Introduction: In the nationwide network of the German Society for Tissue Transplantation (DGFG), currently more than 5000 cornea donations are performed annually. From donor notification to the retrieval of the tissue and its subsequent processing, various conditions must be fulfilled in accordance with legal regulations. According to the European guidelines a period of 72 hours is allowed for the entire process, the so-called death to preservation time (DPT). This time span is relevant due to the opt-in regulation in Germany. Since time could have an influence on the quality of the tissue, it must be ensured that the cornea released for transplantation is not affected by the time factor because safety of the recipients of a tissue transplant is paramount.

Method: In order to obtain information on this, the numbers of tissue donations in the network of the DGFG were evaluated as a function of the death to retrieval time (DRT) as well as the death to preservation time (DPT). For this purpose, 21,454 database entries of cornea donations made in the period from 2014 to 2018 were included.

Results: The analysis of more than 20,000 corneal donation records over a 5-year period showed that the majority of cornea can be retrieved within 36 hours and 50% of the tissue is processed in the tissue bank between 48 and 72 hours (DPT). The transplantation rate (TX-rate), namely the number of corneas that were allocated for transplantation, revealed that the quality parameters required for release were met in 65% of the corneas which is comparable to average TX-rates stated in literature.

However, for corneas that had a longer DPT interval a slightly increased discard rate appeared. Moreover, a multiple regression analysis showed that donor age has a far greater influence on the most important quality parameter, the endothelial cell density, than DPT [1].

Conclusion: From our analysis it can be concluded that the time span of up to 72 hours DPT for corneal tissue has no influence on the quality of corneas that are ultimately transplanted since all corneas approved for transplantation must meet specified quality parameters independent from the death to preservation time.

Reference
[1] Hofmann N, Wittmershaus I, Salz AK, Börgel M. Cornea Procurement and Processing up to 72 Hours: No Risk for Cornea Transplant Quality. Transfus Med Hemother. 2021 Feb;48(1):3-11.