Impact of the Different Corneal Storage Flasks on Endothelial Cell Loss During Cultivation—A Retrospective Analysis

<b>Objectives:</b> To evaluate the impact of different corneal storage containers-with and without corneal holders-on endothelial cell density (ECD) and endothelial cell loss (ECL) during organ culture, following a temporary shortage of Böhnke Donor Corneal Holders at a German eye bank. <b>Methods:</b> A retrospective analysis was conducted on 383 human donor corneas cultured in six types of containers between January and September 2024 at the Eye Bank of Rhineland-Palatinate. ECD was measured at 6.0 ± 1.2 days (ECD1) and again at 14.9 ± 4.4 days (ECD2) after retrieval using standardized organ culture protocols with an inverted light microscope. Group 1 (G1) used the standard 50 mL Corning^® flask with the Böhnke corneal holder. Groups 2-6 used alternative containers, with or without corneal holders. ECL was defined as the difference between ECD2 and ECD1. <b>Results:</b> Mean overall ECD1 was 2478.3 ± 843.4 cells/mm². G1 showed ECD1 < 2000 cells/mm² in 29% of corneas and low ECL (-1%). The 60 mL Ratiolab^® flask with Cornea-Claw^® was the best alternative, showing the lowest incidence of ECD1 < 2000 cells/mm² (7%) and no ECL. Containers without corneal holders, particularly the 100 mL Sterilin™ and 15 mL Cryogenic Tube^®, had significantly higher rates of ECD1 < 2000 (40% and 75%) and greater ECL (9% and 14%). <b>Conclusions:</b> Container design, especially volume and the presence of corneal holders, significantly influences endothelial preservation. Especially a lack of corneal holders led to unacceptable endothelial cell loss. Eye banks should prioritize appropriate flask configurations to minimize tissue deterioration, particularly during supply shortages.