TNF and dry eye syndrome: In the no dry eye group, the initial concentrations of IL-1β, IL-6, IL-8, MCP-1, TNF-α and IFN-γ were 2.11 ± 0.14, 13.36 ± 1.97, 143.83 ± 11.92, 55.49 ± 5.94, 9.04 ± 0.01 and 0.55 ± 0.19pg/ml, respectively.