Double port injector device to reduce endothelial damage in DMEK

Abstract

Objective To study endothelial injury from a newly designed asymmetric double port Descemet Membrane Endothelial Keratoplasty (DMEK) injector, both ex-vivo and in clinical practice. Design Laboratory investigation with an interventional case series study. Method Sixteen rabbit endothelial rolls were tested for injection using a no-touch technique. For each pair of rolls, one endothelial graft underwent injection with a single port Pasteur pipette twice, wheras the other was injected with a novel asymmetric double port injector with a larger diameter entry port than the exit port also twice. Each graft was stained with 4-6-diamidino-2-phenylinidole dihydrochloride and was counted under a fluorescence-inverted microscope before and after injection. The proportion of graft injury was calculated and the differences were analyzed. Subsequently, six patients requiring DMEK underwent surgery using this novel insertion device and endothelial cell loss was calculated 3 months after the surgery. Results After injection, the mean proportion of endothelial cell survival with the single port pipette was 78.8% (n ¼ 8; SD: ± 20.9%), whereas the double port injector yielded a survival rate of 96.8% (n ¼ 8; SD: ±8.4%). This difference was statistically significant (P ¼ 0.008), representing less endothelial injury with the double port device. Early endothelial cell loss after 3 months in the DMEK patients was 26.1% (SD: ± 6.1%). Conclusion In our injection model, using a double port injector created significantly less endothelial cell damage than with the single port pipette. Clinically, this device yielded early endothelial cell loss comparable to that of the series performed by experienced DMEK surgeons.

Impact of the radius of the injector system on the cell viability in descemet membrane endothelial keratoplasty: an ex vivo experimental study

“…Arnalich‐Montiel et al. () developed a double port injector system for reducing endothelial damage during the process of injection. A limiting factor of the current study may be the small sample size.…”

“…Different types of implantation systems have been described, some of which are now commercially available (Arnalich‐Montiel et al. ; Kim et al. ).…”

“…The graft typically presents the endothelial cells outwards, so that the correct implantation in the anterior chamber can avoid unnecessary intraocular manoeuvres. Different types of implantation systems have been described, some of which are now commercially available (Arnalich-Montiel et al 2014;Kim et al 2014).…”

Comparing the effect of three Descemet membrane endothelial keratoplasty injectors on endothelial damage of grafts

“…Different studies have proposed various injector techniques and expanded injector options. [ 2 7 8 9 10 11 12 ] One of the earliest injectors employed was the glass Pasteur pipette. In the USA today, commonly used injectors include the modified Jones tube, IOL injectors, and most recently, the Geuder glass cannula.…”

“…Descemet membrane endothelial keratoplasty (DMEK) has increased in popularity in recent years, largely due to rapid postoperative visual rehabilitation and excellent visual outcomes[ 1 2 3 4 5 6 ] since its advent, numerous techniques and injection methods have been described. [ 7 8 9 10 11 12 ] Commonly used injectors include the modified Jones tube (Gunther Weiss Scientific Glass, Portland, Oregon) and the STAAR intraocular lens (IOL) injectors, which are The Food and Drug Administration (FDA)-approved in the United States and used off-label for DMEK.…”