TNF and dry eye syndrome: Meanwhile, the correlation between the severity of dry eye and the level of inflammatory factors has been confirmed by a large number of studies, such as the work performed by Lam et al., who compared the concentrations of tear cytokines in ADDE and control patients, with the results indicating that IL-6, IL-8 and TNF-α were significantly higher, while in patients with MGD, IL-12 was significantly higher and IL-6 was positively correlated with irritation symptoms [84].