BRITS are at greater risk of going blind if they live near a busy road, a study suggests.
Experts found those residing on more polluted streets were six per cent more likely to develop glaucoma than people who enjoyed plenty of fresh air.
Nearly half a million adults have the eye-condition in the UK, which results in permanent damage to the optic nerve.
Although treatable if caught early, glaucoma remains one of the leading causes of blindness globally.
Scientists from University College London analysed date more than 110,000 older Brits given eye tests between 2006 and 2010.
Those who lived in areas with the worst air pollution had higher rates of glaucoma.
‘Public health priority’
Lead researcher Professor Paul Foster said: “We have found yet another reason why air pollution should be addressed as a public health priority and that avoiding sources of air pollution could be worthwhile for eye health alongside other health concerns.
“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.
“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.”
Narrowing blood vessels
Experts think air pollution may lead to narrowing of blood vessels in the eye.
The findings, published in the journal Investigative Ophthalmology & Visual Science, were based on 111,370 participants of the UK Biobank study cohort who underwent eye tests from 2006 to 2010 at sites across Britain.
The participants were asked whether they had glaucoma and underwent ocular testing which measured intraocular pressure, and a laser scan of the retina.
Their data was linked to air pollution measures for their home addresses, from the Small Area Health Statistics Unit, with the researchers focusing on fine particulate matter – equal or less than 2.5 micrometres in diameter, or PM2.5.
What is glaucoma?
Glaucoma is a common eye condition where the optic nerve, which connects the eye to the brain, becomes damaged.
It’s usually caused by fluid building up in the front part of the eye, which increases pressure inside the eye.
Glaucoma can lead to loss of vision if it’s not diagnosed and treated early.
It can affect people of all ages, but is most common in adults in their 70s and 80s.
Glaucoma does not usually cause any symptoms to begin with.
It tends to develop slowly over many years and affects the edges of your vision first.
For this reason, many people do not realise they have glaucoma, and it’s often only picked up during a routine eye test.
The study’s first author, Dr Sharon Chua of UCL’s Institute of Ophthalmology and Moorfields Eye Hospital, said: “Air pollution may be contributing to glaucoma due to the constriction of blood vessels, which ties into air pollution’s links to an increased risk of heart problems.
“Another possibility is that particulates may have a direct toxic effect damaging the nervous system and contributing to inflammation.”
Particulate matter exposure is one of the strongest predictors of mortality among air pollutants, scientists say.
Prof Foster added: “We found a striking correlation between particulate matter exposure and glaucoma. Given that this was in the UK, which has relatively low particulate matter pollution on the global scale, glaucoma may be even more strongly impacted by air pollution elsewhere in the world.
“And as we did not include indoor air pollution and workplace exposure in our analysis, the real effect may be even greater.”