Air Pollution Poses a Threat to Your Vision

Air pollution is a mixture of natural and man-made substances in the air we breathe. How toxic it is depends on what the air pollution is made of and how much there is. Based on a recent study, protecting one’s eyes with a physical barrier may not prevent eye problems because chemicals we breathe in may make their way to our eyes through the bloodstream. Compared to many places, Lehigh Valley’s air quality is generally pretty good, but it may be bad where you live, work or while you commute to work on busy streets or highways. A study by Dr. Suh-Hang Hank Juo and his colleagues from the center for myopia and eye disease at China Medical University in Taiwan showed for the first time in a large population that exposure to two common air pollutants, nitrogen dioxide (NO2) and carbon monoxide (CO), can lead to an increased chance of developing age-related macular degeneration, which causes damage to the macula, in the center of the eye, resulting in blurry central vision and potentially total vision loss, reports Time magazine. Researchers looked at air quality and health insurance data of almost 40,000 people more than 50 years old who lived in relatively urban areas of Taiwan. They were broken into four categories of pollutant exposure. Those living where concentrations of NO2 and CO were the greatest had the highest rate of age-related macular degeneration. People exposed to the highest levels of NO2 were almost twice as likely to develop the disease, and those who were subjected to the highest CO concentrations had their risk increase by 84%, compared to people exposed to the lowest levels of the pollutants. Those who went through moderate levels of the pollutants didn’t have a significantly higher risk. Dr. Juo stated he was “a bit surprised” that only the highest levels of exposure showed an increased risk. If the exposure goes beyond a certain point, the higher risk starts but below that threshold, there doesn’t seem to be a problem. Juo focused on macular degeneration because the macula is nourished through blood vessels. Pollutants like NO2 and CO are carried through the bloodstream, making the macula physiologically and biologically the most vulnerable part of the eye. NO2 and CO are known to damage cells by creating reactive molecules or free radicals. After nerves in the eye are damaged they can’t repair themselves. Reactive molecules can have many biological effects. They can destroy bacteria and human cells. Their function is to serve as messengers between cells and take part in the process of homeostasis, the process by which our bodies try to maintain stability while adjusting to conditions that are optimal for our survival. Free radicals are atoms that contain an unpaired electron. They seek another electron to stabilize themselves. This process can cause damage to our DNA and cause other harm to our cells. This damage may lead to development of cancer or other diseases and can accelerate the aging process. In the current study pollution levels were measured broadly by documenting levels of NO2 and CO in an area where subjects lived. Juo plans to refine the study and include a more personal measurement of air pollution and hopes the findings will be confirmed when a larger number of people are part of the study. Juo suggests that goggles or other eye protection may not help with protecting against pollution-related macular degeneration because the pollutants enter the macula through the blood system after being inhaled. Avoiding areas of heavy traffic, especially during rush hour, may be more effective. If you have questions about macular degeneration or believe you’re showing symptoms, contact the Lehigh Valley Center for Sight at 610-437-4988 or fill out our contact form so we can start the conversation and work together to protect your sight. Houman Ahdieh, MD Lehigh Valley Center for Sight https://www.lvcenter4sight.com eyedoc@lvcenter4sight.com

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