Easier, safer with eye bank prep and stamping
DMEK has changed in the ten years since it was first introduced, Dr. Terry continued.
Standardized techniques have improved the speed of the procedure, and some of these procedures have been published.4-7
There has also been improvement in the tissue that is received from eye banks. The tissue used for DMEK is delivered pre-stripped, removing the concern of destroying the tissue in the operating room. It is pre-stamped with an “S” mark on the Descemet’s side, not the endothelial side, eliminating the problem of upside-down grafts, which can be a primary cause of graft failure. Once the tissue is inside the chamber, before the gas or air bubble is added, the “S” verifies it is right side up.
Even more recently, the DMEK donor tissue can be supplied already “pre-loaded” into a Straiko glass injector, saving time, risk, and money for the operating surgeon.
Dr. Terry noted that the Devers Eye Institute has published a standardized technique for DMEK.7
The synthesis of techniques uses pre-stripped tissue from an eye bank, which has the “S” stamp provided. The surgeon overstrips the recipient, as recommended by Kruse6, to get better adhesion in the periphery. The institute uses a Straiko glass injector (Michael Straiko, MD) and a no-bubble-tap unfolding technique developed by Edfel Yoeruek many years ago.8
José L. Güell, MD, has advocated 20% SF6 bubbles 10, which do increase adhesion in the periphery through sustained support, but air may do just as well in most cases.
It is important to note that the DMEK procedure has evolved since its beginning.
The learning curve is now very fast, Dr. Terry said. Experienced DSAEK surgeons who are turning to DMEK procedures are experiencing much better outcomes in their first cases than earlier DMEK surgeons did.3
DMEK for endothelial failure
For routine cases of endothelial failure, DMEK has a better visual outcome for the patient and lower risk of rejection, Dr. Terry explained.
Patients can stop taking steroids in just a few months, and because fewer steroids are needed, the patient can be put on fluorometholone eye drops for the time they are on steroids very quickly, to avoid steroid complications.
The learning curve is easier and faster now than ever, and the eye bank is doing the tissue preparation--making surgery faster, easier, and safer, Dr. Terry noted.
Complication rates, even in a surgeon’s early cases, can be as low as DSAEK if an established technique is used.3,7