Lysozyme content of tears in patients with Sjögren's syndrome and rheumatoid arthritis.

In 37 patients and 143 control patients we estimated tear fluid lysozyme content by the Micrococcus lysodeikticus agar diffusion assay. We found no correlation between the titer of lysozyme in tear fluid and the rate of tear flow. Decrease in lysozyme production was found to be a sensitive indicator of the involvement of the lacrimal system in Sjögren's syndrome.