The effect of pregnancy on tear osmolarity.

Objective: To examine the effect of pregnancy on the lacrimal system through tear osmolarity measurement and the Schirmer test.
Material and Method: The study consisted of two groups of 30 women between 20 and 40 years old; the women in the study group were in their first trimester of pregnancy, and the women in the control group were not pregnant and did not have any diseases other than refractive error. Tear osmolarity measurement with the TearLab osmolarity system and tear function test Schirmer 1 were carried out on one, randomly chosen eye of each participant. The pregnant women's measurements were repeated on the same eye in their last trimester.
Results: The study group's first trimester tear osmolarity measurement was 304.9 ± 8.0 mOsm/L, while their last trimester tear osmolarity measurement was 300.2 ± 7.1mOsm/L and the control group's was 306.3 ± 6.2 mOsm/L. There was a statistical difference between the study group's first and last trimester results and between the study group's last trimester and the control group's results (p < 0.05). The Schirmer test results were 18.1 ± 6.3 mm for the study group's first trimester, 16.6 ± 6.9 mm for the last trimester and 21.3 ± 9.0 mm for the control group. There was a statistically significant difference between the study group's last trimester results and the control group's Schirmer test results (p < 0.05).
Conclusion: Both the tear osmolarity values and Schirmer values were found to decrease significantly towards the end of pregnancy. These results suggest that decrease in both test results may play a protective role in the ocular surface during pregnancy.
(Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)