Sensitivity of Diagnostic Tests for Dry Eye in Patients with Blepharospasm

The aim of the study was to evaluate diagnostic tests for keratoconjunctivitis sicca (Schirmer test, tear break-up time (TBUT) test, and corneal staining with fluorescein and lissamine green dye) in patients with blepharospasm. This prospective study included 60 female patients older than 40 with blepharospasm, divided into two groups according to clinical symptoms. For fluorescein test, the surface under the ROC curve was 1.0 with standard error (SE) 0 and 95% confidence interval (95% CI) 0.940-1.0; for Schirmer test, the surface under the ROC curve was 0.817 with SE 0.0555 and 95% CI 0.696-0.905; for lissamine green test, the surface under the ROC curve was 0.813 with SE 0.056 and 95% CI 0.691-0.902; and for TBUT test, the surface under the ROC curve was 0.772 with SE 0.061 and 95% CI 0.645-0.870. According to the results of ROC curve, which determines the sensitivity and specificity of normal values, comparison of diagnostic tests for keratoconjunctivitis sicca used in this study showed that fluorescein test had the best sensitivity and specificity. Schirmer test should be avoided in patients with blepharospasm because its results are influenced by frequent blinking and are not appropriate for study interpretation. Despite the pathologic values of TBUT test (numerically), this test is still acceptable for patients with blepharospasm because its interval takes more time than the interval between two blinks.