Tissue inhibitor of metalloproteinase 1 (TIMP-1) had an average expression level of 7,153.1±2,227.9 in the normal group, 15,579.0±8,213.9 in the KCGP group and 11,898.4±287.5 in the KC group (p=0.06). This evidence concerns the gene TIMP1 and keratoconus.