A large long-term study conducted by researchers from University College London has found that living in an area with high levels of air pollution can increase your risk of developing macular degeneration by 8%.

The 115,954 participants in the study were aged 40–69 when it began in 2006 and reported no existing issues with their vision. They were monitored for the development of AMD and results were analysed alongside the average level of air pollution where they lived.

It was found that greater concentrations of air pollution were associated with up to an 8% increase in the likelihood of developing macular degeneration.

Lead author of the study, Professor Paul Foster from UCL’s Institute of Ophthalmology, said, “Here 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. Our findings suggest that living in an area with polluted air, particularly fine particulate matter or combustion-related particles that come from road traffic, could contribute to eye disease. 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 participants, 52,602 had their eyes examined and assessed for structural changes in the thickness and numbers of light receptors in the retina which are characteristic of age-related macular degeneration.

The study used estimates of the average annual levels of air pollution where each participant lived, considering pollutants such as fine particles (PM2.5), nitrogen dioxide and nitrogen oxide. Researchers found that just over 1% of the study group ended up being diagnosed with age-related macular degeneration. After accounting for potentially influential factors, including underlying health conditions and lifestyle, analysis of the data showed that higher fine particulate matter (PM2.5) exposure was associated with an 8% higher risk of developing AMD.

Although this study was observational in nature and doesn’t establish cause, the researchers state that these findings echo those found elsewhere in the world, “Overall, our findings suggest that ambient air pollution, especially fine [particulate matter] or those of combustion-related particles, may affect AMD risk. It is possible that the structural features observed may be unrelated to AMD, but associated with pollution-induced retinal toxicity. However, the direction of the relationships between air pollution and both AMD and associated retinal layer thicknesses indicate higher exposure to air pollution may make the cells more vulnerable and increase the risk of AMD. Our findings add to the growing evidence of the damaging effects of ambient air pollution, even in the setting of relative low exposure. If [they] are replicated, this would support the view that air pollution is an important modifiable risk factor for AMD.”

Sources:

1. BMJ.
2. UCL.
3. The Guardian.
4. The Times.