Add Eye Disease To The Growing List Of Air Pollution’s Dangers

Dirty Air Linked To Higher Glaucoma and Cataract Risk, Large Study Finds

For decades, warnings about dirty air have centered on the heart and lungs, organs long known to absorb the damage from soot, exhaust and industrial smoke. A large new analysis suggests the eyes deserve a place on that list too. Researchers pooled data from 41 studies covering millions of people across East Asia and the United Kingdom and found that people living in more polluted areas face a higher risk of both glaucoma and cataract, two of the leading causes of vision loss worldwide.

Dr. Ahmed Alnabihi of King Khaled Eye Specialist Hospital and Research Center in Riyadh, Saudi Arabia, presented the findings Monday at the European Society of Cataract and Refractive Surgeons Congress in London. He said eye damage from pollution has lagged behind better-studied harm to the heart and lungs. “We’ve known for years that air pollution damages the lungs and heart, but its effects on the eyes have been much less studied and the existing evidence was scattered and inconclusive.”

Alnabihi described what pushed him to look closer. “Every day, we see patients losing vision to conditions like glaucoma and cataract. These diseases are labelled as ‘age related’ as though aging is the only culprit, but that always felt incomplete to me. If something environmental is accelerating these conditions, that changes our thinking and suggests we could take action to reduce the risks.”

Air Pollution Has a Direct Line to the Eyes

Unlike the heart or lungs, tucked inside the chest, the eye sits fully exposed to whatever is in the air. Its outer surface, the tear film, conjunctiva and cornea, has nothing between it and the surrounding atmosphere. That direct exposure is part of why researchers think fine particulate matter, the tiny particles produced by smoke, vehicle exhaust and industrial pollution, small enough to travel deep into the body, may be driving the pattern the analysis found. Alnabihi said fine particles are thought to cause inflammation and oxidative stress in the body. Over years of exposure, those effects may damage the optic nerve, which is involved in glaucoma, or the lens, which is involved in cataract.

Air Pollution and Eye Disease, by the Numbers

Forty-one separate observational studies feed the analysis, drawing on some of the largest eye health databases in the world. People living in the most polluted areas had up to 70 percent higher odds of glaucoma than those in the cleanest air. Cataract risk climbed too, rising alongside pollution levels. For every meaningful step up in exposure to fine particulate matter, glaucoma risk rose by about 8 percent and cataract risk by about 4 percent, according to Alnabihi. Links to age-related macular degeneration were less consistent, and other pollutants, including nitrogen dioxide and ozone, showed weaker associations.

Dr. Filomena Ribeiro, the ESCRS’s immediate past president and head of ophthalmology at Hospital da Luz in Lisbon, who had no role in the research, called the finding an addition to a familiar list. Cataract already affects roughly 94 million people worldwide and glaucoma about 7.7 million, she noted. Ribeiro said: “Both conditions become more common as we get older, but this study indicates that people who are exposed to higher levels of air pollution are also facing a greater risk.” Air quality, long framed as a matter for hearts and lungs, now has a claim on eyesight too.

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