The Dry Eye Zone

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Abstract: Air pollution role in worsening blepharitis

Ambient levels of air pollution induce clinical worsening of blepharitis.

Even though air pollutants exposure is associated with changes in the ocular surface and tear film, its relationship to the clinical course of blepharitis, a common eyelid disease, had not yet been investigated. Our objective was to investigate the correlation between air pollution and acute manifestations of blepharitis.

We recorded all cases of changes in the eyelids and ocular surface, and rated clinical findings on a scale from zero (normal) to two (severe alterations). Daily values of carbon monoxide, particulate matter smaller than 10μm in diameter and nitrogen dioxide concentrations and meteorological variables (temperature and relative humidity) in the vicinity of the medical service were obtained. Specific linear regression models for each outcome were constructed including pollutants as independent variables (single pollutant models). Temperature and humidity were included as confounding variables.

increases of 28.8μg/m(3) in the concentration of particulate matter and 1.1ppm in the concentration of CO were associated with increases in cases of blepharitis on the day of exposure (5 cases, 95% CI: 1-10 and 6 cases, 95% CI: 1-12, respectively).

Exposure to usual air pollutants concentrations present in large cities affects, in a consistent manner, the eyes of residents contributing to the increasing incidence of diseases of the eyelid margin.

Environ Res. 2011 Dec 26. [Epub ahead of print]
Malerbi FK, Martins LC, Saldiva PH, Braga AL.
Department of Ophthalmology, Hospital Israelita Albert Einstein, São Paulo, Brazil; Environmental Epidemiology Study Group, Laboratory of Experimental Air Pollution, University of São Paulo Faculty of Medical Sciences, São Paulo, Brazil.