Tear absorption into the filter-paper strip used in the Schirmer-I-test. A methodological study and a critical survey.

The absorption of tear fluid into the Schirmer-I-filter paper was evaluated by serial measurements in 5 normal volunteers and in 32 patients with Sjögren's syndrome. The length of wetting was correlated to the weight of tear fluid absorbed in the paper strips. A linear relationship was demonstrated. We conclude that the Schirmer-I-test implies reproducible and fairly precise estimation of the tear flow even in cases of small lengths of wetting. The test is reliable, simple and useful for the diagnosis and follow-up of dry eyes, especially in patients with Sjögrens syndrome.