Ocular surface symptoms among individuals exposed to ambient levels of traffic derived air pollution – a cross-sectional study [version 2; referees: 2 approved]

Abstract

Background: The ocular surface is separated by a thin layer of tear film from outdoor air pollutants making individuals exposed to outdoor air pollution prone to various ocular surface disorders. The aim of this study was to determine the magnitude of ocular surface disorders symptoms among traffic police officers of Kathmandu, Nepal. Methods: Two hundred traffic police officers working at different traffic police office branches of Kathmandu, Nepal were invited to the police headquarters for eye and vision examination. Among them, 91 individuals (95% males) completed the ocular surface disease index (OSDI) questionnaire and underwent Schirmer’s I tear test. Results: Symptoms of ocular surface disorders were reported by over 80% of the individuals. Approximately two-fifths of the individuals (38%) reported severe symptoms. Only 17% of the individuals’ tear secretion was found to be below normal using the Schirmer’s tear test. No significant association was observed between the OSDI score and Schirmer’s tear test scores (r = 0.008, p = 0.94). A weak but significant relationship was observed between the OSDI score and job duration (r=0.21,p = 0.04). Individual exposed to outdoor air pollution for more than 10 years had higher odds of reporting ocular surface complaints as compared to those who were exposed for less than 10 years (OR = 3.94, p = 0.02). Conclusion: Ocular surface disorder symptoms are common among traffic police officers of Kathmandu, Nepal. The duration of exposure appears to significantly contribute to the increased symptoms in this exposed population.