**1. Introduction**

Keratoplasty is considered the most successful organ transplantation procedure in the world. Reisinger was the first to use the term keratoplasty (Reisinger, 1824), when he suggested using an animal's eye to provide donor corneal tissue for corneal transplantation in a human. In 1906, the first successful penetrating keratoplasty was performed by Edward Konrad Zirm on a patient suffering from bilateral alkali burns (Zirm, 1906). Ramon Castroviego created some fine instruments that were named after him and was the first to perform successful penetrating keratoplasty using fine sutures (Castroviejo, 1932). His square-shaped grafts survived for many years and provided good vision for his patients.

In 1886, Von Hipple erformed lamellar corneal transplantation (Von Hipple, 1888). The concept of deep lamellar corneal dissection and leaving the Descemet membrane (DM) intact was first proposed by Von Walther and was described further by Muhlbauer (Muhlbauer, 1824). A full-thickness donor corneal tissue without any dissection through the corneal stromal tissue was proposed for lamellar keratoplasty in 1959 (Hallermann, 1963). Hallermann proposed both full-thickness donor graft with the endothelium (FTDGE) and full-thickness donor graft without the endothelium (FTDG) over a deeply dissected corneal stromal recipient's bed for lamellar keratoplasty. Morrison and Swan provided histopathologic evidence that FTDG is associated with less inflammation and scarring than FTDGE (Morrison & Swan, 1982).

Today, removing the corneal stromal tissues down to the DM or the pre-Descemet membrane level and using a FTDG is the standard of care for patients requiring deep anterior lamellar keratoplasty (DALK) surgery. Many techniques have been developed for performing DALK surgery. Before reviewing some surgical techniques for the procedure, I will discuss some factors that influence the visual outcomes.
