[Microkeratome-assisted anterior lamellar keratoplasty for the removal of corneal scar, caused by pterygium]

Component corneal surgery: An update

Several decades ago, penetrating keratoplasty was a challenge to corneal surgeons. Constant effort by the corneal surgeon to improve the outcomes as well as utilization of the available resources has led to a revolutionary change in the field of keratoplasty. All these efforts have led to the evolution of techniques that allow a corneal surgeon to disease-specific transplant of individual layers of corneal “so-called component corneal surgery” depending on the layer of cornea affected. This has led to an improvement in corneal graft survival as well as a better utilization of corneal tissues. This article reviews the currently available literature on component corneal surgeries and provides an update on the available techniques.

New perspectives on lamellar keratoplasty

Lamellar (anterior and posterior) keratoplasty entails the surgical replacement of diseased-only corneal tissue, while healthy host corneal tissue is preserved. Selective keratoplasty offers several advantages in comparison to penetrating keratoplasty such as a lower rate of graft rejection, less endothelial cell loss, faster/superior visual rehabilitation and enhanced resistance to closed injury. The surgical approach of "partial corneal transplantation" may be divided into anterior and posterior: techniques including superficial and deep anterior lamellar keratoplasty (SALK and DALK, respectively) and endothelial keratoplasty as well as Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK). These novel surgical procedures are rapidly becoming the preferred therapy option for specific corneal dysfunctions involving the corneal stroma (SALK, DALK), or corneal endothelium (DSAEK, DMEK). During the past decade, the continuing advancement of surgical techniques and the development of innovative surgical instruments have significantly enhanced corneal transplantation. Lamellar keratoplasty techniques facilitate corneal surgery, provide patients with superior outcomes and can successfully restore vision in corneal-related blindness. Nevertheless, more long-term evidence is needed to better evaluate these promising new techniques.