Detection of connective tissue growth factor (CTGF) in human tear fluid: preliminary results

PURPOSE: Connective tissue growth factor (CTGF) is one of the main regulators of fibrosis. We aimed to evaluate its presence in the human tear fluid of healthy individuals. METHODS: A total of 70 tear fluid samples were collected from eight volunteers prior to and after stimulation of reflex tears with onion vapour. Specific ELISA analysis was performed with goat IgG against human CTGF. RESULTS: Connective tissue growth factor was detected in seven samples (10%), with maximum levels of 17 ng/mL in basal tears. Induction of reflex tearing resulted in a fast and significant decrease of CTGF concentrations (r = - 0.95). No CTGF was detected in 90% of the samples. CONCLUSION: Connective tissue growth factor may occur in tear fluid in healthy human eyes. This indicates a possible role for tear fluid CTGF in ocular surface fibrosis and wound healing.