Diabetic Eye Disease
Diabetic eye disease is a comprehensive term used to describe a group of eye problems that people with diabetes may face as a complication of their illness. All of these diseases have the potential to cause severe vision loss or even blindness. Therefore, diabetes eye treatment is of the utmost importance.
What is Diabetes Mellitus?
Diabetes is a metabolic disease caused by either a lack of insulin or the presence of factors that oppose the action of insulin. The end result is an increase in blood glucose concentration (hyperglycaemia), which means that there is too much sugar in the blood. Diabetes is diagnosed by a blood glucose test. There are two types of diabetes:
- Insulin-dependent (Type 1) diabetes: This normally occurs due to damage to an individual’s pancreas. It mostly affects patients between ten and 20 years of age, although elderly patients can also be insulin dependent.
- Non-insulin-dependent (Type 2) diabetes: It has no known cause, although in many cases there is a strong genetic component. It is most prevalent after middle age and occurs most frequently between the ages of 50 and 70 years. It tends to occur in the overweight and elderly and is often asymptomatic.
When blood sugar is constantly or frequently high, many complications occur. Eyesight can suffer, heart attacks and other blood vessel problems can occur, and one's lifespan can be significantly shortened. When blood sugar is maintained at a normal level at all times, the complications of diabetes (including serious diabetic retinopathy) can be reduced. Controlling blood sugar is the single most important thing a person with diabetes can do to prevent the complications of diabetes and diabetic retinopathy.
Patients with diabetes should follow a diet controlled in carbohydrates and low in fat and cholesterol. Regular exercise is also very important as it helps reduce blood sugar. They should also see a general physician, internist, or endocrinologist, who has the knowledge to help people with diabetes strictly control their blood sugar.
In addition to the importance of diet and exercise, there are other factors that can affect diabetes. High blood pressure is a problem because it increases the likelihood of complications, including diabetetic eye disease. Blood pressure should be strictly controlled and kept normal. Smoking is known to be particularly bad for people with diabetes because it promotes the closure of blood vessels.
Finally, the severity of diabetic retinopathy is often related to the length of time the person has had the illness. It is unusual for someone with Type 1 diabetes to have significant diabetic retinopathy during the first ten years of the disease. After ten years, and especially after 20 years, most people with Type 1 diabetes have some retinopathy, although it may not be severe, especially if the blood sugar level has been sufficiently controlled. In people with Type 2 diabetes, the diabetic retinopathy may be discovered shortly after, or sometimes even before, the disease is diagnosed.
All people with diabetes, especially those who have had diabetes a long time, should have regular eye examinations (particularly examinations of the retina, through a dilated pupil) to be sure that diabetic retinopathy is not developing.
How is diabetes linked to eye disease?
The eye disease Diabetic Retinopathy is characterised by abnormal retinal blood vessels. Normally, the blood vessels in the retina do not leak, but with diabetes, it can develop tiny leaks, causing fluid or blood to seep into the retina. The retina then becomes wet and swollen, affecting the vision. The form of diabetic retinopathy caused by leakage of the retinal blood vessels is called Non-proliferative (or background) diabetic retinopathy, or macular swelling.
Another problem with the retinal blood vessels in the case of diabetes is that it can close. The retinal tissue, which depends on those vessels for nutrition, will no longer function properly. The areas of the retina in which the blood vessels have closed then foster the growth of abnormal new blood vessels, called Neovascularization, which causes blindness by bleeding into the vitreous cavity. It can also cause the development of scar tissue, which can pull the retina loose (this is called a traction retinal detachment). Either of these serious problems (vitreous bleeding or traction retinal detachment) can result in severe loss of vision or even blindness. The form of diabetic retinopathy caused by closure of the blood vessels leading to the development of neovascularization (proliferates) is called Proliferative diabetic retinopathy.
Laser eye treatment
Laser eye treatment can be very helpful for the treatment of diabetic retinopathy. The laser beam is a high-energy light that turns to heat when it is focused on the parts of the retina to be treated. In Non-proliferative diabetic retinopathy, the laser heat either seals the leaking blood vessels of the macula or reduces their leakage and allows the macula to dry. In Proliferative diabetic retinopathy, the laser eye treatment destroys the diseased portion of the retina to stop the growth of neovascularization (abnormal new blood vessels).
Essentially, the major purpose of laser eye treatment is to prevent further visual loss. However, laser eye treatment may not always be the best option or even viable. The decision to use laser depends mostly on the type of diabetic eye disease, its severity, and a judgment regarding how well it may respond to laser eye treatment.
Because diabetes is a condition for which there is currently no cure, the disease may continue to damage the retina. Even with laser eye surgery patients may continue to lose vision. But when laser is effective, the chances are that it can prevent further visual loss.
Avastin and Lucentis injection may be beneficial to some patients suffering from macular edema related to their diabetes.
If Dr. Krüger diagnoses diabetic retinopathy and feels that laser eye treatment might be helpful, a special test called Fluorescein Angiography may be done. To do the test, dye is injected into a vein in the patient's arm. The dye travels throughout the body, including the eyes. With a special camera and flash a series of photographs of the retina is taken as the dye passes through it. The photographs will show what types of changes have occurred in the retina. It will also provide a type of map, which Dr. Krüger will use as a guide to determine the exact location and amount of laser eye treatment necessary.
Measure your own vision in each eye separately, repeating this each day. Know how much you can see with each eye. If you notice any change in your vision, call Dr. Johann Krüger for an appointment. It is important for all people with diabetes to have a thorough retinal examination regularly, about every twelve months, even when there are no problems. Be sure to come every two months if you have Neovascularization and every three months if Background Retinopathy has been diagnosed.
Also, be sure to talk to your own medical doctor about the importance of diet and exercise and the dangers of smoking and high blood pressure. And, most of all learn to maintain the best possible control of your blood sugar. The complications of diabetes, especially diabetic retinopathy, can be reduced by long-term, strict control of blood sugar.
Dr. Johann Krüger will always be available to answer your questions and to help in every way possible. You are encouraged to call with any unusual symptom or worry. Please do not hesitate to contact us if you have any further queries with regard to diabetic eye disease and the treatment thereof.