DIABETIC EYE DISEASE

An optometrist reported how a routine eye examination on a 49-year old patient revealed the first clue that the patient may have diabetes. "As soon as I noticed blood and leaking fluids seeping out of fragile vessels in the retinas, I suspected they may be symptoms of diabetes." Sure enough, a medical examination confirmed that the patient did indeed have diabetes. With control of the diabetes in its early stages, the retinal bleeding stopped and the patient's vision began to improve.

This is not an uncommon scenario as the first signs of diabetes are very often detected in the eyes.

Diabetes is one of the fastest growing diseases in South Africa, and yet of the 3.5 million South Africans who have it, 1.5 million are unaware of it. Thousands of diabetics eventually lose their sight to diabetic retinopathy. Don't be a statistic! Early detection leads to timely management and often to reversing or at least slowing down the progression of diabetic eye disease. November 14th is World Diabetic Day. Protect your health and your vision - take advantage of the numerous screenings and awareness campaigns running in November.

THE LINK BETWEEN EYE DISEASE AND DIABETES

Diabetes is a chronic group of metabolic diseases in which the body cannot control the sugar levels in the blood, due to insufficient or ineffective insulin. High blood sugar levels cause tiny leaks in the blood vessels of the retina. Blood and fluid seep into the retina, which then becomes wet and swollen, affecting vision. A second problem is that the blood vessels may close, depriving the retina of essential nutrition, so that it is unable to function adequately.

The three major eye problems that people with diabetes may develop are cataracts, glaucoma and retinopathy.

DIABETES AND CATARACTS

A cataract is a clouding or fogging of the normally clear lens of the eye. The function of the lens is to focus light that enters the eye onto the retina at the back of the eye. In a person with cataracts, vision is blurred and there is increased sensitivity to light and glare. While cataracts are common, people with diabetes develop these eye problems at an earlier age than most, and the condition progresses more rapidly than in people without diabetes.

GLAUCOMA AND DIABETES

When fluid inside the eye does not drain properly, it can lead to excess pressure inside the eye. The increase in pressure can damage nerves and blood vessels in the eye, causing changes in vision. People with diabetes are twice as likely to develop glaucoma as non-diabetics.

In open-angle glaucoma, the most common form of glaucoma, there may be no symptoms until the disease is advanced and there is significant vision loss. In its less common form, symptoms can include headaches, pain in the eyes, blurred vision, halos around lights, and loss of vision.Treatment of open-angle glaucoma requires lowering the eye's pressure by increasing the drainage or decreasing the production of fluid. It may include eye drops, laser procedures, medication or sometimes surgery.

People with diabetes are more likely to have an uncommon type of glaucoma, called neovascular glaucoma, in which new blood vessels grow on the iris, the coloured part of the eye. These blood vessels block the normal flow of fluid out of the eye, raising the eye pressure. It is difficult to treat.

DIABETIC RETINOPATHY

Retinopathy is a general term describing damage to the retina. Diabetic retinopathy, which is due to the damage of small blood vessels, is one of the vascular (blood-vessel related) complications of diabetes. The duration of diabetes is the single most important risk for developing retinopathy; the longer you have diabetes, the greater the risk of this serious eye problem. If retinopathy is not found early or is not treated, it can lead to blindness.

People with type 1 diabetes rarely develop retinopathy before puberty. In adults with type 1 diabetes, it is rare to see retinopathy before five years' duration of diabetes. People with type 2 diabetes usually have signs of eye problems when diabetes is diagnosed. In this case, control of blood sugar, blood pressure, and blood cholesterol with diabetes have an important role in slowing the progression of retinopathy and other eye problems.

There are various types of diabetic retinopathy:

Background retinopathy - Sometimes the blood vessel damage exists, but there is no vision problem. It is important to carefully manage the diabetes at this stage to prevent background retinopathy from progressing to more serious eye disease.

Maculopathy - In maculopathy, there is damage in the macula, which is critical to vision.This type of eye problem can significantly reduce vision.

Proliferative retinopathy - With this type of retinopathy, abnormal new blood vessels start to grow in the back of the eye, due to the increasing lack of oxygen and nutrients being carried to the retina because of the vascular disease.Vessels in the eye are thinned and occluded and they start to remodel. It is important to address the risks factors that can worsen the occluded vessels. Giving up smoking, blood pressure control, cholesterol management, and blood sugar control can stop or slow down the progression of new vessels from forming into the orbit of the eye. These are fragile vessels that can bleed and eventually cause a clot to form in the orbit, which scars and may cause detachment of the retina. This eventually leads to irreversible vision loss.

Symptoms of diabetic retinopathy can include blurred or double vision, flashing lights, a cloud or streaks of red in the field of vision, floating spots in one or both eyes, blind spots in the field of vision, fluctuating vision in response to changes in blood glucose levels, decreased depth perception, and blurred central vision. If you have diabetes, and experience any of these symptoms, make an appointment to visit your optometrist.

PREVENTION OF DIABETIC EYE PROBLEMS

Everyone should have regular eye examinations, but annual eye exams are particularly important for people with diabetes. A thorough eye examination can help identify a problem early on when it can be more easily treated and prevent further vision loss.

If you are considering pregnancy and have a history of diabetes, you should have an eye examination prior to, and be monitored during pregnancy. Discuss this with your optometrist.

Controlling your blood sugar and blood pressure will help prevent eye problems if you have diabetes.

Lifestyle can be a factor in the development of diabetes, so eat a healthy balanced diet, exercise regularly, and give up smoking.

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