| Popis: |
Purpose To assess the viable endothelial cell density (vECD) of posterior lamellar grafts, stored in organ culture, precut by eye bank technicians, and sent to a distant center. Methods Paired corneas with an ECD >2200 cells/mm2 at the standard assessment with the SambaCornea analyser (TribVn, France), were stored in CorneaMax (Eurobio, France) and deswelled in CorneaJet (5% Dextran T500) for 6 to 24 hours prior to pre-cutting. They were randomly assigned as full-thickness grafts or as precut posterior transplants for DSAEK using a microkeratome with a 350μm head (Moria, France). Corneas were sent to a distant center where the vECD was assessed by using the triple Hoechst/Ethidium/Calcein (HEC) staining and fluorescent image analysis of the entire posterior surface: calculation of the area covered by living cells (H+/C+/E-) coupled with counting of nuclei in large areas allowed to determine the vECD, i.e. the useful cell pool (Pipparelli. IOVS 2011.52:6018). DSAEK and controls data were compared with non-parametric tests. Results In both groups, the vECD was lower than the standard ECD determined by the eye bank (for 20±7% for full thickness grafts, 34±16% for DSAEK), because living cells never completely covered the entire posterior surface. vECD were respectively of 2006+/-349 vs 1661+/-464 (P=0.075). Conclusion The HEC triple staining combined with image analysis provides a unique accurate assessment of the endothelial quality by giving the vECD. This laboratory technique allows a reliable assessment of the endothelial quality of tissues supplied to surgeons, precut or not. It can also be used to assess any methods liable to modify EC. |
Plný text