Clinical Comparison of Two Methods of Graft Preparation in Descemet Membrane Endothelial Keratoplasty.

PURPOSE: Descemet membrane endothelial keratoplasty (DMEK) has been improved over the last decade. The aim of this study was to compare the clinical outcome of the recently introduced liquid bubble method compared to the standard manual preparation. METHODS: This retrospective study evaluated the outcome of 200 patients after DMEK surgery using two different graft preparation techniques. Ninety-six DMEK were prepared by manual dissection and 104 by the novel liquid bubble technique. The mean follow-up time was 13.7 months (SD ± 8, range 6-36 months). RESULTS: Best corrected mean visual acuity (BCVA) increased for all patients statistically significant from baseline 0.85 logMAR (SD ± 0.5) to 0.26 logMAR (SD ± 0.27) at the final follow-up (Wilcoxon, p = 0.001). Subgroup analyses of BCVA at the final follow-up between manual dissection and liquid bubble preparation showed no statistically significant difference (Mann-Whitney U Test, p = 0.64). The mean central corneal thickness was not statistically different (manual dissection: 539 µm, SD ± 68 µm and liquid bubble technique: 534 µm, SD ± 52 µm,) between the two groups (Mann-Whitney U Test, p = 0.64). At the final follow-up, mean endothelial cell count of donor grafts was statistically not significant different at the final follow-up with 1761 cells/mm2 (-30.7%, SD ± 352) for manual dissection compared to liquid bubble technique with 1749 cells/mm2 (-29.9%, SD ± 501) (Mann-Whitney U-Test, p = 0.73). The re-DMEK rate was comparable for manual dissection with 8 cases (8.3%) and 7 cases (6.7%) for liquid bubble dissection (p = 0.69, Chi-Square Test). CONCLUSION: Regarding the clinical outcome, we did not find a statistical significant difference between manual dissection and liquid bubble graft preparation. Both preparation techniques lead to an equivalent clinical outcome after DMEK surgery.

Novel liquid bubble dissection technique for DMEK lenticule preparation.

PURPOSE: Descemet endothelial keratoplasty (DMEK) has replaced penetrating keratoplasty in many cases of endothelial cell disorders. While DMEK has been greatly improved by the introduction of no-touch injection cartridges, the tear-free preparation of the delicate Descemet's membrane (DM) remains a critical step. We present a novel liquid bubble dissection technique for DM preparation that could offer several advantages. METHODS: After identification of the iris base, a sharp dissection until Schwalbe's line was performed. Then, a narrow tunnel was created with a blunt spatula using a tangential dissection technique. After the tunnel was created, the liquid bubble dissection was performed. The complete detachment process took only a few seconds after a successful preparation of the tunnel in the correct plane between the DM and corneal stroma. RESULTS: Between February and September 2015, we consecutively performed 86 DMEK lenticule preparations using the liquid bubble technique. The preparation time until complete detachment was about 3 min (mean 194 ± 20 s). Ninety-two percent of preparations were completely uncomplicated; the total success rate was 99 %. One graft could not be used for transplantation because of a central tear. The graft failure rate was 1.16 %, similar to other authors. CONCLUSIONS: The presented novel liquid bubble technique is easy, can be learned and performed rapidly, is highly reproducible in a standardized fashion with minor tissue manipulation (no touch) and, with a low rate of graft preparation failure, necessitates no special equipment and allows for a simultaneous and selective staining of the stromal side of DM, thus avoiding direct contact.

Influence of Testosterone on Inflammatory Response in Testicular Cells and Expression of Transcription Factor Foxp3 in T Cells.

PROBLEM: Previous studies demonstrated a strong association between low androgen levels and reduced capacity to mount an inflammatory response. However, the mechanisms underlying these observations are largely not understood. METHODS OF STUDY: Generation of CD4+CD25+Foxp3+ regulatory T cells in Leydig cell-conditioned media was determined by flow cytometry and ELISA. Influence of testosterone on cytokine response was measured in LPS-stimulated testicular macrophages, Sertoli and peritubular cells. RESULTS: Leydig cell-conditioned media dose-dependently stimulated expression of transcription factor Foxp3 and secretion of IL-10 in splenic CD4+ T cells, an effect abolished by addition of the anti-androgen flutamide. In isolated Sertoli and peritubular cells, testosterone pre-treatment suppressed the LPS-induced inflammatory response on TNF-α mRNA expression, while no effect was evident in testicular macrophages (TM). CONCLUSIONS: Androgens can influence the immune system under normal conditions by the generation and functional differentiation of regulatory T cells and in testicular inflammation by direct effect on Sertoli and peritubular cells.