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French corneal banks have been forced in 2024 to substitute EUROBIO° media, which do not have CE marking, by ALCHIMIA° media.Purpose To compare ALCHIMIA° and EUROBIO° media (Endothelial cells density: ECD, microbiological contamination rate)Methods This retrospective study focuses on X corneal grafts (CG) collected with EUROBIO° media and X with ALCHIMIA° media. CG were transported at room temperature for approximately 2 days and then stored at 31°C. For EUROBIO°, CG is transported in CorneaPrep° medium (320 ± 20 mOsm/kg, penicillin, streptomycin), then at D6 transferred to CorneaMax° medium. For ALCHIMIA°: transport and storage in TissueC° (300 ± 45 mOsm/kg, penicillin, streptomycin, amphotericin B). Samples for sterility test are taken at D5 for CorneaPrep° or at D2-D5 for TissueC°. The sterility test is performed by inoculating 5 mL in each of the FA and FN BACT/ALERT° broths (BIOMERIEUX°) at 37°C + 1 mL in Sabouraud broth at 22°C (incubation for 10 days). The results were analyzed by distinguishing phase A (EUROBIO° alone used in the bank), phase B (the two media used), and phase C (ALCHIMIA° alone)Results The sterility test was validated with the strains of the European pharmacopoeia, except for P. aeruginosa, not detected in these conditions with TissueC°. Microbiological contamination rate was lower with ALCHIMIA° (2.5%) than with EUROBIO° (5.9%) due to the absence of fungus detected with ALCHIMIA°. CG preserved in ALCHIMIA° medium displayed a greater thickness and lower transparency than EUROBIO° corneas. For some CG, the cells are not turgid. During the phase B, ECD determination was more difficult with ALCHIMIA°: the addition of two one-minute rinses in NaCl0,9% improved this critical step. This change was also adopted for EUROBIO° CG. The% of CG with cellularity >2000/mm2 was 46% with EUROBIO° (phase A), much lower than 62.1% with ALCHIMIA° in phase C. However, during the phase B, this percentage was similar with EUROBIO° (59.6%) and ALCHIMIA° (61.9%), indicating that this increase was related to the modified ECD determination method and not to the medium.Conclusions The change in the ECD determination method resulted in a decrease of 16% of rejected corneas. May the lower osmolarity of TissueC° explain the corneal morphological characteristics observed? ALCHIMIA° media usage eliminated 2.5% of fungal contamination. The laboratory plans to reduce the inoculum of the sterility test to allow the detection of P. aeruginosa.