DIAGNOSTIC USEFULNESS AND CUTOFF VALUE OF SCHIRMERS-I TEST IN THE JAPANESE DIAGNOSTIC-CRITERIA OF DRY EYE

Background: Recently, the diagnostic criteria of dry eye have been ten tatively approved in Japan. The aim of this study was to evaluate the diagnostic usefulness and the cutoff value of Schirmer's I test on app lying these Japanese diagnostic criteria to patients with Sjogren's sy ndrome. Methods: One hundred eyes of 50 patients with Sjogren's syndro me underwent a series of diagnostic tests, including Schirmer's I test , cotton thread test, tear film break-up time (BUT), fluorescein stain ing, and rose bengal staining. They were classified into definite dry eye, probable dry eye, and normal eye according to the Japanese criter ia. The diagnostic usefulness of Schirmer's I test was evaluated in co mparison with that of the cotton thread test or BUT, based on the diag nostic outcome by combination of the individual tests plus vital stain ing tests. The cutoff value of Schirmer's I test was evaluated, based on the results of sensitivity and specificity rates at each cutoff val ue from 0 to 10 mm. Results: The diagnostic usefulness of Schirmer's I test was inferior to that of BUT, but superior to that of cotton thre ad test. The sensitivity and specificity were 80% and 53%, respectivel y, at a cutoff value of 5 mm and 88% and 35%, respectively, at a cutof f value of 10 mm. Conclusion: In investigation of dry eye, both Schirm er's I test and BUT should be performed to detect tear abnormalities. The cutoff value of 5 mm in Schirmer's I test seems to be justified pr ovided that the purpose of the test is comparison of inter-institution al data, not screening.