Air pollution is known to have a deleterious effect on overall human health, including ocular health, according to a United Kingdom-based research team. Their study, published in Investigative Ophthalmology and Visual Science, specifically offers evidence that air pollution can adversely affect retinal structural features.
Researchers examined data from 51,710 participants to determine whether ambient air pollution particulates and nitrogen oxides had any effect on retinal health and morphology. Measurements and imaging of the retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCL-IPL), outer plexiform layer, outer nuclear layer, photoreceptor inner, and outer segments, and retinal pigment epithelium were taken via spectral domain optical coherence tomography (SD-OCT).
The results show a significant correlation between air pollution exposure and ocular morphology changes with a greater apparent effect on inner retinal layers when compared with outer retinal layers. Furthermore, finer pollution particulates seemed to have greater adverse effects on retinal structure. Specifically, participants exposed to greater particulate matter with an aerodynamic diameter of less than 2.5 μm (PM 2.5) and higher nitrogen oxides were more likely to have thicker RNFLs and thinner GCL-IPLs, inner nuclear layer, and outer plexiform layers and outer nuclear layers (P <.001). However, study participants who resided in areas of higher levels of PM 2.5 absorbance were more likely to have thinner RNFLs as well as thinner inner nuclear layer, and outer plexiform layers.
Participants who had a self-reported diabetes-related eye disease, ocular injury resulting in serious damage, or who had poor SD-OCT signal strength and image quality were excluded from the study.
Participants were all between 40-69 years old and researchers adjusted for common variables including age, sex, race, smoking status, refractive error, body mass index, and Townsend deprivation index. A multivariable regression study was conducted to compare retinal integrity and exposure to pollutants of various sizes, including nitric oxides. Air pollution measurements were provided by the Small Area Health Statistics Unit and linked centrally to the assessment data by the UK Biobank analysts.
The results of the study confirmed a significant association between pollution and retinal morphology changes and drew a parallel between early morphology changes as predisposing factors to common ocular diseases such as glaucoma and age-related macular degeneration.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Chua S, Khawaja A, Dick A; f The UK Biobank Eye and Vision Consortium. Ambient air pollution associations with retinal morphology in the UK Biobank. Invest Ophthalmol Vis Sci 2020;61(5):32. doi: https://doi.org/10.1167/iovs.61.5.32.