Over two million Canadians are afflicted by diabetes and the incidence appears to be on the rise, according to the Canadian Diabetes Association. Damage to the eye caused by diabetes now is the most common cause of blindness in people under 65 and the most common cause of new blindness in North America.
Diabetes is a condition in which the level of glucose (sugar) in the blood goes abnormally high because the body no longer produces adequate insulin, or it has become insensitive to the normal glucose-regulating action of insulin. High blood glucose can cause the lens inside the eye to swell and change its shape, which leads to blurry vision and a change in eyeglass prescription.
Long-term diabetes, especially when poorly controlled, can take its toll on the eyes in serious ways. People with diabetes are more likely to develop cataracts at a younger age, and are also more prone to the development of glaucoma. However, the most common threat to diabetics arises in the retina, which is the thin, delicate membrane of blood vessels and nerve endings that line the back of the eye. The retina contains a dense network of tiny blood vessels, and when diabetes has been present for several years, the walls of these blood vessels may develop weak spots, which cause small haemorrhages to form within the retina. Fortunately, these spots generally have no effect on vision, but can be easily seen when the back of the eye is examined by an eye doctor.
About one in every four or five patients with background diabetic retinopathy eventually go on to develop a more serious problem known as proliferative retinopathy. In this condition, the small blood vessels that supply the retina become inefficient at providing adequate circulation, which causes some areas of the retina to degenerate due to a lack of oxygen. Scar tissue can begin to form within the eye, which may lead to ruptures and detachments of the retina as well as a host of other secondary problems. The bad news is that any of these complications can rapidly lead to a devastating loss of vision which may or may not be permanent once it develops.
Luckily, highly precise and sophisticated laser treatments have been particularly beneficial to those with diabetic eye disease. Of course, like many medical procedures, treatment is most promising if it is undertaken early.
Most doctors advise diabetic patients to have their eyes thoroughly examined at least once a year. This is clearly recognized by the Ontario Health Insurance Plan (OHIP) as it will cover the cost of yearly routine eye exams for patients of all ages that have been diagnosed with diabetes.
Dr. Ken Hadley, a lecturer at the University of Waterloo’s School of Optometry & Vision Science, is particularly dedicated to encouraging his patients to monitor their diabetic conditions. He has been an insulin-dependent type 1 diabetic for 43 years now, and developed significant retinopathy 15 years ago. On a personal level, he is convinced that close monitoring and optimal blood glucose control were instrumental in bringing his retinopathy under control.
I often tell patients of my own experience if I have a sense that it might inspire them to optimally manage their diabetes. A thorough examination conducted by your eye care professional on a regular basis is so easy to do, and if diabetes is a part of your health care picture, it will pay off sooner or later! says Hadley.
May is Healthy Vision Month, and we hope you will consider Hadley's advice and see an eye care professional for regular check-ups. #HealthyVisionMonth