Dry eye linked to air pollution coupled with weather conditions NEW ORLEANS, Nov. 17 (UPI) -- Residents of major cities such as Chicago or New York with high levels of air pollution have an increased risk of dry eye syndrome, U.S. researchers say. Dr. Anat Galor of the Miami Veterans Affairs Medical Center, assistant professor of clinical ophthalmology at the Bascom Palmer Eye Institute, said dry eye syndrome, a deficiency in tear production, is a prevalent condition affecting up to 4 million Americans age 50 and older and whose manifestations negatively affect physical and mental functioning. The symptoms of dry eye syndrome can be very detrimental to patients and severely affect the quality of one's life, as well as result in loss of productivity due to interruption of daily activities like reading and using computer screens, Galor, the lead researcher, said. This is the first study of a large patient population covering the entire continental United States to link dry eye syndrome treatment location to atmospheric conditions -- in particular, air pollution coupled with weather conditions, Galor said. Using data from the National Veterans Administrative database, the National Climatic Data Center and National Aeronautics and Space Administration, the researchers examined the health records of 606,708 U.S. veterans who received dry eye syndrome treatment in one of 394 VA eye clinics within the continental United States from July 2006 to July 2011. Those living in areas with high levels of air pollution had the highest magnitude of increased risk for dry eye syndrome, at an incidence rate ratio of 1.4. Most metropolitan areas, including New York City, Chicago, Los Angeles and Miami, showed relatively high prevalence of dry eye syndrome -- ranging from 17 percent to 21 percent -- and high levels of air pollution. The findings were presented at the 117th annual meeting of the American Academy of Ophthalmology in New Orleans.