Authors (including presenting author) :
Chow Y(1), Leung KP(1), To W(1), Chow WS(1)(2), Wong SM(1), Lai KH(1), Ting MY(1), Liu CH(1), Hung CS(1)
Affiliation :
(1)Hospital Authority Eye Bank (2)Hong Kong Eye Hospital
Introduction :
Hospital Authority Eye Bank (HAEB) has provided lamellar graft preparation in Hong Kong (HK) since 2008. Constantly motivated to promote conservation of corneal tissue and provide thinner grafts for surgeons and patients, HAEB initiated to develop the technique of Descemet’s Membrane Endothelial Keratoplasty (DMEK) graft preparation in September 2020. A year later, HAEB started to provide pre-stripped and pre-stamped DMEK grafts for clinical use.
Objectives :
To establish the procedures for DMEK graft preparation in HK
Methodology :
From September 2020 to May 2021, 33 pieces of local and 26 pieces of imported training corneas were used for the development of the pre-stripping and pre-stamping techniques. From October 2021, 6 more pieces of pre-stripped DMEK graft with pre-stamp were prepared for clinical use. The medical history of the donors, endothelial cell loss (ECL) of the grafts, status of the stamp mark and success rate of DMEK stripping were analysed. The process of the development of pre-stripped and pre-stamped DMEK grafts in a regional eye bank will also be discussed.
Result & Outcome :
The success rate of DMEK stripping was 81.8% (27/33) for local training corneas and 88.5% (23/26) for imported training corneas. After studying the parameters from the training corneas, donors with diabetes mellitus (DM) had a higher rate of failure: 62.5% (5/8) vs 7.8% (4/51) in donors with non-DM (p=0.000), average ECL was 5.02±7.82%, and 100% of the grafts had pre-stamp evident by day-3 after using the designated marker pen. The pre-stripped and pre-stamped training corneas were further used in several DMEK workshops for local corneal surgeons to practise DMEK transplantation in a wetlab setting. Discussion with surgeons during the workshops also helped lay the foundation for the current request and dispatch guidelines. Since October 2021, 6 requests for DMEK graft preparation have been received with a stripping success rate of 100%, pre-stamp still evident on the day of surgery in 100%, and average ECL of 0.41±2.45%. As an internationally accredited eye bank, HAEB developed and prepared pre-stripped and pre-stamped DMEK grafts in accordance with international standards. Success rate in stripping, ECL and quality of the pre-stamp were all comparable to those published in the literature. In the coming future, HAEB technicians will continue advancing the techniques, including introduction of the “air-bubble pre-stamping" technique to circumvent punching a stromal hole such that one graft may be used in two patients, and providing preloaded DMEK grafts to further assist surgeons in performing the DMEK transplantation.
