Air pollution ‘can trigger glaucoma’: Study finds chemicals in air narrow the blood vessels and raise the risk of the condition by 6%

• Pollution may cause retina cells to die due to the constriction of blood vessels 
• University College London (UCL) looked at more than 100,000 Brits in the study
• Found those in most-polluted quarter of areas 6% more likely to have condition

Living in highly polluted areas may increase your risk of going blind, a study suggests.

Researchers found people breathing in high amounts of air pollution were at least six per cent more likely to develop glaucoma than those in clean regions.

The disease, caused by the death of retina cells at the back of the eye, affects 60million people around the world, a 10th of whom have gone completely blind. 

Around 500,000 people in the UK, and more than 2.7million Americans, suffer from the condition.  

Scientists believe air pollution may cause glaucoma due to the constriction of blood vessels killing off the retina cells or by chemicals being directly toxic to nerves.

Living in highly polluted areas increases your risk of developing glaucoma by 6 per cent, scientists suggest (file)

Scientists say the microscopic particles emitted by cars and industry are breathed deep into the lungs and enter the bloodstream. 

From there they constrict the linings of the blood vessels and the nervous system, and raise blood pressure. 

Researchers from University College London (UCL) looked at 111,370 participants from the UK Biobank study who had eye tests from 2006 to 2010.

The data was then cross-referenced with air pollution levels using volunteers’ home addresses.

Glaucoma is a condition which can affect sight, usually due to build up of pressure within the eye.

It often affects both eyes, usually to varying degrees. One eye may develop glaucoma quicker than the other.

The eyeball contains a fluid called aqueous humour which is constantly produced by the eye, with any excess drained though tubes.

Glaucoma develops when the fluid cannot drain properly and pressure builds up, known as the intraocular pressure.

This can damage the optic nerve (which connects the eye to the brain) and the nerve fibres from the retina (the light-sensitive nerve tissue that lines the back of the eye).

In England and Wales, it’s estimated more than 500,000 people have glaucoma but many more people may not know they have the condition.

Worldwide, it is the second leading cause of blindness, according to the World Health Organisation.

Glaucoma can be treated with eye drops, laser treatment or surgery. But early diagnosis is important because any damage to the eyes cannot be reversed. Treatment aims to control the condition and minimise future damage.

If left untreated, glaucoma can cause visual impairment. But if it’s diagnosed and treated early enough, further damage to vision can be prevented.

Source: NHS Choices 

People in the most polluted quarter of neighbourhoods were at least six per cent more likely to report having glaucoma than those in the least polluted.

They were also significantly more likely to have a thinner retina – one of the tell-tale signs of early glaucoma.

Lead author Professor Paul Foster, from the UCL Institute of Ophthalmology and Moorfields Eye Hospital, said: ‘We have found yet another reason why air pollution should be addressed as a public health priority. 

‘Avoiding sources of air pollution could be worthwhile for eye health alongside other health concerns.

‘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.’    

Professor Foster said the link could be much more widespread in other countries where air pollution is rife.

He added: ‘And as we did not include indoor air pollution and workplace exposure in our analysis, the real effect may be even greater.’

One in every 50 people over the age of 40 has early signs of glaucoma, although the vast majority go undetected at this stage. That figure rises to one in 10 of those aged over 75. 

The number of people affected is expected to increase in the next few years due to an ageing population.     

The research was published in the journal Investigative Ophthalmology & Visual Science. 

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