The results of this study demonstrate that subjects with confirmed Sjogren’s syndrome have increased levels of soluble MUC1 in their tear film and MUC1 mRNA in their conjunctival epithelial cells compared to both KCS and non dry eye (NDE) subjects and that SS subjects have increased levels of membrane bound MUC1 compared to NDE subjects. Here, MUC1 is linked to Keratoconjunctivitis sicca.