The Repeatability, Reproducibility, and Correlation of the Schirmer Test: A Comparison of Open versus Closed Eye

PURPOSE: To compare the repeatability and reproducibility of the Schirmer test (ST) without anesthesia when the eyes are open (STo) and closed (STc) in previously undiagnosed patients with suggestive symptoms of dry eye. METHODS: In a comparative, observational series case study, 31 patients were included in the study. STo and STc were alternately applied for a total of six times. The ST was applied two times with the eyes open (S1) and closed (S2), respectively, by a single ophthalmologist. Then the ST was repeated four times with the eyes open (S3, S5) and closed (S4, S6), respectively, by a single nurse. RESULTS: S1, S3, and S5 were 23.4, 23.7, and 23.3 mm, respectively. S2, S4, and S6 were 14.7, 15.6, and 16.6 mm, respectively. STc scores were found to be statistically lower than the STo’s in general (right: t = 2.033, p = 0.048; left: t = 3.474, p = 0.004). There was no statistically significant difference in the scores of the three tests with open eyes: S1, S3, and S5 (p = 0.462). There was also no statistically significant difference in the scores of the three tests with closed eyes: S2, S4, and S6 (p = 0.05). CONCLUSIONS: Our study suggests that although administering the ST with the patient’s eyes open produces higher readings than STc in patients with suggestive symptoms of dry eye, there was an acceptable reliability among tests performed open and closed. Moreover, intraexaminer reliability was higher than interexaminer reliability for both with the eyes open and closed.