COL5A1 and keratoconus: This might be associated to the fact that Col5a1+/ − corneas are globally and homogenously deficient in collagen V. In addition, unlike keratoconus corneas, which exhibit localized biomechanical weakening and corneal topographic changes, the higher elastic modulus found here in Col5a1+/− corneas support the counterintuitive findings in which collagen V-deficient corneas are able to maintain their physiological shape.