Characterization of Endothelial Cell Loss in Pre-Descemet Endothelial Keratoplasty Graft Preparation

Purpose:To characterize the pattern and factors affecting endothelial cell loss (ECL) in pre-Descemet Endothelial Keratoplasty (PDEK) graft preparation.Methods:A prospective study was performed to characterize the pattern of ECL and the impact of inflation pressure in PDEK. Donor corneas were randomized to inflation with air versus Optisol GS storage media. PDEK preparation was performed under continuous pressure monitoring. Trypan blue was used to grade the tissue as acceptable (<25% ECL) or unacceptable (≥25% ECL). Rate of unacceptable ECL was correlated with injection media type and inflation pressure. A retrospective study was then performed of all attempted PDEK preparations at Lions Gift of Sight to evaluate impact of donor tissue factors on ECL. Donor age and tissue preservation time were evaluated and correlated with ECL with PDEK bubbling.Results:Twenty-five corneas were tested prospectively. A reticular pattern of ECL that varied in severity occurred with bubbling. There was no difference in peak inflation pressure or mean expansion pressure between air (706.0, 510.7 mm Hg) and Optisol GS (852.9, 653.0 mm Hg). Increasing peak inflation pressure and mean expansion pressure were associated with an increased risk for unacceptable ECL. On retrospective evaluation of 131 attempted PDEKs, only 44.0% of cases with successful bubbles had acceptable endothelium after processing. Increasing donor age and decreasing preservation time were associated with increased rates of acceptable endothelium.Conclusions:PDEK processing can result in a reticular pattern of ECL. Higher inflation pressures are associated with greater ECL. Older donor tissues with shorter preservation times might be preferable for PDEK.