Patients with keratoconus who become contact lens intolerant or have significant corneal scarring may require a corneal transplant to regain visual function. The success rate of a full thickness transplant (penetrating keratoplasty-PK) is approximately 90%. However, patients who have had a PK have a life-long 10% risk of rejection and, in the case of keratoconus, may have recurrence of keratoconus years after the transplant. The photo to the left shows a patient with recurrent keratoconus after a PK who now successfully wears a scleral contact lens.