Endothelial keratoplasty presents challenges, opportunities

Issue: May 2015

SAN DIEGO — Despite various challenges, endothelial keratoplasty continues to evolve and gain favor among cornea surgeons, a speaker told colleagues here.

Perspective from Francis W. Price Jr., MD

Donald H. Tan, FRCS, FRCOphth, outlined the evolution of lamellar EK techniques in his delivery of the Binkhorst Lecture during opening ceremonies at the American Society of Cataract and Refractive Surgery meeting.

Donald H. Tan

“The field of cornea transplantation is rapidly evolving with a revolution of selective lamellar keratoplasty,” Tan said.“This certainly has to be the future. Endothelial keratoplasty today is the gold standard but surgical techniques and results need to improve. The evolution of EK will hopefully show better survival of endothelial cells and better long-term outcomes.”

EK has supplanted penetrating keratoplasty in the last decade. Currently, EK comprises 56% of all corneal transplantation procedures performed in the U.S., Tan said.

Descemet’s stripping endothelial keratoplasty (DSEK) and Descemet’s stripping automated endothelial keratoplasty (DSAEK) have a lower rate of endothelial cell loss and a higher rate of graft survival than PK, Tan said.

Descemet’s membrane endothelial keratoplasty (DMEK) “is the next big thing,” Tan said. “DMEK is anatomically the most perfect EK procedure but it still remains the most challenging. It’s relatively low-tech if you think about it.”

Currently DMEK represents 6% of all corneal transplants and 10% of EK surgeries in the U.S., Tan said.

“Unfortunately, there’s probably still more donor tissue wastage, more cell loss and a higher re-bubbling rate. I think we’re still at the evolutionary stage of DMEK. Will it ever become mainstream?” he asked. “It’s difficult to unscroll in the anterior chamber. One solution, perhaps, is to minimize handling.”

A more recent iteration of EK, deep anterior lamellar keratoplasty (DALK) is “still a little bit more art than science,” Tan said.

“It’s not easy and this is the problem: There is not a short learning curve. The problem is we have almost no technology . . . And the economics and the reimbursement for DALK, which is such a long procedure, just doesn’t make sense,” he said. – by Matt Hasson

Disclosure: Tan reports he has received research funding from Alcon, Allergan, Bausch + Lomb, Carl Zeiss Meditec, Network Medical Products and Santen.

Perspective

Francis W. Price Jr., MD

The Binkhorst Lecture honors those whose careers have made significant contributions to the science and practice of ophthalmology, so it was fitting that this year’s honoree was Donald T.H. Tan, FRCS, FRCOphth. Dr. Tan has a passion for many areas of ophthalmology, from refractive surgery to complex reconstructive surgery like the osteo-odonto keratoprosthesis. However, he has especially made an impact on lamellar corneal surgery and gave his views on where we are today with both endothelial keratoplasty and deep anterior lamellar keratoplasty. Because of his work, Singapore probably has the lowest percentage of penetrating keratoplasty and highest adoption of both EK and DALK of any country in the world.

Like most corneal surgeons, he has not yet made the full leap into doing DMEK, rightfully noting, “DMEK is anatomically the most perfect EK procedure, but it still remains the most challenging.”

I was surprised that he said, “DALK is still a little bit more art than science,” as he routinely preforms DALK and has published extensively on its merits over penetrating keratoplasties for both active infections and chronic conditions like keratoconus. Perhaps in deference to the U.S. audience, he noted that the economics of DALK do not make sense for the time it takes relative to the reimbursement.

Francis W. Price Jr., MD

OSN Cornea/External Disease Board Member

Disclosures: Price reports no relevant financial disclosures.