Air pollution is linked to an increased risk of irreversible sight loss, study finds

Researchers from UCL found that air pollution was linked to irreversible sight loss.

London (CNN)Increases in air pollution are linked to an increased risk of irreversible sight loss, according to a new study.

Researchers from University College London (UCL) found that even low exposure to air pollution across England, Scotland and Wales appears to impact the risk of age-related macular degeneration (AMD).
AMD is the leading cause of irreversible blindness among people over 50 in high-income countries. AMD is linked to the loss of central vision -- needed for reading, performing fine detailed tasks and recognizing faces -- and the biggest risk factors for the disease are genetics, old age and smoking.
    Researchers found that people living in the most polluted areas were at least 8% more likely to report having the condition, in a study published Monday in the British Journal of Ophthalmology.
      The team studied data from 115,954 people aged between 40-69, who had participated in the UK Biobank, a large study of half a million people focusing on the medical diagnoses and biological measurements of participants.
      Using eye measurements and data from questionnaires, experts studied those who said they did and did not have macular degeneration, and then compared the results to the amount of pollutants estimated to be at their residential addresses.
      "People who live in a more polluted area report macular degeneration more frequently," Paul Foster, a professor of glaucoma studies and ophthalmic epidemiology at UCL and senior author of the paper, told CNN.
        Foster said that the main pollutants linked to macular degeneration were particulate matter PM2.5, nitrogen dioxide and oxide nitrogen.
        PM2.5 is tiny particulate pollution that can move deep into the lungs when inhaled and enter the bloodstream. The particles, made up of dust, dirt, soot or smoke, originate from construction sites, unpaved roads, fields, smokestacks or fires, and can contain different chemicals. But most particles are a mix of pollutants from power plants, industrial and vehicle emissions.
        Particulate matter is emitted during the combustion of solid and liquid fuels, such as for power generation, domestic heating and in vehicle engines.
        Nitrogen oxides refers to nitric oxide gas and nitrogen dioxide gas, as well as other gaseous oxides containing nitrogen. The main source of these gases in urban areas are motor vehicle exhausts, indoor gas stoves and kerosene heaters.
        Foster told CNN that the pollutants enter the body through the lungs, and seem to cause particular damage to the eyes because of high blood flow in the eye wall.