title: A multicentric case-control study on the impact of air pollution on eyes in a metropolitan city of India.
abstract: OBJECTIVE
  To study the effect of exposure to high level of air pollution on ocular surface health.
  
  
  METHODS
  A total of 520 subjects volunteered to participate in this study. All volunteers were required to give a detailed history and were subjected to ophthalmic examination under slit lamp, visual acuity test, tear film break-up time (BUT) and Schrimer's test.
  
  
  RESULTS
  Significantly high number of subjects in study group complained of ophthalmic symptoms compared to control group. Sevent eight per cent subjects in the study group had symptoms such as redness, watering, irritation, strain or photophobia whereas this number was 45% in control group. Schirmer's test showed a significantly low value of 22.75±8.91 mm in study group as compared to 30.30±7.92 mm in control group (P<0.001). Average tear break-up time in study group was significantly low (P<0.05) with a value of 11.17±2.92 seconds compared to 12.13 ± 3.24 seconds in control group.
  
  
  CONCLUSIONS
  Results of our study indicate that people traveling in highly polluted areas and exposed to high level of air pollutants are likely to suffer from significantly high incidence of subclinical ocular surface disorders.
authors.affiliation: Delhi Institute of Pharmaceutical Sciences and Research, New Delhi, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Gupta
authors.forename: S C
authors.initials: SC
authors.lastname: Gupta
authors.forename: Renu
authors.initials: R
authors.lastname: Agarwal
authors.forename: Srivastava
authors.initials: S
authors.lastname: Sushma
authors.forename: S S
authors.initials: SS
authors.lastname: Agrawal
authors.forename: Rohit
authors.initials: R
authors.lastname: Saxena