DOCTOR'S VIEW ARCHIVE
Diabetes & Eye Disease...See No Evil
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
If you knew that something as simple as an annual visit to an eye specialist (Ophthalmologist) could help prevent you from going blind, would you keep your yearly appointment? Likewise, if you knew that controlling your blood sugar levels in diabetes could slow down the progression of eye disease, would you think twice before having a second cookie?
Diabetes (both type 1 and type 2) is complicated by eye disease (damage to the retina, called retinopathy) in over 60% of patients. The retina is the portion of the eye that detects light and its function is essential for vision. Diabetes is one of the leading causes of blindness in the United States.
In general, diabetes-related eye disease progresses in an orderly fashion, with a strong relationship to the length of time a patient has had diabetes. In type 1 diabetes, retinopathy usually doesn't develop until after the first 5 years. By the next 20 years, nearly all patients with type 1 diabetes have significant eye disease. In type 2 diabetes, up to 21% of patients already have eye involvement at the time they are diagnosed with diabetes. Diabetic retinopathy is characterized by the formation of new blood vessels in the back of the eye (neovascularization). These vessels are weak and can tear, resulting in bleeding in the back of the eye. Scarring can lead to detachment of the retina, and the condition can be complicated by central vision impairment known as macular edema (swelling of the macula).
Let's go back to the two questions asked in the first paragraph.
If you knew that something as simple as an annual visit to an Ophthalmologist could help prevent you from going blind, would you keep your yearly appointment?
Two large trials sponsored by the National Institutes of Health (the Diabetic Retinopathy Study and the Early Treatment Diabetic Retinopathy Study) have shown that laser surgery can reduce the risk of vision loss from diabetic eye disease. However, the laser treatment is not beneficial in reversing vision impairment once it has already occurred. An assessment by the eye doctor is the only way to know if laser surgery is needed. The American Diabetes Association strongly recommends that all patients with diabetes have annual eye exams.
If you knew that controlling your blood sugar levels in diabetes could slow down the progression of eye disease, would you think twice before having a second cookie?
While I ask this question tongue-in-cheek, the straight answer is that there is a definite relationship between blood sugar control and diabetic eye disease. In a landmark study (the Diabetes Control and Complications trial), two groups of patients were followed: type 1 diabetics with tight control on an intensive regimen; and type 1 diabetics with less stringent control on conventional therapy. At the end of the study, the intensive control of the blood sugar prevented the development of eye disease by 27% and reduced the progression of eye disease in those who had disease at the start of the trial by 76%! These results were echoed in patients with type 2 diabetes in the United Kingdom Prospective Diabetes Study (UKPDS).
Now that you have evidenced-based scientific proof that an annual eye exam and tight blood sugar control can help keep your sight as good as possible for as long as possible, the answers to the above questions are obvious! If you have diabetes, I hope you continue to do your part and "see no evil" for years to come.
For additional Doctor's Views written by Dr. Mathur, please visit the Doctor's Views Library.
Last Editorial Review: 7/20/2005