title: Tear pH, air pollution, and contact lenses.
abstract: We analyzed the tear pH of a random sample of 100 subjects, divided into 3 groups according to the stability of their precorneal tear film (normal eyes, borderline; and dry eyes). The average pH value obtained was 7.52. The pH for borderline and dry eyes was higher than for normal eyes. The purpose of this study was to determine the influence of air pollution, specifically sulfur dioxide (SO2), on the tear pH. We found that air pollution affected the lacrimal pH, which decreased when the atmospheric SO2 increased. Finally, we studied the effect of soft contact lens wear on tear pH after 7 days of contact lens adaptation by assessing the tear pH decrease. We took into account the influence of the sex and age of subjects on the results obtained.
authors.affiliation: School of Ophthalmic Optics, Division of Health Science, University of Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Andrés
authors.forename: M L
authors.initials: ML
authors.lastname: García
authors.forename: M
authors.initials: M
authors.lastname: Espina
authors.forename: J
authors.initials: J
authors.lastname: Valero
authors.forename: O
authors.initials: O
authors.lastname: Valls
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000397:Air Pollution / Q000009:adverse effects*; D002648:Child; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D013458:Sulfur Dioxide / Q000009:adverse effects; D013666:Tears / Q000187:drug effects / Q000378:metabolism*
chemical_list: D013458:Sulfur Dioxide