The Correlation of Routine Tear Function Tests and Conjunctival Impression Cytology in Dry Eye Syndrome

ABSTRACT

PURPOSE: To establish the strength of the association between routine tear function tests and conjunctival impression cytology (CIC) and to determine whether they simulate the morphological and cytological changes that occur on the ocular surface in dry eye. What are the sensitivity, specificity and positive predictive values of these tests when CIC is considered the gold standard? METHODS: The tear film profile included tear film break up time (TBUT), Schirmer's-1, Rose Bengal scores (RBS), and impression cytology. CIC samples were obtained from the inferior bulbar conjunctiva and stained with periodic acid-Schiff and counter stained with hematoxylin and eosin. RESULTS: The mean Schirmer's value was 11.66 +/- 5.90 in patients and 17.17 +/- 2.97 in controls (p Schirmer's > RBS, and the specificity was Schirmer's > TBUT > RBS in decreasing order when CIC was considered the gold standard.