Historical Development of Endothelial Keratoplasty

Introduction

During the 20th century, replacement of the endothelial layer for patients suffering from corneal edema was accomplished by performing a full-thickness penetrating keratoplasty (PK). This anatomically nonselective method provided a clear corneal window for vision but required corneal sutures to close the fragile, vertical wound of trephination. Despite months and years of healing, PK often left the patient with distortions due to irregular, high astigmatism and an inherently unstable wound with the increased long-term liability of globe rupture from minor trauma.

The introduction of endothelial keratoplasty (EK) ushered in a paradigm shift in the approach to endothelial replacement surgery. Over a short period of 20 years, the partnership of surgeons and eye bank professionals would allow pure anatomic replacement procedures that yielded dramatically faster wound healing, a near normal tectonic strength globe, reduced graft rejection rates, and an unprecedented quality of vision for transplant patients. This is a history of the people and events that have made EK the dominant surgical treatment for corneal edema ( Table 127.1 , Fig. 127.1 ).

Early Posterior Lamellar Keratoplasty

Jose Barraquer first described a method of selectively replacing diseased endothelium in his surgical drawings. In his description, a square anterior corneal flap was created, a circular trephine was used to excise the posterior tissues, the donor posterior tissue was placed, and then the flap was sutured into place. There is no record that Barraquer ever performed this procedure. The first clinical report of posterior lamellar keratoplasty (PLK) was in 1956 by Charles Tillett of Charlotte, North Carolina. Dr. Tillett similarly created a flap using a 180-degree limbal incision and anterior stromal dissection. The posterior stromal tissue was trephinated, replaced with a similar-sized donor tissue sutured in place, and then the overlying flap was also sutured. Amazingly, this delicate microsurgery was performed without the benefit of a surgical microscope. Tillett only reported one clinical case, and it successfully cleared the edema of the overlying recipient cornea; however, the patient subsequently lost all vision due to glaucoma.

The Flap Technique of Posterior Lamellar Keratoplasty

Nearly 40 years after Charles Tillett’s report, clinical work on PLK began anew. The microkeratome was now a familiar tool for corneal surgeons doing LASIK surgery and was adopted for creating the anterior flap of PLK. Now with faster, easier, and more precise surgery than what Barraquer and Tillett had ever imagined, surgeons developing this flap technique of PLK renamed it. Buddy Culbertson from Miami, Florida, called this surgery “endothelial lamellar keratoplasty” (ELK), Dimitri Azar of Boston called it “microkeratome assisted posterior keratoplasty,” Jose Guell of Barcelona retained the name as “posterior lamellar keratoplasty” and Massimo Busin of Italy called it “endokeratoplasty” (EKP). Despite the efforts of these and other talented surgeons, the flap technique of PLK required corneal sutures and trephinated wounds. These inherent factors plagued the flap technique with postoperative problems of irregular astigmatism and wound leaks. Although initially defended in later debates as superior to the early precursers of modern EK, the flap technique was ultimately abandoned due to poor results.