Schirmer's test and tear breakup time in an Egyptian population sample: a hospital-based study

Background Dry eye is a very common disease in Egypt. Tear film stability and tear secretion are important factors in the assessment of dry eye disease. Schirmer's test (ST) is used to assess tear secretion, whereas tear breakup time test (TBUT) is used to assess tear film stability. Purpose The aim of this study was to identify the normative data of the ST and TBUT in a sample of Egyptians and to highlight the variables that may significantly affect these values. Patients and methods The study included 150 normal healthy participants. They were divided into different groups according to age, sex, residency, and occupation. History was taken from all participants including ocular surface disease index questionnaire. All participants underwent full ophthalmological examination, ST, and TBUT. Results The mean ST for the population sample was 21.9±9.13 mm, whereas the mean TBUT was 16.04±4.99 s. Studying linear regression for ST with age, sex, occupation, and residency showed that ST was mostly affected by age, where it showed a negative correlation. Studying linear regression for TBUT with age, sex, occupation, and residency showed that TBUT was mostly affected by residency. Conclusion The study allowed us to take an idea about the normative data of ST and TBUT in an Egyptian population and the effect of different variables on both tests.