Statins Are Found to Help Prevent Cataracts
Cholesterol-lowering statin drugs can reduce the incidence of the most common type of cataract by 45%, according to a five-year study of nearly 1,300 people.
The findings surprised researchers because several potential cholesterol-lowering drugs never made it to market after studies showed they caused cloudiness and other eye problems.
The current study, published today in the Journal of the American Medical Assn., was actually conducted to see if approved statin drugs might have similar, but previously unobserved, side effects.
The study’s findings could have significant medical and financial consequences because more than half of Americans develop cataracts by age 80 and an estimated 1.4 million cataract surgeries are performed each year in this country.
No one is recommending that patients take statins specifically to reduce the risk of cataracts, but the drugs are so widely used that a spillover protective effect is likely.
“It’s an interesting observation and we’re very excited about it, but the findings need to be reviewed again and again in a variety of settings before we can really begin to accept them,” said lead author Dr. Barbara E. K. Klein, an ophthalmologist at the University of Wisconsin School of Medicine and Public Health.
Epidemiologist Natalie Kurinij of the National Eye Institute, which was the primary sponsor of the study, agreed, noting that the study had little information about the duration of use and the dosages involved.
Previous studies have found that statins, which provide a powerful protective effect against heart disease and stroke because of their cholesterol-lowering ability, also protect against glaucoma, macular degeneration and several other medical problems.
In the new study, their effect is thought to result from their ability to destroy oxidants, which can damage a variety of tissues.
Stress-induced accumulation of oxidants has been shown to increase cataract risk. Other antioxidant medications reduce risk, but not to the same degree as statins.
The subjects of the study were part of a larger group of 5,924 residents of Beaver Dam, Wis., whose visual health has been monitored since 1987.
The current study group of 1,299 people had no cataracts in either eye when they were examined between 1998 and 2000. All were considered to be at increased risk of developing cataracts because of their age.
Over the course of five years, 210 people developed nuclear cataracts, in which the central portion of the eye clouds over. This type produces the greatest visual impairment because it impinges on straight-ahead vision.
Overall, 12.2% of the subjects who were taking statins for other purposes developed a cataract, compared to 17.2% of those who were not taking the drugs. The drugs were equally effective in subjects who were smokers or who had diabetes -- both of which are risk factors for cataracts.
Simvastatin, brand-named Zocor, was the most commonly used statin and provided the greatest benefit, the team found.
No statistically significant benefit from statins for cortical and posterior subcapsular cataracts, the other types of the disorder, were found.
