Use of deep anterior lamellar keratoplasty (DALK) for keratoconus: indications, techniques and outcomes

Introduction: Transplantation of all corneal layers, through penetrating keratoplasty (PK), is becoming less frequent as surgeons increasingly favor selective keratoplasty that selectively replaces diseased tissue. Deep anterior lamellar keratoplasty (DALK) which is used for corneal diseases not involving the endothelium, especially keratoconus, retains the advantages of both full-thickness and lamellar keratoplasty and avoids the disadvantages of the interface created during conventional lamellar keratoplasty. Since the introduction of DALK, many surgeons have adopted surgical modifications to increase its success rate and improve the clinical outcomes, necessitating an update on this technique of corneal transplantation. Areas covered: This article aimed to review the indications, different surgical techniques, clinical outcomes and complications following DALK. A review of the literature was performed using the keywords 'deep anterior lamellar keratoplasty' and 'DALK' in PubMed and reviewing all English articles including these keywords. Expert commentary: With growing surgeon experience and modifications in techniques, DALK appears to be a suitable substitute for PK in keratoconus as it eliminates endothelial graft rejection, preserves globe integrity, and requires less stringent criteria for donor tissue selection. These advantages by far overweigh the relatively challenging surgical technique and the long learning curve compared with PK.