Figure 3. The correlation between each of the cytokines in tears and the symptom scores among all subjects. A high positive correlation was found between IL-1 β, IL-2, IL-6, and TNF- α and OSDI scores. A similar correlation was also found between these cytokines and NPSI-E scores. IL-17, IFN- γ, and IL-10 had very low and nonsignificant correlations with both OSDI and NPSI-E scores.