Purpose: To evaluate the suitability of corneas from septic donors for transplantation by analyzing the discard rate in the eye bank and the clinical outcome of Descemet membrane endothelial... Show morePurpose: To evaluate the suitability of corneas from septic donors for transplantation by analyzing the discard rate in the eye bank and the clinical outcome of Descemet membrane endothelial keratoplasty (DMEK) using organ-cultured corneal grafts from septic versus nonseptic donors. Methods: This retrospective study included 1554 corneas of which 456 corneas (29%) were from septic and 1072 corneas (69%) from nonseptic donors [for 26 corneas (2%) sepsis status was unknown]. The clinical outcome at 6 months after DMEK was evaluated for 82 grafts (26 from septic and 56 from nonseptic donors). Outcome measures were endothelial cell density, central corneal thickness, and postoperative complications. Results: Primary discard rates were higher for corneas from septic than from nonseptic donors (32.9% vs. 24.5%, P = 0.001). The main discard reason was poor endothelial cell quality for both septic (13.8%) and nonseptic (11.8%) donor corneas. Eye bank contamination rates for septic and nonseptic donor corneas were 1.1% and 1.7%, respectively (P = 0.102). After DMEK, donor endothelial cell density at 6m postoperatively was comparable between grafts from septic and nonseptic donors (1410 +/- 422 cells/mm(2) vs. 1590 +/- 519 cells/mm(2), P = 0.140). No differences in 6m central corneal thickness and in the rebubbling rate were observed between the 2 groups (P = 0.780 and P = 0.396, respectively). None of the cases had graft rejection nor endophthalmitis in both groups. Conclusions: Provided strict adherence to donor screening and evaluation protocols, the use of organ-cultured corneas from septic donors for DMEK does not seem to increase the risk for recipients and allows for expansion of the donor pool for corneal tissue. Show less
Corneal diseases are among the leading causes of reversible blindness worldwide. When conservative treatment options fail, many eyes can be treated with corneal transplantation. Historically, full... Show moreCorneal diseases are among the leading causes of reversible blindness worldwide. When conservative treatment options fail, many eyes can be treated with corneal transplantation. Historically, full thickness corneal transplantation, in which all corneal layers are replaced, has been the mainstay of care in the treatment of corneal endothelial disorders. In the past two decades, however, there has been a trend towards the selective, less invasive replacement of only the diseased, rather than all corneal layers. These partial thickness corneal transplantations are known as lamellar keratoplasties. Lamellar keratoplasty has significantly improved the clinical outcomes, such as visual acuity, after transplantation. Since its introduction in 1998, lamellar keratoplasty has evolved from Deep lamellar endothelial keratoplasty to Descemet membrane endothelial keratoplasty (DMEK). Globally, however, there is only one donor cornea available for 70 people in need. This shortage inspired further refinement of conventional DMEK and led to the development of adapted DMEK-techniques, which may increase the availability of endothelial donor grafts. This thesis focuses on donor tissue preparation for DMEK and evaluates the feasibility and clinical outcomes of DMEK, DMET, Hemi-DMEK and Quarter-DMEK in the management of corneal endothelial disorders. Show less
Aim Studying cell migration of corneal endothelial cellsin vitrois challenging because the capacity for cell migration needs to be maintained while at the same time the tissue must remain fixed on... Show moreAim Studying cell migration of corneal endothelial cellsin vitrois challenging because the capacity for cell migration needs to be maintained while at the same time the tissue must remain fixed on a rigid substrate. In this study, we report a thermoresponsive culture technique designed to maintain cellular viability, and to reduce tissue handling in order to analyzein vitroendothelial cell migration from corneal grafts. Materials and Methods As a test tissue, fifteen Quarter-Descemet membrane endothelial keratoplasty (Q-DMEK) grafts were used that were embedded in a three-dimensional culture system using a temperature-reversible hydrogel and cultured over 2-3 weeks in a humidified atmosphere at 37 degrees C and 5% CO2. Results All grafts could be successfully cultured inside the thermoresponsive polymer solution for periods of up to 21 days. Using this system, cell migration could be