Vision problems that can’t be corrected with eyeglasses are on the rise
among Americans age 20 and older, a new study finds. And the growing prevalence
of these problems may be partially related to increasing rates of diabetes.
Researchers reported that nonrefractive visual impairment, a vision problem
not caused by the need for eyeglasses, rose 21 percent, from 1.4 percent
between 1999 and 2002 to 1.7 percent between 2005 and 2008.
During the same time period, the number of people with diabetes has climbed from 6.5 percent in 1998
to 10.7 percent in 2007 and 11.3 percent in 2010.
Younger adults are especially at risk for vision
problems, the study reported. Among non-Hispanic whites ages 20 to 39, nonrefractive
visual impairment soared by 40 percent, climing from 0.5 percent during the
1999-2002 period to 0.7 percent during the 2005-2008 period. While the increase
may sound small, the authors of an accompanying editorial wrote that "with
about 230 million people aged 20 years and older in the U.S. population, a 0.3%
increase could potentially represent an increase of almost 700,000 individuals
with nonrefractive visual impairment over a relatively short time."
The study researchers analyzed data from the National Health and Nutrition
Examination Survey (NHANES), an ongoing survey of the health and nutritional
status of Americans. This particular survey examined information on 10,480
people ages 20 and older.
The most common causes of nonrefractive visual impairment in the U.S. are age related macular degeneration,
cataracts, diabetic retinopathy, glaucoma and other retinal disorders, the
study noted.
Diabetic retinopathy, which can affect people with Type 1 or Type diabetes,
is caused by damage to the small blood vessels in the retina, which is the
light-sensitive tissue at the back of the eye, according to the National Eye
Institute. This disorder is the leading cause of blindness in Americans 40 and
older. Diabetes can also increase the risk of cataracts and glaucoma.
Survey found that people who were older, who were living in poverty and who
had been diagnosed with diabetes 10 or more years previously had the most risk
for nonrefractive visual impairment. However, the researchers wrote,
"Among these risk factors, only the latter has increased in prevalence
during the two time periods considered."
An estimated 25.8 million children and adults in the U.S. have diabetes,
according to the American Diabetes Association. Nearly two million new cases
were diagnosed in people 20 and older in 2010.
The study findings concern serious health problems, the researchers said.
"Blindness and visual impairment are associated with increased medical
care expenditure, decreased work productivity and decreased quality-adjusted
life years," the researchers wrote. "If the current finding becomes a
persisting trend, it could result in increasing rates of disability in the U.S.
population."
