Tear fluid proteins in Sjögren's syndrome.

Schirmer-I test, rose bengal staining and BUT in normals, keratoconjunctivitis sicca patients and patients with Sjögren's syndrome were compared with the results of lactoferrin, lysozyme and tear-specific prealbumin assays as diagnostic procedures for lacrimal gland function. The results suggest that all three major tear proteins, originating from the tear gland can serve as sensitive markers for lacrimal gland function. In clinical practice the simple immunodiffusion assay for lactoferrin could be a reliable alternative for the traditional diagnostic tests.