AUTHOR=Singh Swati , Srivastav Saumya , Mohamed Ashik , Basu Sayan 

TITLE=Non-invasive Tear Film Assessment in Normal Population: Effect of Age, Sex, and Interparametric Relationship

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.894184

DOI=10.3389/fmed.2022.894184

ISSN=2296-858X

ABSTRACT=<sec><title>Purpose:</title><p>To investigate age- and sex-related differences in tear film parameters of normal Indian population and study interparametric relationships.</p></sec><sec><title>Methods</title><p>Healthy subjects with no ocular disease (median ocular surface disease index = 0) were subjected to an automated evaluation of tear meniscus height (TMH), non-invasive tear breakup time (NIBUT) using Keratograph 5M (OCULUS GmbH, Wetzlar, Germany), and tear osmolarity using the TearLab Osmolarity System (TearLab Corporation, California, USA). A mixed-effects model with random intercepts at the patient level was used to evaluate the relationships between explanatory (age, gender, and tear osmolarity) and outcome variables (TMH and NIBUT).</p></sec><sec><title>Results</title><p>A total of 237 subjects (474 eyes; 150 males) were enrolled with a mean age of 40 ± 17 years (range, 10-78 years). The mean values (± standard deviation) of TMH, NIBUT, and tear osmolarity were 0.34 ± 0.07 mm, 10.95 ± 2.02 s and 289.0 ± 5.8 mOsm/L, respectively. Age had a significant positive relationship with TMH (<italic>p</italic> &lt; 0.0001; 0.002 mm/year; r = 0.12), but there was no effect on NIBUT (<italic>p</italic> = 0.26) and tear osmolarity (<italic>p</italic> = 0.27). There were no sex-based differences in tear film parameters. Interparametric relationship revealed no significant association between TMH and NIBUT (<italic>p</italic> = 0.12) or tear osmolarity and TMH (<italic>p</italic> = 0.83) or tear osmolarity and NIBUT values (<italic>p</italic> = 0.48).</p></sec><sec><title>Conclusions</title><p>In a normal Indian population, TMH is weakly affected by age and is independent of sex, NIBUT, and tear osmolarity. Tear breakup time and osmolarity show no significant age- and sex-related variation.</p></sec>