Figure 3. Upregulation of tear cytokine concentrations in patients with dry eye. A: Tear concentrations of interleukin (IL)-33 showed statistically significant upregulation in the DE group compared with controls (3.00-fold upregulation, **p≤0.01, Kruskal–Wallis test, 21 and 17 samples in DE and controls respectively). B: Tear concentrations of IL-13 showed statistically significant upregulation in the DE group compared with controls (6.65-fold upregulation, **** p≤0.0001, Kruskal–Wallis test, 21 and 17 samples in DE and controls respectively). C: Tear concentrations of IL-5 showed statistically significant upregulation in the DE group compared with controls (16.54 -fold upregulation, p=0.01, Kruskal–Wallis test, 21 and 17 samples in DE and controls respectively). DE, dry eye.