Abstract

VICO, E et al. Tear function index validation for dry eye diagnosis. Arch Soc Esp Oftalmol [online]. 2004, vol.79, n.6, pp.265-271. ISSN 0365-6691.

Purpose: To develop a simple method for the clinical evaluation of tear dynamics and evaluate its usefulness in the diagnosis of dry eye syndrome. Methods: The study includes 170 eyes from 85 adults. 102 eyes had a Schirmer’s test value of less than 10 mm and subjective symptoms of dry eye. Tear function index (TFI) was calculated in all the cases using prepared drops with 0.5% fluorescein and 0.4% oxibuprocaína. Five minutes later a Schirmer strip was placed on the conjunctival fornix. Schirmer’s test and tear clearance were calculated after a further five minutes. Tear clearance was measured using a table of fluorescein concentrations. TFI is the quotient between the value of the Schirmer’s test and TCR. Results: The cutt-off value of TFI in dry eye is 74. At this point the sensitivity of this method is 74% and the specificity is 63%. The Schirmer’s test results did not correlate with the tear clearance results. Conclusion: TFI is a rapid and sensitive method of identification of subjects with dry eye. The lack of correlation between TFI and TCR is because these methods evaluate differents aspects of tear dynamics.

Keywords : Tear function index; dry eye; Schirmer test; tear clearance.