Air Pollution Linked to Increased Risk of Glaucoma

New research from University College London has found a potential link between increased air pollution and risk of glaucoma.

An analysis of more than 100,000 revealed people living in neighborhoods with a greater amount of fine particulate matter (PM2.5) were at least 6% more likely to report having glaucoma.

"Most risk factors for glaucoma are out of our control, such as older age or genetics. It's promising that we may have now identified a second risk factor for glaucoma, after eye pressure, that can be modified by lifestyle, treatment or policy changes," said lead investigator Paul Foster, PhD, professor at the UCL Institute of Ophthalmology and Moorfields Eye Hospital, in a press release.

In an effort to evaluate how increased levels of air pollution could play a role in glaucoma, investigators conducted an assessment on 111,370 participants in the UK Biobank study cohort. All participants included in the analyses underwent eye tests from 2006 to 2010, which included assessments of demographic, socioeconomic, lifestyle, and ocular disease information as well as glaucoma status.

Patients included in the study underwent ocular assessments that included measurements of refractive error and intraocular pressure (IOP)—for patients using IOP-lowering medication, investigators imputed pretreatment IOP by dividing by 0.7, based on mean IOP reduction achieved by medication. Patients also underwent SD-OCT imaging to evaluate the thickness of the ganglion cell layer and inner plexiform layer in the macula—investigators average thickness of GCIPL across all 9 ETDRS retinal subfields were used in the analysis.

Upon analyses, investigators observed patients in areas with higher PM2.5 concentration were at least 6% more likely to report a diagnosis of glaucoma compared to those in the less polluted areas(OR 1.06, 95% CI: 1.01-1.12, per IQR increase P=0.02). Additionally, investigators noted associations between patients living in an area with higher PM2.5 concentration and thinner GCIPL as well as a dose-response relationship between higher levels of PM2.5 and thinner GCIPL (P<0.001). No clinically relevant relationship was observed between PM2.5 concentration and IOP.

Despite the study focusing on the patients in the United Kingdom, investigators suggest the results highlight the need for further research to evaluate the potential link between particulate matter exposure and glaucoma.

"While we cannot confirm yet that the association is causal, we hope to continue our research to determine whether air pollution does indeed cause glaucoma, and to find out if there are any avoidance strategies that could help people reduce their exposure to air pollution to mitigate the health risks,“ said Foster in the same release.

This study, titled “The Relationship Between Ambient Atmospheric Fine Particulate Matter (PM2.5) and Glaucoma in a Large Community Cohort,” was published online in Investigative Ophthalmology & Visual Science.