Air pollution may be linked to increased risk of glaucoma A new study examines the link between air pollution and glaucoma. Glaucoma is an eye disease in which pressure builds up in the eye, which can lead to pressure and damage to the optic nerve at the back of the eye, which transmits signals to the brain. In the most common type of glaucoma, called primary open angle, pressure buildup occurs gradually over several years, and the disease is usually hereditary, along with other risk factors, including aging and originating in Asia, Africa or the Caribbean. In this British study, more than 100,000 people completed questionnaires and had eye exams for glaucoma. The researchers linked the data to the level of pollution in the family home in the same year, and about 2 percent of the self-reported sample was diagnosed with glaucoma. The researchers found that the chance of self-reporting increased by 6 percent in areas with more pollution. They also found that higher pollution was associated with the thickness of nerve fibers in the back of the eye, another marker of glaucoma. These associations warrant further study, but they do not definitively prove that pollution is responsible for these effects, as many unmeasured factors may be involved. The study was conducted by researchers from Moorfields Eye Hospital, University College London, Cardiff University and the University of Bristol. Funding was provided by the National Institutes of Health, Moorfields Eye Charity and the Department of Health. The study was published in the peer-reviewed journal Ophthalmology & VisualScience and is available free online. Researchers analyzed the association between glaucoma and PM2.5 and considered potential confounders for age, gender, race, body mass index (BMI), smoking status and vision in a final survey sample of 111,370 people, including those who completed the questionnaire and had an eye exam, and excluded those with diabetic eye disease, eye surgery or any other serious eye disease. Glaucoma was reported to have been diagnosed in 1.8 percent of the sample (2,040 adults). a per-quartile increase in PM2.5 was associated with a 6 percent increase in the chance of self-reporting. Thus greater exposure to PM2.5 would be associated with self-reported glaucoma and poor structural features of the disease. the absence of an association between PM2.5 and IOP suggests that the relationship may be through non-pressure-dependent mechanisms, possibly for neurotoxic effects or vascular effects.” The World Health Organization (WHO) lists air pollution as one of the major contributors to global diseases (especially respiratory diseases, but also possibly cardiovascular and neurological diseases). Considering that they did not find the increased pressure typically seen in glaucoma, they suggest that pollution may cause other damage to the nerve fibers or blood vessels in the eye, but this study does not prove a direct cause-and-effect relationship. In conclusion, glaucoma can be effectively treated if caught early, and the most important thing is to make sure you have regular eye exams.