*5.2.3 Corneal transplantation*

Treatment options for advanced keratoconus that has corneal thickness less than 400 μm, Kmax more than 58 D may be limited to corneal transplantation that can stabilize the cone and enable continued contact lens wear [86]. The keratoplasty techniques may be penetrating keratoplasty (PK), Deep Anterior Lamellar Keratoplasty (DALK) or Bowman layer transplantation.
