Preloaded DMEK, Safe Delivery as Easy as 1-2-3!

In a webinar hosted by Geuder AG in collaboration with the Veneto Eye Bank Foundation (Venice, Italy), leading experts in corneal surgery shared insights on the revolution of preloading Descemet membranes for endothelial keratoplasty (DMEK) in eye banks and how to increase safety and speed in DMEK procedures with ready-to-implant Descemet grafts. This webinar, held on November 12, was attended by about 130 eye specialists across the globe.

Redefining the DMEK procedure

In his welcome address, Dr. Diego Ponzin, medical director and corneal consultant at Veneto Eye Bank Foundation, said that DMEK is a procedure that can be defined as extraordinary in terms of adaptability and visual rehabilitation results.

“However, it can also be challenging, both intraoperatively and during patient follow-up. So for this reason, we regard, with much consideration, any initiative that is aimed at standardizing and improving, either the donor or implantation surgical procedures,” he noted.

“We are glad to work with Geuder, a company that has supported us in performing preclinical and clinical validation of their new tool, an innovative way to hold, transport and deliver the delicate tissue,” added Dr. Ponzin.

Dr. Mohit Parekh, research associate at the Institute of Ophthalmology, University College London (United Kingdom), has been working on DMEK for over a decade. During his lecture in the webinar, Dr. Parekh shared that he and his team started exploring preloaded DMEK devices about five years ago.¹

“From our research, we have discovered that the preloaded DMEK (both endo-in and endo-out) is easy to use, time-saving and hassle-free with clinical outcomes similar to surgeon-prepared DMEK grafts. Besides, both endo-in and endo-out procedures have shown similar clinical outcomes,”² he explained.

The preloaded DMEK: A journey in discovery

Further in the webinar, in his narrative of the essential milestones in the evolution of DMEK, Prof. Peter Szurman, head of Eye Clinic Sulzbach (KKSaar) in Germany, explained the history of preloaded DMEK.

Prof. Szurman has been a driving force in the development of DMEK techniques and devices, and together with Geuder, they are pioneers of the DMEK glass cartridge.³ Also, in cooperation with the DGFG (German Society for Tissue Transplantation), Prof. Szurman and Geuder are pioneers of DMEK RAPID, the first CE marked system for preloading, transportation, and injection of Descemet membranes.^4,5 Prof. Szurman’s goal is to always deliver an atraumatic transplantation with minimum endothelial cell loss and standardization of the complete procedure.

Getting the best out of DMEK RAPID preloaded

Essentially, 13 years of DMEK have led to DMEK RAPID preloaded in the same manner that intraocular lens (IOL) implantation has led to preloaded IOL injectors.

Today, the first eye banks have validated the system with positive results and are ready to utilize it.

In a laboratory proof-of-concept study, Rickmann, Wahl, Hofmann, et al. (team of investigators at DGFG) compared preloaded DMEK grafts with conventional precut grafts. Their findings conclude that DMEK grafts can be preloaded, stored and shipped for up to 2 days in dextran-containing medium without significant endothelial cell loss.⁴

At the webinar, in discussing the current status of DMEK RAPID preloaded validation studies, Dr. Gabriela Wojcik, research scientist at the Veneto Eye Bank Foundation, shared that they have initially performed a laboratory-based, four-day transport simulation in which they’ve compared tissue culture media with transport media.

“This study showed significant tissue preservation, shown by cell viability assays and morphology protection by the DMEK RAPID system after the four days,”⁶ she shared.

“In our on-going clinical study across five centers in Italy and the United Kingdom, we have preliminary results showing optimal graft safety based on phacometry and OCT imaging,” added Dr. Wojcik.

Promising preliminary data regarding the safety of transporting DMEK preloaded with the Geuder device cross country over 72 hours proved that surgeons received high quality and ready-to-use tissues.

Finally, having had extensive experience with the DMEK RAPID preloaded, Dr. Vincenzo Scorcia, professor of ophthalmology at the University of Magna Graecia (Catanzaro, Italy), shared useful tips for other surgeons.

“In using the DMEK-preloaded, we advise surgeons to carefully wash the transport liquid, and re-stain the graft if necessary. Also, check the mark, and accordingly rotate the injector. And then, inject slowly to prevent graft inversion,” shared Dr. Scorcia.

Lastly, he pointed out that surgery time is significantly reduced, because donor stripping and preparation as well as graft manipulation during loading is done by the eye bank. “With DMEK RAPID preloaded, the risk of tissue loss is virtually eliminated,” said Dr. Scorcia.

The future of DMEK RAPID

Based on preliminary study findings, surgeons can look forward to a future of fast, easy and safe delivery of Descemet membranes for DMEK from eye banks straight to the clinics. “More research and development is planned to further optimize DMEK procedures and related clinical outcomes,” said Geuder AG’s VP Sales & Marketing, Hamadi El-Ayari.

References:

1. Ruzza A, Parekh M, Ferrari S, et al. Preloaded donor corneal lenticules in a new validated 3D printed smart storage glide for Descemet stripping automated endothelial keratoplasty. Br J Ophthalmol. 2015;99(10):1388-1395.
2. Parekh M, Ruzza A, Ferrari S, et al. Endothelium‐in versus endothelium‐out for Descemet membrane endothelial keratoplasty graft preparation and implantation. Acta Ophthalmol. 2017;95(2):194-198.
3. Rickmann A, Wahl S, Katsen-Globa A, Szurman P. Safety analysis and results of a borosilicate glass cartridge for no-touch graft loading and injection in Descemet membrane endothelial keratoplasty. Int Ophthalmol. 2019;39(10):2295-2301.
4. Rickmann A, Wahl S, Hofmann N, et al. Comparison of preloaded grafts for Descemet membrane endothelial keratoplasty (DMEK) in a novel preloaded transport cartridge compared to conventional precut grafts. Cell Tissue Bank. 2020;21(2):205-213.
5. Rickmann A, Wahl S, Schulz A, Szurman P. Transport Comparison of Preloaded DMEK grafts. Cornea 2020; in press
6. Wojcik G, Parekh M, Romano V, et al. Preloaded Descemet Membrane Endothelial Keratoplasty Grafts With Endothelium Outward: A Cross-Country Validation Study of the DMEK Rapid Device. Cornea 2020 [Online ahead of print.]