assessed by light microscopy at fixed time intervals. At the end of the culture period, the gel could be removed from all grafts and immunohistochemistry analysis showed that endothelial cells were able to maintain confluence, viability, and junctional integrity. Some problems were encountered when using the thermoresponsive cell culture system. These were mostly structural inconsistencies during the sol-to-gel transition phase that resulted in the formation of tiny bubbles in the matrix. Additionally, areas with different viscosity resulted in optical distortions showing up as folds throughout the matrix which can persist even after several cycles of culture medium exchange. These effects had impact on the imaging quality but did not affect the viability of the explant tissue. Conclusion This study proves that temperature-reversible hydrogel is a very useful matrix for studyingin vitrocorneal endothelial cell migration from explant grafts and allows for subsequent biological investigation after gel removal. Show less
Purpose:To report the 5-year graft survival and clinical outcomes after Descemet membrane endothelial keratoplasty (DMEK).Methods:A retrospective, interventional case series was performed at a... Show morePurpose:To report the 5-year graft survival and clinical outcomes after Descemet membrane endothelial keratoplasty (DMEK).Methods:A retrospective, interventional case series was performed at a tertiary referral center. Five hundred eyes of 393 patients that underwent DMEK for Fuchs endothelial corneal dystrophy, bullous keratopathy, failed previous corneal transplants other than DMEK, or other indications were evaluated for graft survival, best-corrected visual acuity (BCVA), endothelial cell density, postoperative complications, and retransplantation rate.Results:Kaplan-Meier analysis demonstrated an estimated survival probability of 0.90 [95% confidence interval, 0.87-0.94] for the entire cohort at 5 years after DMEK. At this time point, 82% of the eyes achieved a BCVA of >= 20/25 (0.8), 54% achieved >= 20/20 (1.0), and 16% achieved >= 20/17 (1.2). BCVA continued to improve from 6 to 36 months after DMEK surgery (P <= 0.005) and then remained stable up to 60 months postoperatively (P > 0.08). Preoperative donor endothelial cell density averaged 2530 (210) cells/mm(2) and decreased by 37% at 6 months, 40% at 1 year, and 55% at 5 years after DMEK surgery (P < 0.001 between all follow-up time points). During the study period, allograft rejection episodes developed in 2.8% of the eyes, primary graft failure occurred in 0.2%, and secondary graft failure in 2.8% of the eyes. Re-keratoplasty was required in 8.8% of the eyes.Conclusions:Five-year graft survival after DMEK is high, and visual acuity outcomes remain excellent and are accompanied by a low longer-term complication rate. Show less
Purpose:To report clinical outcomes of the first Quarter-Descemet membrane endothelial keratoplasty (Quarter-DMEK) case series performed for central Fuchs endothelial corneal dystrophy.Methods:This... Show morePurpose:To report clinical outcomes of the first Quarter-Descemet membrane endothelial keratoplasty (Quarter-DMEK) case series performed for central Fuchs endothelial corneal dystrophy.Methods:This is a prospective, interventional case series analyzing the clinical outcomes of 19 eyes of 19 patients with central Fuchs endothelial corneal dystrophy, that is, with guttae predominantly in the 6- to 7-mm optical zone, who underwent unilateral Quarter-DMEK at a tertiary referral center. Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD), and postoperative complications. Included eyes had up to 2 years of postoperative follow-up.Results:At 6 months postoperatively, all eyes reached a BCVA of >= 20/40 (>= 0.5): 18 of 19 eyes (95%) with >= 20/25 (>= 0.8) and 9 of 19 eyes (42%) with >= 20/20 (>= 1.0). Thereafter, BCVA remained stable up to 2 years postoperatively. The mean donor ECD decreased from 2842 139 cells/mm(2) (n = 19) before implantation to 913 +/- 434 cells/mm(2) (-68%) at 6 months (n = 19), 869 +/- 313 cells/mm(2) (-70%) at 12 months (n = 18), and 758 +/- 225 cells/mm(2) (-74%) at 24 months (n = 13) after Quarter-DMEK. Visually significant graft detachment requiring rebubbling occurred in 8 of 19 eyes (42%).Conclusions:Quarter-DMEK surgery yields visual outcomes similar to those of conventional DMEK and may potentially quadruple the availability of endothelial grafts. Further modifications of the graft preparation and the surgical technique may improve clinical outcomes in terms of lower ECD decrease and fewer graft detachments. Show less
