When we think about pollution and especially the impact of climate change, it is difficult to think of eyes. Yet these “windows” onto the outside world are affected by environmental situation. This is confirmed by an analysis published in Clinical Ophthalmology, coordinated by Jennifer Patnaik, professor at the University of Colorado.
Pollution doubles the risks of outpatient visits
The research adds a piece to the knowledge on the relationship between ocular well-being and the environment. The investigators examined associations between ocular surface irritation and daily office visits related to allergies with daily PM (airborne particulate matter) levels in the Denver metro area. In particular, the concentrations of PM10 and PM relating to particles 2.5 micrometers or less in diameter. 144,313 visits for ocular surface irritation and allergies to specialized centers were analyzed throughout the analysis period.
Result. Daily visits more than doubled (2.2-fold increase) in the presence of high PM10 concentrations (around 110). Not only that. There is a direct relationship between increase in eye checks and increase in daily concentrations of pollutants.
There conjunctivitis it was the second most common eye disease encountered during the visit. On average, one in three controls was associated with this pathology. Obviously the allergic formsregardless of the seasons, were particularly frequent, confirming the increasing trend of these paintings found on a global scale. Among the external elements that seem to be associated with this observation would be changes in temperature, humidity and air pollution.
What happens in case of dry eye
Dry eye is linked to an alteration of the tear film which causes damage to the ocular surface associated with symptoms of ocular discomfort. The tear film is a thin liquid film, arranged on the ocular surface, made up of 3 layers:
- lipid, the outermost one which prevents evaporation
- aqueous, most often, containing oxygen, nutrients and defense substances
- mucous, the innermost, in contact with the cornea.
Thanks to the tear film, the eye is lubricated, also due to the blinking made possible by the presence of tear film which lubricates the surface itself. Eyelid blinking determines a continuous distribution of tears in a regular manner so as to constitute an optically valid homogeneous surface. Furthermore, the “film” defends the eye by washing and removing waste substances and preventing germs from proliferating and taking root.
The alteration of the tear film responsible for “dry eye” can be quantitative due to a deficit of the aqueous component (hypolacrimia) or qualitative (dyslacrimia) for alterations of one of the three components (aqueous, lipid, mucosa) and for mechanical alterations (eyelid, blinking, ocular surface anomalies, contact lenses, hypoesthesia).
The most frequent symptoms are: burning, foreign body sensation, vision disorders, photophobia, sense of weight, pain, ocular tiredness. Between the risk factors the climate and the air you breathe also play an important role. Excessive exposure to air conditioning, dry climate, smog and cigarette smoke can worsen the condition.
How important air quality is for health
The study, as the experts point out, highlights the systemic impacts on the health of peopleclimate stressincluding air quality, wildfires, temperature and drought conditions. And above all it highlights how the particulate matter can have an effect on ocular well-being and beyond. Recently it has emerged how to reduce the risk of development and exacerbation of skin pathologiesin particular atopic dermatitis, there is a need for environmental policy strategies that limit the use of fossil fuels, promote sustainable land management practices by reducing the amount of air pollution and provide for the installation of air filtering devices in indoor environments .
Numerous studies have in fact demonstrated not only the connection between climate changes and increase in atopic dermatitisbut also between environmental pollution and an increase in pathology. Furthermore, the growing trend in air pollution, mainly due to the increase in motor vehicles and the use of coal for the production of electricity, impacts human health from pre-natal age.
More generally, in short, any environmental aspect influences the development of chronic diseases in an individual, both during conception and pregnancy up to older age.
From a conceptual point of view we are no longer talking about environmental causesbut of exposomea term initially used only in reference to the development of tumors, but which today also refers to the field of allergies and which was introduced a few years ago to indicate the totality of non-genetic environmental exposures to which an individual is subjected, and from the whole of the effects of the environment, to viruses, to pollution, to climate change.
