title: Association between mediators in the tear fluid and the severity of keratoconus.
abstract: OBJECTIVE
  To study the association between different types of mediators in the tear fluid and topographic indices characterizing the severity of keratoconus (KC).
  
  
  METHODS
  In this study, nonstimulated tear fluid samples were collected from 14 eyes of 11 patients with KC. The following indices were measured by corneal topography: maximum K value, average K value, Klyce/Maeda keratoconus index (KCI), Smolek/Klyce keratoconus severity index, opposite sector index, center/surround index, keratoconus prediction index and standard deviation of corneal power. The concentrations of interleukin (IL)-6, IL-13, CXCL8 (IL-8), chemokine (C-C motif) ligand 5 (CCL5, regulated and normal T cell expressed and secreted), matrix metalloproteinase-9 (MMP-9), MMP-13, tissue inhibitor of metalloproteinase-1, nerve growth factor (NGF) and epidermal growth factor were measured by cytometric bead array technology. Release of mediators was calculated from their concentrations and the volume of tears collected over 2 min.
  
  
  RESULTS
  Significant positive associations were found between CCL5, MMP-13 and NGF and several topographic indices. Significant negative correlations were found between IL-6 and KCI. Age-dependent associations were observed between IL-13, CXCL8, CCL5 and MMP-13 and the topographic data.
  
  
  CONCLUSIONS
  Several correlations were observed between the mediators and the topographic indices, suggesting possible roles in the pathophysiology of KC. Our data indicate that some mediators have different effects on the severity of disease in an age-dependent manner.
authors.affiliation: Department of Ophthalmology, University of Debrecen, Debrecen, Hungary.
authors.forename: Bence Lajos
authors.initials: BL
authors.lastname: Kolozsvári
authors.forename: Goran
authors.initials: G
authors.lastname: Petrovski
authors.forename: Péter
authors.initials: P
authors.lastname: Gogolák
authors.forename: Éva
authors.initials: É
authors.lastname: Rajnavölgyi
authors.forename: Flóra
authors.initials: F
authors.lastname: Tóth
authors.forename: András
authors.initials: A
authors.lastname: Berta
authors.forename: Mariann
authors.initials: M
authors.lastname: Fodor
mesh_terms: D000328:Adult; D019781:Corneal Topography; D016207:Cytokines / Q000032:analysis; D005136:Eye Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis; D007640:Keratoconus / Q000378:metabolism*; D008297:Male; D020782:Matrix Metalloproteinases / Q000032:analysis*; D008875:Middle Aged; D012044:Regression Analysis; D012720:Severity of Illness Index; D013666:Tears / Q000737:chemistry*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis; D055815:Young Adult
chemical_list: D016207:Cytokines; D005136:Eye Proteins; D036341:Intercellular Signaling Peptides and Proteins; D019715:Tissue Inhibitor of Metalloproteinase-1; C042434:tear proteins; D020782:Matrix Metalloproteinases