SPRR3 and keratoconus: We observed in the early KC a significant decrease in the expression of KRT16, KRT14, SPRR1A, SPRR2A, SPRR3, TGM1 and TGM5 (fold change of 0.09, 0.31, 0.21, 0.11, 0.10, 0.27 and 0.14, respectively, P value of <0.0001, 0.044, 0.0022, <0.0001, 0.0006, <0.0001 and 0.009, respectively).