Analysis of tear inflammatory molecules and clinical correlations in evaporative dry eye disease caused by meibomian gland dysfunction

Purpose To compare the levels of inflammatory molecules in tear samples between patients with meibomian gland dysfunction (MGD)-related evaporative dry eye (EDE) and healthy subjects and to analyze the correlations between the levels of tear inflammatory molecules and ocular surface parameters. Methods A total of 30 MGD-related EDE patients (48 eyes) and ten healthy volunteers (15 eyes) were enrolled. Dry eye-related examinations and questionnaires were obtained from all participants. The levels of nine inflammatory molecules were determined through multiplex bead analysis. Results Inflammatory molecules including ICAM-1, IFN-gamma, CXCL8/IL-8, IL-6, TNF-alpha and IL-12p70 were detected in 100% of the patients, while IL-1 alpha, IL-1 beta and IL-10 were detected in 56.25%, 13.60% and 45.83% of the patients, respectively. Moreover, ICAM-1, IL-8, IL-6, TNF-alpha, IL-12p70 and IFN-gamma were detected in 86.67-100% of the healthy subjects, and the detection rates of IL-10, IL-1 alpha and IL-1 beta were below 50%. The levels of IL-8, IL-6, IFN-gamma and ICAM-1 were significantly higher in the patient group compared with the control group. In addition, IL-8 and IL-6 were negatively correlated with Schirmer I test. Besides, IFN-gamma was negatively correlated with tear film breakup time. Furthermore, ICAM-1 and IL-6 were positively correlated with meibography score. Conclusions Collectively, patients with MGD-related EDE had higher levels of inflammatory molecules in their tears, and some molecules were correlated with ocular surface parameters. These findings suggested that inflammation played an important role in MGD-related EDE, and several inflammatory molecules could be used in the diagnosis and the treatment of MGD-related EDE.