Higher Air Pollution Exposure Linked to Increased Glaucoma and Cataract Risk: Study

Air pollution may affect more than the heart and lungs. Research suggests that people living in areas with higher pollution levels may face a greater risk of glaucoma and cataract.

Presented at the 44th Congress of the European Society of Cataract and Refractive Surgeons, the research combined findings from 41 observational studies involving millions of people, from East Asia and the UK.

Cataract causes clouding of the eye’s lens and is the leading cause of impaired vision worldwide, affecting about 94 million people. Glaucoma damages the nerve connecting the eye to the brain and can cause permanent vision loss.

Researchers examined several pollutants, including fine particles called PM 2.5 and PM 10, nitrogen dioxide, sulphur dioxide, ozone and carbon monoxide. They compared pollution exposure with diagnoses of glaucoma, cataract and age-related macular degeneration.

The clearest link was seen with PM 2.5, tiny particles found in smoke, vehicle exhaust and industrial pollution. People living in the most polluted areas had up to 70% higher odds of glaucoma than those in the least polluted areas. Higher pollution was consistently linked with a greater risk of cataract.

Researchers estimated that each increase in pollution exposure was associated with about an 8% rise in glaucoma risk and a 4% rise in cataract risk. Evidence for age-related macular degeneration was less consistent, while links with other pollutants were weaker or mixed.

Scientists suggest that fine particles may contribute to inflammation and oxidative stress. Over years, these effects could potentially damage the optic nerve or the eye’s lens. However, because the studies were observational, they cannot prove that air pollution directly causes glaucoma or cataract.

Researchers say further studies, especially in highly polluted regions, are needed. The findings nevertheless add eye health to the reasons for reducing air pollution.

REFERENCE: Ahmed Alnabihi et al.; Smog and sight: epidemiological evidence on the link between air pollution and ocular aging: a comprehensive systematic review and meta-analysis’; European Society of Cataract and Refractive Surgeons