Prevalence of dry eye disease among Indian pilots: The role of noninvasive diagnostics

Purpose: This study aimed to determine the prevalence of dry eye disease (DED) among Indian commercial pilots and examine its association with prolonged flight hours. Emphasis was placed on the use of the noninvasive average break-up time (NIAvg-BUT) test for diagnosing DED, as opposed to the Schirmer test, highlighting the importance of objective diagnostic methods for this population. Methods: This was a prospective observational cohort study conducted between August and October 2023 at a boarding center designated for medical examinations of civil pilots. A total of 100 civil pilots who underwent routine periodical medical examinations were included. The participants were screened for systemic diseases, ocular allergies, and the use of topical medications. They completed the Ocular Surface Disease Index (OSDI) questionnaire and underwent detailed ophthalmological examinations. The NIAvg-BUT was measured via the Sirius™ corneal topography device. A cutoff value of NIAvg-BUT < 10 seconds was used for diagnosing DED. Results: The incidence of DED among the pilots was 34%. The study revealed a statistically significant association between higher total flying hours and the presence of DED. Pilots with more flying hours had an increased risk of developing DED. Conclusion: This study revealed a high incidence of DED among Indian commercial pilots, which was correlated with prolonged flight hours. This shows the need for objective diagnostic tests, such as the NIAvg-BUT over other invasive tests. Further research is necessary to explore the impact of DED on the functional performance of pilots and the comfort of flight staff and passengers.