Lacrimal function tests.

A comparative study of lacrimal function tests was undertaken. The primary Jones fluorescein test, the fluorescein dye disappearance (FDD) test, the Hornblass saccharin taste test and the Schirmer secretory test were tested for their reliability and effectiveness in 60 lacrimal systems with no known pathologic history or physical findings. Schirmer test values diminish with advancing age. The correlation between the FDD test, the Jones fluorescein test, and the saccharin taste test was low. The FDD test is an unsatisfactory test. The saccharin taste test time was shorter in patients with a positive Jones fluorescein test and longer in patients with a negative Jones fluorescein test. Forty-eight percent or 31/60 lacrimal systems had a negative Jones fluorescein test. This is higher than previously reported. The saccharin taste test was found to be the most practical and reliable of all lacrimal excretory function tests despite its subjectivity.