MMP13 and keratoconus: In the present study, our goals were to determine associations between the different types of mediators in tear fluid—IL-6, IL-10, chemokine (C-X-C motif) ligand 8 (CXCL8)/IL-8, CCL5/RANTES, MMP-9, MMP-13, TIMP-1, tissue plasminogen activator (t-PA), and plasminogen activator inhibitor (PAI-1)—in the whole spectrum of keratoconic eyes (suspect, subclinical, and manifest cases of keratoconus) and normal eyes.