Clinical outcome analysis of two approaches to trypan blue dyeing for DMEK

Abstract Background: To evaluate the clinical implications of the different trypan blue dyeing techniques used during liquid bubble (LBT) and manual peel (MPT) DMEK lenticule preparation techniques. Methods: This study retrospectively compared the degree to which endothelial cells are preserved using selective Descemet Membrane (DM) staining (LBT) versus bath-staining (MPT) when performed by a single surgeon, sourced from a single eye bank. Results: Endothelial cell density measured after the 3-month follow-up was 1805 and 1916 cells/mm2 respectively, differing significantly (p= 0.012). A double-scroll graft formation was found and maintained until implantation in 94% of preparations with bath staining and 50% of preparations using selective DM staining. Preoperative visual acuity was comparable between preparation techniques at 0.4 logMAR as well as postoperatively, at an average of 0.1 logMAR. Conclusions: Reducing chemical stress on the endothelium by avoiding any contact with trypan blue allows for a significantly higher degree of cell preservation. However, achieving the often-desired double-scroll graft formation was possible less frequently. It remains unclear which factors define the differences graft scrolling behavior observed between LBT and MPT.