Cataracts are a common cause of vision loss in older adults.
In 2004, the Eye Diseases Prevalence Research Group (EDPRG), estimated that 20.5 million Americans (17.2 percent) over age 40 had a cataract in either eye, and 6.1 million (5.1 percent) already had a cataract removed. And according to the National Eye Institute (NEI), by age 80, more than half of all Americans either have a cataract or have had cataract surgery.
But, besides advancing age, are there other risk factors associated with the development of cataracts?
A large study of 3,721 adults in Australia found the following additional risk factors for cataracts:
- Women are more likely than men to develop cortical cataracts. (This was also true in the American study by EDPRG, which found that women are almost 40 percent more likely than men to develop cataracts.)
- Working as a laborer (compared to having a white-collar occupation) and myopia also are risk factors associated with cortical cataracts.
- Cigarette smoking and a history or arthritis are associated with the development of nuclear cataracts.
- Diabetes and taking calcium channel blockers (medications commonly used to treat high blood pressure) for more than five years are risk factors associated with posterior subcapsular cataracts.
It is likely that in the United States, there will be an increase in diabetes-related cataracts in the future. According to the Centers for Disease Control and Prevention, 34 percent of Americans over age 20 are obese, and obesity is a primary risk factor for Type 2 diabetes. Currently, 24 million Americans (8 percent) have known diabetes, and an estimated 57 million (19 percent) have “pre-diabetes,” meaning they have blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes.
Some researchers believe that by the year 2050, the number of diabetes-related cataracts will increase by over 200 percent. Also, the number of Americans with diabetic retinopathy (another vision-threatening complication of diabetes) is expected to increase from 1.2 million to 3.4 million over the same period.
The take-home message: If you want to lower your risk for cataracts, two steps you can take are to avoid or quit smoking and, if you are overweight or have pre-diabetes, to consult with your doctor and begin a diet and exercise program to lower your risk of diabetes.
Sources:
- Prevalence of cataract and pseudophakia/aphakia among adults in the United States. Archives of Ophthalmology. April 2004.
- Development of cataract and associated risk factors: The Visual Impairment Project. Archives of Ophthalmology. January 2006.
- Diabetes and obesity: A challenge for every ophthalmologist. Archives of Ophthalmology. March 2009.