Cornea Transplantation

Excerpt

Corneal disease ranks as the fifth leading cause of blindness in the world. Keratoplasty is the most common and successful transplantation in humans with the first transplant completed in 1905.

History of Corneal Transplantation

Modern corneal transplantation techniques represent the culmination of centuries of ideas, experimentation, and perseverance. The French surgeon Pellier de Quengsy was the first to suggest the use of a transparent material to replace an opaque cornea in 1789. Transplantation with xenografts was first postulated by Karl Himley in 1813 and attempted, experimentally and without success, by his student Franz Reisinger in 1824. Richard Kissam performed the first therapeutic corneal xenograft with a porcine cornea in 1838. The first successful human allograft and penetrating keratoplasty (PK) followed developments in anesthetics and antiseptic surgery and was performed by Eduard Zirm in December 1905 on a 45-year-old farm laborer with lime burns.

Recent Developments

Scientific advances in immunology, surgical technique, and tissue banking have shaped corneal transplantation into the field it is today. The last 20 years have brought significant developments in selective endothelial replacement that have brought about considerable shifts in the field.

Gerrit Melles described a posterior lamellar keratoplasty (PLK), whereby only a portion of the cornea was transplanted. Following an incision at the limbus, the endothelium, Descemet’s membrane (DM) and posterior stroma were dissected out and replaced by a donor button consisting of the same corneal layers that were held in place by an air bubble. Mark Terry modified the PLK in 2001, including the use of viscoelastic material instead of an air bubble and renamed the procedure deep lamellar endothelial keratoplasty (DLEK). In 2004 Gerrit Melles modified the technique further by only removing the host endothelium and DM (i.e., descemetorhexis), obviating the need for stromal dissection, and replacing with a donor button of endothelium, DM and stroma (Descemet’s stripping endothelial keratoplasty; DSEK) with further modification for automated donor dissection using a microtome (Descemet’s stripping automated endothelial keratoplasty; DSAEK). In 2006 the technique was further developed by only transplanting a donor button of endothelium and DM without the posterior stroma (Descemet’s membrane endothelial keratoplasty; DMEK). Minor modifications include automated posterior lamella dissection similar to DSEK (Descemet’s membrane automated endothelial keratoplasty; DMAEK).

A selective keratoplasty technique that relates to the anterior cornea is the deep anterior lamellar keratoplasty (DALK), whereby a donor button replaces the epithelium, Bowman's layer, and stroma.