Alice Goodman

November 26, 2013

NEW ORLEANS — Living in cities with high levels of pollution increases the risk for dry eye syndrome — up to 3- to 4-fold for those living in the greater Chicago and New York areas — compared with living in areas with low pollution levels, according to a new study.

"We know that air pollution causes health problems, but there is a knowledge gap about its effect on eyes," said lead investigator Anat Galor, MD, from the Miami Veterans Administration Medical Center and Bascom Palmer Eye Institute in Florida. "Our study links air pollution with dry eye syndrome, which is an epidemic that causes human suffering. These data are yet another reason to lobby for tighter controls on air pollution."

Dr. Galor presented the study results here at the American Academy of Ophthalmology 2013 Annual Meeting.

One in 6 Americans suffers from dry eye syndrome, said Dr. Galor, which in some cases can affect the ability to read and watch television.

The retrospective study involved about 3 million patients attending a Veterans Affairs eye clinic in the United States. The 606,708 patients with a diagnosis of dry eye syndrome were compared with control subjects.

Dr. Galor teamed up with Naresh Kumar, PhD, an environmental epidemiologist at the University of Miami, to merge data from a national database on environmental pollution exposure with data on dry eye syndrome.

The researchers plotted these data on maps of the continental United States, and found that cases of dry eye syndrome clustered in urban areas of the country with high levels of pollution.

Dirty Air and Atmospheric Pressure

Air pollution, measured by aerosol optical depth, and atmospheric pressure emerged as the strongest risk predictors of dry eye syndrome. The risk for dry eye syndrome was highest in those exposed to high levels of aerosol optical depth (incident risk ratio [IRR], 1.12) and high atmospheric pressure (IRR, 1.13). Higher humidity decreased the risk for dry eye syndrome (IRR, 0.927).

Dry eye syndrome is typically treated with artificial tears, and it is estimated that these products account for $800 million annually, Dr. Galor told Medscape Medical News.

"Simple efforts in the home, such as maintaining humidity indoors and using a high-quality air filter, should be considered part of the overall management of dry eye syndrome," she said.

Dr. Galor and her team will continue to study this issue and will look at the effect of internal and external environments on dry eyes.

"It would be important to know if manipulating the environment matters," she noted. If so, it could have a tremendous economic impact.

"Dry eye syndrome is an under-recognized problem that causes day-to-day suffering," said Kavitha Sivaraman, MD, from the Illinois Eye and Ear Infirmary in Chicago. "Identifying factors that increase the risk for dry eye syndrome is a first step toward eliminating these factors using a systematic approach," she told Medscape Medical News.

"This study lends credence to the importance of reducing emissions and other environmental pollutants that contribute to dry eye syndrome and many other health problems, including asthma," Dr. Sivaraman noted.

This study was funded by a VA Career Development Award and an unrestricted grant from Research to Prevent Blindness. Dr. Galor and Dr. Sivaraman have disclosed no relevant financial relationships.

American Academy of Ophthalmology 2013 Annual Meeting. Presented November 17, 2013.


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