Dubai, UAE: Diabetes mellitus is one of the leading causes of irreversible blindness world wide. It is the most common cause of blindness in people younger than 65 years of age, said Dr Rajeev Kumar, Specialist Ophthalmologist, Zulekha Hospital, Sharjah.
Diabetes may cause a reversible, temporary blurring of the vision but it can also cause a severe, permanent loss of vision. It increases the risk of developing cataracts and glaucoma. Severe diabetic eye disease most commonly develops in people who have had diabetes mellitus for many years and who have had little or poor control of their blood sugars over a period of time. Diabetes may also result in heart disease, stroke, kidney failure, and circulatory abnormalities of the legs.
The primary part of the eye affected is the retina. “The retina can be thought of as the film in a camera. If the film in a camera is faulty, the resulting picture will be blurry. In a similar manner, if the retina of the eye is swollen, wrinkled, or otherwise structurally damaged, the vision in that eye will be blurry,” he said.
Depending on the type, location, and extent of damage in the retina, the change in vision will range from minimal to severe and be temporary or permanent. In people with diabetes mellitus, changes in the walls of the small blood vessels in the retina are caused by blood sugar abnormalities.
These small blood vessels may begin to ‘balloon’ as well as leak fluid (called edema) and blood (called dot and blot hemorrhages) into the retina. This process is called background diabetic retinopathy or nonproliferative diabetic retinopathy. If fluid accumulates in the central part of the retina (called the macula) and causes swelling there, the process is called diabetic macular edema.
As a response to decreased oxygen delivery to the retina, new blood vessels may begin to grow. Although new blood vessels may sound like a good thing, considering that the old blood vessels are damaged, the new blood vessels are actually more harmful than beneficial. The new blood vessels are extremely leaky and fragile, potentially leading to bleeding inside the eye and usually resulting in severe vision loss. If not treated appropriately, this vision loss may be permanent. If the new blood vessels are extensive, they may cause scarring inside the eye, resulting in tractional retinal detachments, which is another cause of permanent vision loss. In cases of severe proliferative diabetic retinopathy, new blood vessels may grow on the surface of the iris, causing neovascular glaucoma, a particularly severe form of glaucoma.
If the patient controls their weight, eats a proper diabetic diet, exercises regularly, monitors blood sugars, and takes the prescribed diabetic medications, the chances of developing serious eye problems decrease dramatically.
For diabetic retinopathy, surgical treatment (for example, laser treatment) is the treatment of choice. Injections or newer anti-vascular-proliferative medications in the area around the eye may be used.
© Khaleej TimesFeb 2013