Anterior / Ocular Surface Disease

Tear Function Index

The tear function index uses prepared filter paper strips containing fluorescein. Similar to a Schirmer's test, the coated tear strip is left in the lid margin for three minutes. Then, the distance of moistened paper is measured and the color intensity of the fluorescein bleed in compared to the TCR scale. The tear function index is the quotient between the Schirmer value and TCR.