Evaluation of Keratoconus Disease with Tear Cytokine and Chemokine Levels Before and after Corneal Cross-Linking Treatment.

OBJECTIVES:To compare tear cytokine and chemokine levels of keratoconus (KC) patients with controls to perceive etiology distinctly and to clarify the molecular changes after cross-linking (CXL).METHODS:Tear samples were gathered from 34 participants in this prospective study. Participants underwent anterior and posterior segment examinations with slit-lamp biomicroscopy. Patients were assessed by corneal topography before and 3 months after CXL. Flat (K1), steep (K2), and average keratometry (Kmean), cylinder (CYL), and central corneal thickness (CCT) values were evaluated. After 3 months from CXL, samples were re-collected, and comparisons were made with preoperative values.RESULTS:Levels of IFN-gamma, IL-8, IL-12, IL-17, TNF-α, IL-4 and IL-13 were detected higher in KC patients (p= 0.008, p= 0.047, p= 0.001, p= 0.001, p= 0.001, p= 0.001, p= 0.027, respectively). After CXL IL-4, IL-5, IL-6, IL-7, IL-8, TNF-α levels showed significant decrease (p= 0.005, p= 0.045, p= 0.010, p= 0.022, p= 0.001, p=0.002, respectively). As for the topographic measurements, postoperative CCT values were increased whereas Kmean reduced after CXL (p < 0.001, p = 0.015, respectively). (p= 0.001, p= 0.027, respectively).CONCLUSION:Our findings imply that inflammation plays a key role in the development of KC and that this link is influenced by CXL therapy.