Visual Impairment on the Rise in the U.S.
Researchers have noticed what appears to be a correlated rise in diabetes and nonrefractive visual impairment.
-- by Nina Lincoff
Diabetes mellitus, or the group of metabolic diseases that causes a disregulation of the hormone insulin and absorption of glucose, or fuel, is on the rise in the United States. And for those suffering from diabetes, there may be more to worry about than just blood sugar.In addition to its links to other chronic health problems, diabetes mellitus may also be connected to the increase of nonrefractive visual impairments amongst Americans, finds a new study published in the Journal of the American Medical Association.
Visual impairment, or having less than 20/40 vision, is a condition that affects more than 14 million people in the United States, and has a variety of causes, including cataracts, glaucoma, diabetic retinopathy, macular degeneration, and other retinal disorders. “Visual impairment of 20/40 is a threshold at which many states do not allow [an] unrestricted driver's license, and the threshold at which eye doctors will perform cataract surgery,” says study author Dr. Fang Ko, M.D. Nonrefractive visual impairment means that the impairment can’t simply be fixed by glasses.
The Expert TakeAlthough diabetes is known mostly for the metabolic problems it brings about, it also has adverse effects on other parts of the body. Visual impairment is, for instance, a common condition in people with diabetes.
“Diabetes affects many parts of the body, including the kidneys, heart, and brain," explains Ko, who points out that the rise of visual impairment "raises a red flag that there may be other systemic health problems potentially on the rise.” With diabetes sitting as the number seven leading cause of death in the United States according to the Centers for Disease Control and Prevention, the disease is clearly affecting more and more people.
“These are people who need surgery, medication, or may have impairment that cannot be fixed at all,” says Ko. An important finding of this study is “that this sort of visual impairment has increased 20 percent in 7 years.” When researchers look at different factors that could be affecting visual impairment—such as smoking, poverty, poor ophthalmic medical insurance, blood pressure, etc.—they realized that “diabetes was the only associated factor which has risen during the same time period.”
What is particularly worrisome, says Ko, is that this kind of visual impairment is increasingly “affecting those 20-39 years old. Typically, we think of diabetes-related eye disease as a chronic illness that affects older Americans... For someone to have diabetes of sufficient severity and duration to cause visual impairment in their 20s and 30s is surprising.”
Source and Method
Between 1999 and 2002, and 2005 and 2008, over 9,000 and 10,000 participants were enrolled, respectively, in the National Health and Nutrition Examination Survey. Participants were 20 years or older and underwent physical examinations and tests, and also answered questionnaires. Researchers correlated a risk of health risk factors and nonrefractive visual impairment, and compared the results from both three-year time periods to asses change.
With diabetes-related visual impairment on the rise, an open dialogue between patients and physicians is imperative, now more than ever.
“Communication between specialists is absolutely important,” says Ko. “When a primary care physician diagnoses diabetes, they should be in contact with an ophthalmologist to arrange an eye exam,” and that conversation should continue cyclically, with specialists and primary care physicians working for holistic diabetes control.
It’s paramount that those living with type 2 diabetes receive annual eye exams. “If caught early, they can potentially receive sight-saving treatment,” says Ko.
In a 2009 study in Diabetic Medicine, researchers from the United Kingdom examined the prevalence of type 2 diabetes (nonhereditary) and associated health problems amongst the elderly.