Relationship between tear eotaxin-2 and MMP-9 with ocular allergy and corneal topography in keratoconus patients

Purpose To analyze the relationship between the seasonal allergic conjunctivitis (SAC), eotaxin-2, matrix metalloproteinase-9 (MMP-9), and the topographical findings in the keratoconus patients. Methods Thirty-four eyes of patients without SAC (Group 1), 34 eyes of patients with SAC (Group 2), and 20 eyes of control subjects (control group) were enrolled. Tear samples of the subjects were collected by Schirmer method. Corneal topography parameters, tear MMP-9, and tear eotaxin-2 levels were analyzed. Results The mean tear MMP-9 levels in Groups 1 and 2 were significantly higher than in the control group ( p = 0.004). MMP-9 level exhibited a positive correlation with the keratoconus stage and a negative correlation with the thinnest corneal thickness ( r = 0.294, p = 0.018, and r = − 0.302, p = 0.006, respectively). The tear eotaxin-2 level was higher in Group 2 than in Group 1 and control group which is not statistically significant ( p = 0.17). Conclusion The tear eotaxin-2 did not exhibit any difference in the presence of keratoconus. The tear MMP-9 level was higher in the keratoconic eyes, and it showed a correlation with the stage of the disease and the corneal thickness.