Ambient air pollution linked to age-related macular degeneration

A United Kingdom study found that individuals with high exposure to ambient air pollution and fine particle matter had an increased risk of age-related macular degeneration (AMD).¹ Data was reviewed from the UK Biobank on 115,956 participants, between 40 to 69 years, and with no history of AMD at baseline in 2006.

Participants

A subset of 52,602 participants contributed data from retinal imaging in 2009 and 2012. All participants reported diagnosis of AMD. In total, 1286 (1.1%) participants reported developing AMD during the time the study took place.

Findings

Those with greater exposure to fine particle matter (PM 2.5) were significantly more likely to develop AMD (odds ratio 1.08). These participants also had thinner photoreceptor synaptic regions (beta -0.16), thicker photoreceptor inner segment layers, (beta 0.04), and thinner retinal pigment epitheliums (beta -0.13). Additionally, thicker photoreceptor synaptic regions (beta 0.04), thicker photoreceptor inner segment layers (beta 0.04), and thinner retinal pigment epitheliums (beta -0.13) were found in participants with higher exposure to nitrogen oxide (N02).

“We have identified yet another health risk posed by air pollution, strengthening the evidence that improving the air we breathe should be a key public health priority," says study co-author Paul Foster, professor of ophthalmic epidemiology and glaucoma studies at the Institute of Ophthalmology, University College London. “Even relatively low exposure to air pollution appears to impact the risk of AMD, suggesting that air pollution is an important modifiable risk factor affecting risk of eye disease for a very large number of people.”

Of the study participants who had retinal imaging and eye assessments performed, 75% were diagnosed with AMD and 12% showed signs of the condition on imaging.

Limitations

In the British Journal of Ophthalmology, the research team noted 2 study limitations. First, the UK Biobank voluntary participants were typically healthier than the general population. Second, outdoor air pollution exposure was estimated based on participants’ home addresses, but different exposure levels could have existed at other locations, such as workplaces. It is also unclear how early- or late-life exposure to air pollution as well as cumulative years of exposure contributes to AMD risk.

Reference

1. Chua SYL, Warwick A, Peto T, et al. Association of ambient air pollution with age-related macular degeneration and retinal thickness in UK Biobank. Br J Ophthalmol. 2021;bjophthalmol-2020-316218. doi:10.1136/bjophthalmol-2020-316218