Immunostaining for Sp1 in corneas from a 61 year old normal individual and a 22 year old keratoconus patient, as well as a lenticule of a patient after epikeratoplasty for keratoconus (case 12). In both the lenticule and keratoconus corneas (positive controls), the nuclear immunolabelling was stronger in basal corneal epithelial cells, wing cells, and keratocytes than cells in the normal cornea (chromagen fast red TR/naphthol AS-MX phosphate). Image analysis confirmed significant differences in labelling intensity between normal control (epithelium: basal: 35.8 (SD 4); wing: 32 (4); stromal cell: 9 (3)) and epikeratoplasty (epithelium, basal: 64 (7) (p = 0.000008); wing: 59 (8) (p = 0.001); stromal cell: 82 (4) (p = 0.00001)), and keratoconus (epithelium: basal: 55 (4) (p = 0/001); wing: 55 (3) (p<0.00001); stromal cell: 81 (2) (p = <0.00001)).