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

## TL;DR

This study found that using corneal storage flasks without corneal holders leads to significant endothelial cell loss in donor corneas during organ culture.

## Contribution

The study identifies optimal corneal storage containers with corneal holders to minimize endothelial cell loss during organ culture.

## Key findings

- Flasks with corneal holders, like the 60 mL Ratiolab® with Cornea-Claw®, showed minimal endothelial cell loss.
- Containers without corneal holders, such as the 100 mL Sterilin™ and 15 mL Cryogenic Tube®, caused significant endothelial cell loss.
- The presence of corneal holders and appropriate flask volume significantly influences endothelial preservation.

## Abstract

Objectives: 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. Methods: 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. Results: 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%). Conclusions: 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.