Association of long-term exposure to ambient air pollution with retinal neurodegeneration: the prospective Alienor study

Laure Gayraud; Marion Mortamais; Cédric Schweitzer; Kees de Hoogh; Audrey Cougnard-Grégoire; Jean-François Korobelnik; Marie-Noelle Delyfer; Marie-Bénédicte Rougier; Karen Leffondré; Catherine Helmer; Danielle Vienneau; Claudine Berr; Cécile Delcourt

doi:10.1016/j.envres.2023.116364

Association of long-term exposure to ambient air pollution with retinal neurodegeneration: the prospective Alienor study

Environ Res. 2023 Sep 1:232:116364. doi: 10.1016/j.envres.2023.116364. Epub 2023 Jun 8.

Affiliations

¹ University of Bordeaux, INSERM, BPH, U1219, F-33000, Bordeaux, France.
² University of Montpellier, INSERM, Institute for Neurosciences of Montpellier INM, UMR1298, F-34091, Montpellier, France.
³ University of Bordeaux, INSERM, BPH, U1219, F-33000, Bordeaux, France; CHU de Bordeaux, Service d'Ophtalmologie, INSERM, U1219, Bordeaux, France.
⁴ Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
⁵ University of Bordeaux, INSERM, BPH, U1219, F-33000, Bordeaux, France. Electronic address: cecile.delcourt@u-bordeaux.fr.

PMID: 37301495
DOI: 10.1016/j.envres.2023.116364

Abstract

Chronic exposure to air pollution may have adverse effects on neurodegenerative diseases. Glaucoma, the second leading cause of blindness worldwide, is a neurodegenerative disease of the optic nerve, characterized by progressive thinning of the retinal nerve fiber layer (RNFL). We investigated the relationship of air pollution exposure with longitudinal changes of RNFL thickness in the Alienor study, a population-based cohort of residents of Bordeaux, France, aged 75 years or more. Peripapillary RNFL thickness was measured using optical coherence tomography imaging every 2 years from 2009 to 2020. Measurements were acquired and reviewed by specially trained technicians to control quality. Air pollution exposure (particulate matter ≤2.5 μm (PM_2.5), black carbon (BC), nitrogen dioxide (NO₂)) was estimated at the participants' geocoded residential address using land-use regression models. For each pollutant, the 10-year average of past exposure at first RNFL thickness measurement was estimated. Associations of air pollution exposure with RNFL thickness longitudinal changes were assessed using linear mixed models adjusted for potential confounders, allowing for intra-eye and intra-individual correlation (repeated measurements). The study included 683 participants with at least one RNFL thickness measurement (62% female, mean age 82 years). The average RNFL was 90 μm (SD:14.4) at baseline. Exposure to higher levels of PM_2.5 and BC in the previous 10 years was significantly associated with a faster RNFL thinning during the 11-year follow-up (-0.28 μm/year (95% confidence interval (CI) [-0.44;-0.13]) and -0.26 μm/year (95% CI [-0.40;-0.12]) per interquartile range increment; p < 0.001 for both). The size of the effect was similar to one year of age in the fitted model (-0.36 μm/year). No statistically significant associations were found with NO₂ in the main models. This study evidenced a strong association of chronic exposure to fine particulate matter with retinal neurodegeneration, at air pollution levels below the current recommended thresholds in Europe.

Keywords: Air pollution; Central nervous system (CNS); Glaucoma; Neurodegeneration; Retina; Retinal nerve fiber layer (RNFL).

MeSH terms

Aged, 80 and over
Air Pollution* / adverse effects
Female
Humans
Male
Neurodegenerative Diseases* / chemically induced
Neurodegenerative Diseases* / epidemiology
Nitrogen Dioxide
Particulate Matter
Prospective Studies
Retinal Ganglion Cells

Substances

Nitrogen Dioxide
Particulate Matter