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Purpose: To investigate the adhesive and stiffness properties of prestripped Descemet membrane endothelial keratoplasty (DMEK) lenticules in different preservation conditions (with and without dextran)., Methods: The study included 3 conditions: (C1) tissues collected from tissue culture media (TCM), stripped and preserved in TCM; (C2) tissues collected from transport media (TM) (TCM supplemented with 6% dextran T-500), stripped and preserved in TM; and (C3) tissues collected from TCM, stripped and preserved in TM. Using a hinge, 9.5-mm stripped DMEK lenticules were restored back on the stroma and preserved for 4 days at room temperature (RT) in different conditions as above. Nine tissues, 3 from each condition, were used to check the adhesive (fibronectin, laminin, and vitronectin) and elastic properties (fibrillin, elastin, and collagen VI) using different antibodies. Six tissues, 2 from each condition, were used to check the stiffness properties after preservation using atomic force microscopy (AFM) nanoindentation method., Results: On the Descemet membrane, fibronectin was strongly expressed in C2 and C3, whereas laminin was intense in C2 postpreservation. Vitronectin was expressed in all the conditions. Elastic proteins were not expressed in either of the conditions apart from collagen VI, which was expressed on the posterior stroma. Atomic force microscopy showed higher stiffness in C3 and an insignificant but lower rigidity in C2 as compared to C1., Conclusions: The tissues from C2 showed expression of adherent proteins and lower stiffness. Dextran may be suitable in preservation of DMEK grafts before and after preparation. Less stiff tissues may help reduce manipulations required in the recipient eye during DMEK surgery.

Purpose: Trypan blue (TB) is used for visualization of the endothelium-Descemet membrane graft during Descemet membrane endothelial keratoplasty (DMEK). However, TB is assumed to have a dose-dependent toxic effect on the corneal endothelium. We retrospectively compared a lutein/zeaxanthin and Brilliant Blue (LZ/BB)-based dye for preparation and transplantation of the graft in DMEK to TB., Methods: In 20 patients, a dye composed of 1% LZ /0.025% BB was used, and in 22 patients, 0.06% TB was used for graft visualization in DMEK. We evaluated the rebubbling rate, best spectacle-corrected visual acuity (BSCVA), central corneal thickness (CCT), and endothelial cell density (ECD) before and 3 and 6 months after transplantation., Results: Staining of endothelium-Descemet membrane with LZ/BB was faint but sufficient. There was no significant difference between both groups, except in CCT after 3 months, which was lower in the LZ/BB group (P = 0.02). In the LZ/BB group, BSCVA improved from 0.48 ± 0.39 before DMEK to 0.19 ± 0.09 after 6 months (P < 0.05) (20% rebubbling rate). Donor ECD decreased from 2735 ± 259 cells/m preoperatively to 1876 ± 316 cells/mm (P < 0.0001) at 6 months (31.4%). CCT decreased from 642 ± 130 μm preoperatively to 519.8 ± 38 μm (P < 0.0001) at 6 months. In the TB group, BSCVA improved from 0.43 ± 0.27 to 0.17 ± 0.14 (P = 0.0003) at 6 months (30% rebubbling rate). ECD decreased from 2825 ± 263 to 1777 ± 302 cells/mm (P < 0.0001) after 6 months (36.3%), CCT from 638 ± 48 μm preoperatively to 531 ± 48 μm (P < 0.0001) at 6 months., Conclusions: LZ/BB-based dyes are suitable for DMEK with outcomes comparable to TB. However, available formulas result in faint staining, discouraging their routine use in donors with assumed difficult preparation.

A 65-year-old woman with iridocorneal endothelial syndrome and a history of Ahmed glaucoma drainage (AGD) tube implantation underwent Descemet stripping automated endothelial keratoplasty (DSAEK) in her right eye. During the procedure, filling the anterior chamber with air was quite difficult due to escape of air via the AGD tube and a complete air fill of the anterior chamber could only be managed after multiple attempts. On operation night, there was no air left in the anterior chamber. On postoperative day 1, graft detachment was determined by slit-lamp biomicroscopy. For rebubbling, sulfur hexafluoride (SF(6)) 20 % was injected into the anterior chamber. Two days later, there was still some SF(6) in the anterior chamber and the graft was completely attached. At postoperative week 2, visual acuity was 2/10. SF(6) use may be considered for DSAEK in cases of previous AGD tube implantation history due to its potential for longer duration in order to obtain a better tamponade with the bubble due to its expanding nature.