Corneal transplantation refers to surgical replacement of a full-thickness host cornea (penetrating keratoplasty [PK]) or lamellar portion of the host cornea with that of a donor cornea. Ongoing innovations in lamellar transplantation have produced a virtual alphabet soup of nomenclature to describe the various approaches (Table 15-1). If the donor is another person, the tissue is called an allograft and the procedure is referred to as allogeneic transplantation. If the donor tissue is from the same or fellow eye, it is called an autograft and the procedure is referred to as autologous transplantation (see the section Corneal Autograft Procedures, later in the chapter).
A 2015 review by Park et al of corneal transplant procedures (keratoplasty) performed over the past 10 years in the United States identified several trends. The number of transplants performed annually increased slightly from 2005 to 2014 (but peaked in 2008). However, there has been a dramatic shift in the types of procedures performed. The percentage of all transplants that were PK procedures decreased from 94.9% in 2005 to 41.5% in 2014. The percentage that were anterior lamellar keratoplasty (ALK) procedures (including DALK) increased slightly, but even by 2014, accounted for only 2.0% of total transplants. Most significantly, the percentage of all transplants that were EK procedures increased from 3.2% in 2005 to 55.9% in 2014; in the latter year, 49.7% were Descemet stripping endothelial keratoplasty (DSEK) and 6.2% were Descemet membrane endothelial keratoplasty (DMEK). The percentage that were keratoprosthesis procedures remained fairly stable at 0.6% of total transplants annually.
Table 15-1 Contemporary Keratectomy and Keratoplasty Procedures
Table 15-2 lists the indications for transplantation of corneal tissue from US eye banks for procedures performed in the United States and internationally in 2016. The success of any transplant depends on the availability and quality of corneal tissue. The cornea surgeon is thus indebted to the Eye Bank Association of America and to the outstanding US and international eye banks that provide tissue.
Park CY, Lee JK, Gore PK, Lim CY, Chuck RS. Keratoplasty in the United States: a 10-year review from 2005 through 2014. Ophthalmology. 2015;122(12):2432–2442.
Table 15-2 Indications for Transplant in US and International Eye Banks, 2016
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.