Good nutrition, exercise, adequate zinc intake, and not smoking are thought to prevent or slow the progression of macular degeneration, and many people with early macular degeneration continue to see well enough to lead a normal life. There are also some laser treatments, as well as a type of injectable medicine ranibizumab (brand name Lucentis), for the most severe kind of macular degeneration.
If vision loss reaches the level at which a person can no longer read with ordinary glasses, optical magnification systems and closed-circuit TV systems (although they are bulky and rather expensive) provide even greater magnification. When print is magnified, you only see a small area of what you are reading at any one time. This can take a little getting used to, but it is far better than being unable to read.
The main reason people with diabetes are encouraged to have regular eye exams is to look for changes in the blood vessels of the retina that indicate diabetic retinopathy. Diabetic retinopathy develops as prolonged exposure to high blood glucose weakens the walls of the blood vessels in the eyes. The longer a person has had diabetes and the greater his exposure to high blood glucose, the greater his risk of having this condition.
The earliest signs of diabetic retinopathy are little red or white spots on the retina that can only be seen by an eye doctor. These spots are microaneurysms, tiny pouches of blood that have bulged through the damaged blood vessel walls and can leak blood, fat, and fluid into the retinal tissues. These early changes in the blood vessels are called background, or nonproliferative, retinopathy. Leaking in the retina from background retinopathy can cause some blurring of vision, but it does not usually require immediate treatment.
If diabetic retinopathy causes damage near the macula, however, fluid leaking into the macula makes it swell like a mosquito bite. This swelling, called macular edema, is the most common cause of visual impairment in diabetic retinopathy. (Reduced blood supply to the macula is a less common occurrence. As yet, it is not treatable.)
The earliest changes of retinopathy can even be temporary: here today and gone in six months. If damage continues, though, the risk increases that new, abnormal blood vessels will start to sprout in retina and poke through into the vitreous. This important change is called going from background retinopathy to proliferative retinopathy.
The new blood vessels apparently proliferate in an attempt to increase blood and oxygen supply to the damaged retina. They are so fragile, though, that they rupture at a cough, a sneeze, or even during sleep. Blood pours into the retina, blocking vision suddenly. When the bleeding stops, scar tissue forms, tugging at the retina and adding the potential for a retinal detachment.
Untreated proliferative retinopathy usually leads to blindness. Not long ago, diabetic retinopathy was just about the most discouraging condition that ophthalmologists had to deal with. Fortunately, in recent years, a number of large national studies have proven that laser treatment of the retina can help control proliferative diabetic retinopathy and significantly prolong useful vision.
Ironically, laser treatment works by producing scarring on the affected retina. The treated part of the retina will no longer see, but the laser treatment halts the growth of new blood vessels and preserves vision in the most important part of the retina, the macula. Laser treatment for diabetic retinopathy is a tremendous tool that has expanded the ability to treat diabetic eye problems.
A surgical procedure called a vitrectomy, in which blood, scar tissue, and vitreous are removed from the eye and replaced with a saline solution, is also a relatively new, successful treatment for retinopathy that affects the vitreous.
Looking out for your eyes
Currently, the American Diabetes Association recommends that adults and children 10 and older with Type 1 diabetes have an initial dilated and comprehensive eye examination within five years after they are diagnosed with diabetes. People with Type 2 diabetes are advised to have a dilated and comprehensive exam shortly after the diagnosis of diabetes. After the initial exam, everyone with diabetes is encouraged to have a yearly exam.