Jacqueline van der Wees

Donor tissue preparation for Descemet membrane endothelial keratoplasty

PURPOSE: To evaluate a technique for preparing a donor Descemet membrane carrying autologous endothelium for transplantation in Descemet membrane endothelial keratoplasty (DMEK). SETTING: Netherlands Institute for Innovative Ocular Surgery, Rotterdam, The Netherlands. METHODS: A 9.5 mm diameter DM carrying autologous endothelium was stripped from 10 corneoscleral rims that had been organ cultured for 1 week. The endothelial cell density (ECD) was evaluated with light microscopy before and immediately after DM was stripped and during 4 additional weeks of organ culture. RESULTS: The mean ECD was 2701 cells/mm2 ± 302 (SD) before and 2719 ± 322 cells/mm2 immediately after DM was stripped and declined from 2604 ± 352 cells/mm2 after 1 week to 2190 ± 768 cells/mm2 after an additional 4 weeks of organ culture (n = 10). Typical “endothelial streaks,” ie, linear cellular disruptions observed immediately after DM was stripped, showed complete regeneration after the second culture period. CONCLUSIONS: Descemet grafts for transplantation in DMEK procedures can be surgically prepared from organ‐cultured corneal rims and stored for an additional 3 weeks with acceptable endothelial cell loss. Because the donor tissue can be dissected directly from organ‐cultured corneoscleral rims, donor preparation for DMEK can be readily accessible to most corneal surgeons.

Visual Rehabilitation Rate After Isolated Descemet Membrane Transplantation: Descemet Membrane Endothelial Keratoplasty

OBJECTIVE To evaluate visual rehabilitation after Descemet membrane endothelial keratoplasty (DMEK) in the management of corneal endothelial disorders. METHODS In this prospective, nonrandomized, clinical study, DMEK was performed in a first group of 35 consecutive patients with either Fuchs endothelial dystrophy or bullous keratopathy. The Descemet membrane was stripped from the recipient posterior stroma with the anterior chamber completely filled with air. Using a 3.0-mm clear corneal incision, an organ-cultured donor Descemet roll 9 to 10 mm in diameter was inserted into the recipient anterior chamber, positioned on the posterior stroma, and secured by completely filling the anterior chamber with air for 45 to 60 minutes. RESULTS Ten eyes had preexisting ocular disease or an early graft detachment. In the remaining 25 DMEK-treated eyes, best-corrected visual acuity was 20/40 (Snellen notation, 0.5) or more in 18 eyes (72%) within 1 month. At 3 months, best-corrected visual acuity was 20/40 (0.5) or more in 23 of 25 eyes (92%) and 20/25 (0.8) or more in 15 of 25 eyes (60%). CONCLUSIONS In most cases, DMEK results in functional visual rehabilitation within 1 to 3 months. Overall, visual recovery after DMEK may be faster and more complete than with other techniques for (lamellar) keratoplasty for treatment of corneal endothelial disorders. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00521898.

Endothelial Cell Density After Descemet Membrane Endothelial Keratoplasty: 1- to 3-Year Follow-up

PURPOSE To evaluate donor endothelial cell density (ECD) after Descemet membrane endothelial keratoplasty (DMEK). DESIGN Nonrandomized, prospective clinical study. METHODS From a larger group of patients who underwent DMEK for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy, complete ECD measurements were available of 26 patients with 6 and 12 months of follow-up, of whom 7 also had 24 months of follow-up. RESULTS For the group with 24 months of follow-up, ECD averaged 2700 (+/- 260) cells/mm(2) before surgery, 2200 (+/- 460) cells/mm(2) at 6 months after surgery, 2050 (+/- 330) cells/mm(2) at 12 months after surgery, and 1780 (+/- 390) cells/mm(2) at 24 months after surgery. For the group with 12 months of follow-up, ECD averaged 2620 (+/- 210) cells/mm(2) before surgery, 1850 (+/- 540) cells/mm(2) at 6 months after surgery, and 1680 (+/- 550) cells/mm(2) at 12 months after surgery. In both groups, the ECD decreased significantly between the preoperative and 6-month measurement (P < .05). CONCLUSIONS Similar to earlier endothelial keratoplasty techniques, DMEK may be associated with a decrease in donor ECD of approximately 25% in the early postoperative phase.

Standardized ‘no-touch’ donor tissue preparation for DALK and DMEK: harvesting undamaged anterior and posterior transplants from the same donor cornea

Purpose:  To describe a standardized ‘no‐touch’ harvesting technique of anterior and Descemet membrane (DM) grafts for use in deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK), which provides undamaged anterior and posterior corneal grafts.

Back-up procedure for graft failure in Descemet membrane endothelial keratoplasty (DMEK)

Aim To evaluate the efficacy of a secondary Descemet stripping endothelial keratoplasty (DSEK) as a back-up procedure for managing graft failure after primary Descemet membrane endothelial keratoplasty (DMEK). Design Non-randomised prospective clinical study. Methods A first group of 50 cases with Fuchs endothelial dystrophy underwent DMEK. Two to five weeks after the DMEK, 10 cases showed no corneal clearance, so a secondary DSEK was performed. To evaluate the eyes of these 10 cases, best corrected visual acuity (BCVA) and endothelial cell density at 6 and 12 months were used as outcome parameters. Results At 6 months after secondary DSEK, 87% of the cases had a BCVA of ≥20/40 (≥0.5) and one eye reached 20/25 (≥0.8). Donor DSEK grafts endothelial cell densities averaged 2617±152 cells/mm2 before surgery, 1510±799 cells/mm2 at 6 months and 1602±892 cells/mm2 at 12 months after surgery. Conclusion In the event of a DMEK graft failure, a secondary DSEK may be an effective back-up procedure, as it may give a clinical outcome similar to that after a primary DSEK. Particularly during the surgeons learning curve, patient information may be provided not only on visual outcomes after DMEK, but also after DSEK. Trial registration number NCT00521898.

