A US study focusing on the effects of climate change on eye health revealed clinical visits more than doubled when particulate matter from air pollution was prevalent.  

The study, published in Clinical Ophthalmology, is among the first to look into how climate change may affect the eyes. “The World Health Organization has declared climate change to be the single biggest health threat facing humanity,” said the study’s lead author Assistant Professor Jennifer Patnaik, University of Colorado School of Medicine. “Yet there are limited studies on the impact of climate-change-related air pollution on ocular health.” 

Examining associations between ocular surface irritation and allergy-related daily outpatient office visits with daily ambient particulate matter (PM) levels in the Denver Metropolitan area, researchers obtained data of PM concentrations categorised as ≤10μm (PM₁₀) or ≤2.5μm in diameter. During the study, there were 144,313 ocular surface irritation and allergy visits to ophthalmic clinics, with daily visit counts 1.77 times higher than average with PM₁₀ concentrations of 80μg/m³ and 2.2 times higher when they reached 110μg/m³.  

Conjunctivitis was the second most common eye disease during the study, representing one-third of all visits. The prevalence of ocular allergic conjunctivitis has increased worldwide and socioeconomic and environmental factors – such as temperature, humidity and air pollution – have been proposed as reasons for the increase, A/Prof Patnaik said.  

“Less-studied chronic diseases, such as dementia, have also been shown to be associated with temperature and air pollutants,” she said. “Research on the topic of ocular conditions and climate is still in its early stages; therefore, more studies are needed to better understand how climate and air pollutants impact eye health.”