneficial. This may be in a standard liquid form or a slow release implant such as Ozurdex or recently released Fluocinolone implant. Steroids have a slightly higher rate of side effects compared to anti-VEGF injections so they tend to be reserved for more severe cases.
The management of diabetic maculopathy is complex and has to be tailored to the individual case. Depending on the way it is specifically affecting your eye you may require one or more of the above treatments in combination. This would be discussed with you after a full examination and relevant diagnostic scans and photographs of the eyes. Whereas in the past treatment options and results from them were limited, there is more of a hope now of treatment which can have a positive effect and offer improvement.
If you have been affected by any of the symptoms mentioned above, please don't hesitate to give us a call.
We have a team of experts on stand-by who are ready to take your call at our Manchester (0161 907 2685) Clinic or our Blackpool (01253 308 031) Clinic.