A new era in corneal transplantation: paradigm shift and evolution of techniques.

Penetrating keratoplasty is the replacement of a diseased cornea with a full-thickness donor graft. In the last century, this 'gold standard' procedure was long established as the treatment of choice for various corneal diseases. The classical indications for a penetrating keratoplasty entailed optical, tectonic, therapeutic, and cosmetic issues. Over the past decade however, surgical advances have now enabled operations involving the cornea to be performed with a major shift in emphasis, such that penetrating keratoplasty has given way to lamellar (layered) keratoplasty. This review provides the latest updates on developments in the field of corneal transplantation and the nomenclature of different types of component surgery, particularly from the perspective of Hong Kong.