Simple technique for graft insertion in Descemet-stripping (automated) endothelial keratoplasty using a 30-gauge needle

&NA; We describe a needle insertion technique for graft insertion in Descemet‐stripping (automated) endothelial keratoplasty (DSEK/DSAEK). A folded donor posterior corneal disk is inserted through a 5.0 mm scleral tunnel incision over a plastic glide using a 30‐gauge needle. The technique enables safe and easy graft insertion without vertical or horizontal compression of the donor tissue, causing minimal trauma to the donor endothelium and/or host structures.

Isolated Bowman layer transplantation to manage persistent subepithelial haze after excimer laser surface ablation

In a 21-year-old patient with persistent dense subepithelial haze after photorefractive keratectomy, unresponsive to retreatment, a stromal flap, 9.0 mm in diameter and approximately 60 microm in thickness, was excised and an unsutured 9.0 mm donor Bowman layer was transplanted onto the stromal bed. The corrected distance visual acuity improved from 20/40 (0.5) before surgery to 20/18 (1.2) with a scleral-supported contact lens 2 months after transplantation. With optical coherence tomography, the transplanted Bowman layer was seen as a fine white line bordering the anterior host stroma. No recurrence of stromal haze was seen throughout the 6-month follow-up. Isolated Bowman layer transplantation may be a new technique for the management of anterior stromal opacities or complicated epithelial wound healing such as persistent corneal haze after excimer laser surface ablation.

Association Between Graft Storage Time and Donor Age With Endothelial Cell Density and Graft Adherence After Descemet Membrane Endothelial Keratoplasty

IMPORTANCE After retrospectively evaluating the clinical outcome of 500 consecutive cases after Descemet membrane endothelial keratoplasty (DMEK), we extended the analysis in this study by assessing the effect of donor-related parameters on endothelial cell density (ECD) decline and detachment rate in this group. OBSERVATIONS This retrospective case series included 500 cases who had undergone DMEK from October 2007 to September 2012 at the Netherlands Institute for Innovative Ocular Surgery (NIIOS), Rotterdam, the Netherlands. Logistic regression analysis (n = 332 eyes) showed that donor age might be associated with a 3% increase in the risk for a detachment (odds ratio, 0.97; 95% CI, 0.94-1.00; P = .049) (ie, higher donor age seems to be associated with lower chances of a detachment). In addition, linear regression analysis indicated that graft storage time in medium was associated with ECD decrease (ie, the longer the storage time, the larger the decrease at 6 months after DMEK) (P = .01). CONCLUSIONS AND RELEVANCE We showed an association between graft storage time and ECD decline after DMEK and possibly between donor age and graft detachment. Therefore, donor storage times should be kept as short as possible to improve short-term ECDs. More research is needed to draw definite conclusions on the possible effect of donor age on the chance of a detachment after DMEK.

Postmortem ultrastructural analysis of a cornea transplanted with Descemet membrane endothelial keratoplasty.

Purpose: The aim of this study was to describe the ultrastructure of the host–donor interface in the eye of a recently deceased patient, who had undergone Descemet membrane endothelial keratoplasty. Methods: The eye was enucleated postmortem, and after standard decontamination, the corneoscleral button was excised, cut into 4 quadrants, and processed for light and transmission electron microscopy evaluation. Results: Transmission electron microscopy revealed close attachment of the donors Descemet membrane to the hosts stroma and projection of stromal collagen fibers into the interfacial matrix, resembling a normal “virgin” corneal architecture. Conclusions: Ultrastructurally, an attached Descemet membrane endothelial keratoplasty graft closely resembles that of an unoperated, healthy eye with no appreciable adventitious or missing structures.

Radial graft contraction may relate to subnormal visual acuity in Descemet stripping (automated) endothelial keratoplasty

Since 1998, we have introduced various concepts for endothelial keratoplasty, popularised as ‘deep lamellar endothelial keratoplasty’ (DLEK), ‘Descemet stripping (automated) endothelial keratoplasty’ (DSEK/DSAEK) and ‘Descemet membrane endothelial keratoplasty’ (DMEK).1 Large clinical studies on DSEK/DSAEK reported a best-corrected visual acuity (BCVA) averaging 20/40 (0.5) at 6 months after surgery, with only few cases reaching ≥20/25 (≥0.8).2 3 In a first series of DMEK surgeries for Fuchs endothelial dystrophy, a majority of cases reached ≥20/25 (≥0.8).4 Apparently, a cornea may obtain a better optical performance after transplantation of an isolated donor Descemet membrane and its endothelium in DMEK, than with a thicker graft also containing donor posterior stroma as used in DSEK/DSAEK.1 If so, compromised optical quality of the transplanted cornea may relate to the presence of donor stroma in DSEK grafts. In this letter, we describe a potential mechanism of how donor posterior stroma may limit final BCVA in endothelial keratoplasty, by progressive graft contraction. A …