Tear osmolarity in the diagnosis and management of XXXX .

@entity2194 @entity6724 @entity936
PURPOSE: To evaluate the use of tear osmolarity in the diagnosis of @entity2194 . DESIGN: A prospective, observational case series to determine the clinical usefulness of tear osmolarity and commonly used objective tests to diagnose @entity2194 . METHODS: A multicenter, 10-site study consisting of 314 consecutive subjects between 18 and 82 years of age. Bilateral tear osmolarity, @entity6724 ( @entity6724 ), corneal staining, conjunctival staining, Schirmer test, and meibomian gland grading were performed. Diagnostic performance was measured against a composite index of objective measurements that classified subjects as having normal, mild or moderate, or severe @entity936 . The main outcome measures were sensitivity, specificity, area under the receiver operating characteristic curve, and intereye variability. RESULTS: Of the 6 tests, tear osmolarity was found to have superior diagnostic performance. The most sensitive threshold between normal and mild or moderate subjects was found to be 308 mOsms/L, whereas the most specific was found at 315 mOsms/L. At a cutoff of 312 mOsms/L, tear hyperosmolarity exhibited 73% sensitivity and 92% specificity. By contrast, the other common tests exhibited either poor sensitivity (corneal staining, 54%; conjunctival staining, 60%; meibomian gland grading, 61%) or poor specificity ( @entity6724 , 45%; Schirmer test, 51%). Tear osmolarity also had the highest area under the receiver operating characteristic curve (0.89). Intereye differences in osmolarity were found to correlate with increasing disease severity (r(2) = 0.32). CONCLUSIONS: Tear osmolarity is the best single metric both to diagnose and classify @entity2194 . Intereye variability is a characteristic of @entity936 not seen in normal subjects.
