Keratomileusis, keratophakia and keratokyphosis.

Using cryo-refractive corneal surgery, it is not yet possible to attain a post-operative visual acuity corresponding to that achieved with a contact lens. This is due to the tissue changes caused by the cryoprocess as well as to the interlamellar corneal scar. A description is given of keratokyphosis, a procedure by means of which the outer radius of the cornea can be altered without having to freeze the corneal stroma. The principle of the surgical technique consists of the removal of centrally thinned corneal discs from the patient's eye using a newly developed microkeratome. Subsequent suturing in of a donor corneal lamella leads to a protrusion of the corneal surface and thus to an alteration of the refractive power.