Pre‐cut posterior corneal lamellae with a stromal rim used for Descemet’s membrane endothelial keratoplasty with a stromal rim (DMEK‐S)

Abstract

Abstract Purpose To standardize a technique for the manual preparation of posterior corneal lamellae for DMEK‐S under the conditions of an ocular tissue bank. To assess the qualitative and quantitative parameters of the lamellar endothelium with the aim of establishing the parameters of corneas intended for preparation. Methods Corneoscleral buttons 17mm in diameter not suitable for grafting were used. Group 1 contained 12 corneas with a live endothelial cell density ≥ 2500 cells/mm2. Group 2 contained 10 corneas with a density lower than 2500 cells/mm2. The lamellae, consisting of a central 6mm zone of endothelium‐Descemet’s membrane surrounded by a supporting peripheral stromal rim, were prepared manually using the big bubble technique. The percentage of dead cells and the live endothelial cell density were assessed before and immediately after preparation as well as after 48 hours of organ culture storage using light microscopy following 0.15% trypan blue and 0.9% sucrose treatment. Results Immediately after the preparation, on average 4.9 % and 5.2 % of dead cells were found in group 1 and group 2, respectively. The percentage of dead cells decreased significantly during subsequent storage in organ culture in both groups (to 1.5 % and 1.7 % for group 1 and 2). There was no significant decrease in live endothelial cell density in group 1 during 48 hours of culturing; however, there was a significant decrease in group 2. Conclusion The decrease in endothelial cell density during organ culturing depends on the original values. We suggest that the minimal acceptable live endothelial cell density of corneas intended for preparation should be 2500 cells/mm2 to ensure the best clinical outcomes.