Deep anterior lamellar keratoplasty versus penetrating keratoplasty for treating keratoconus.

Background: Keratoconus is an ectatic (weakening) disease of the cornea, which is the clear surface at the front of the eye. Approximately 10% to 15% of patients diagnosed with keratoconus require corneal transplantation. This may be full-thickness (penetrating) or partial-thickness (lamellar).