Living in a more polluted area is associated with a greater likelihood of having glaucoma, according to a new University College London study that appears in Investigative Ophthalmology & Visual Science. People in neighborhoods with higher amounts of fine particulate matter pollution were at least 6% more likely to report having glaucoma than those in the least-polluted areas.

The research team found that people in the most polluted 25% of areas were at least 6% more likely to report having glaucoma than those in the least-polluted quartile, and they were also significantly more likely to have a thinner retina, one of the changes typical of glaucoma progression. Eye pressure was not associated with air pollution, which the researchers say suggests that air pollution may affect glaucoma risk through a different mechanism.

“Air pollution may be contributing to glaucoma due to the constriction of blood vessels, which ties into air pollution’s links to an increased risk of heart problems. Another possibility is that particulates may have a direct toxic effect damaging the nervous system and contributing to inflammation,” said the study’s first author, Sharon Chua, PhD, research fellow, at the University College London Institute of Ophthalmology and Moorfields Eye Hospital, in a news release.