Donor Descemet Membrane Research Articles

Double-Cannula Maneuver for the Double-Roll Configuration of Donor Descemet Membrane Outside Recipient Anterior Chamber During Descemet Membrane Endothelial Keratoplasty.

The purpose of this study was to present a new surgical technique to convert a single roll of Descemet membrane (DM) into a double roll using 2 cannulas in a balanced salt solution-filled Petri dish during DM endothelial keratoplasty. A single DM roll stained with trypan blue was placed in a balanced salt solution-filled Petri dish. Two cannulas (28G) were introduced from opposite ends of the single roll, inserted into the roll, and slowly spread apart to change the single roll into a double roll. The DM was aspirated into the modified Jones tube and loaded, maintaining a double-roll configuration with endothelium-down orientation in a bevel-up position. The modified Jones tube with the bevel down was inserted into the recipient anterior chamber through the main wound. The modified Jones tube was rotated to the bevel-up orientation. After checking the graft orientation, the DM was inserted into the recipient anterior chamber. The double-roll DM was easily unfolded by tapping the center of the cornea using a cannula. A 28G cannula was inserted under the DM, and the anterior chamber was filled with air. Three months after surgery, the patient's corrected visual acuity in the right eye was 6/7.5 and the endothelial cell count was 1095/mm2. The corneal thickness was 533 μm, and the cornea was clear. The double-cannula maneuver mechanically changes the single roll of the donor DM to a double roll outside the recipient anterior chamber, making DM unfolding easier and minimizing the risk of upside-down apposition of the donor DM.

Risk Factors for Descemet Membrane Endothelial Keratoplasty Rejection: Current Perspectives- Systematic Review.

Descemet membrane endothelial keratoplasty (DMEK) is a corneal endothelial transplantation procedure with selective removal of a patient's defective Descemet membrane and endothelium. It is replaced with a healthy donor Descemet membrane and endothelium without a stromal component. Corneal graft rejection can be at the level of epithelium, stroma as well endothelium. DMEK graft rejection is relatively less common than rejection with DSAEK or penetrating keratoplasty, and a good outcome may be achieved with prompt management. The clinical picture of DMEK rejection is usually similar to endothelial rejection in Descemet Stripping Endothelial Keratoplasty (DSEK/DSAEK), which generally manifests as pain, redness, reduction in visual acuity, stromal edema, endothelial rejection line, keratic precipitates at the back of the cornea and corneal neovascularization. However, more subtle forms of rejection or immune reactions are more common in DMEK compared to DSAEK eyes. Early clinical diagnosis, prompt intervention, and meticulous management safeguard visual acuity and graft survival in these cases. Intensive topical steroids form the mainstay in the management of DMEK rejection. Sometimes, oral or intravenous steroids or other systemic immunomodulators may be required. DMEK graft failure can be primary or secondary, and failure usually requires a second procedure in the form of repeat DMEK or DSEK or penetrating keratoplasty (PKP). A detailed literature search was performed using search engines such as Google Scholar, PubMed, and Google books, and a comprehensive review on DMEK rejection was found to be lacking. This review is a comprehensive update on the risk factors, pathophysiology, primary and secondary graft failure, recent advances in diagnosis, prevention of rejection, and updates in the management of DMEK rejection. The review also discusses the differential diagnosis of DMEK failure and rejection, prognosis, and future perspectives considering DMEK failure and rejection.

Post-Descemet's membrane endothelial keratoplasty Pseudomonas graft infection

To report evaluation and management of graft-host interface keratitis post-Descemet's membrane endothelial keratoplasty (DMEK). A 70-year-old lady with pseudophakic bullous keratopathy who underwent DMEK and developed interface interstitial keratitis on the first postoperative day. Cultures of corneal button revealed gram-negative bacilli (Pseudomonas aeruginosa). Prompt surgical intervention in the form of removal of donor Descemet's membrane and targeted antibacterial therapy helped in the complete resolution of infection. Descemet's stripping endothelial keratoplasty (DSEK) was performed postresolution of infection which yielded a good visual outcome for the patient. Donor rim culture helps immensely in identifying organisms in cases presenting in the early postoperative period.

Graft Size and Double Scroll Formation Rate in Descemet Membrane Endothelial Keratoplasty

Purpose This study aimed to evaluate the usefulness of intentional double scroll formation of donor Descemet membrane (DM) inside a glass tube inserter (the Fogla technique) in DM endothelial keratoplasty (DMEK) for controlled insertion and unfolding of grafts. Methods Eleven consecutive patients who underwent DMEK were included in this study. We sought to specify graft characteristics in which double scroll configuration was successfully formed using the Fogla technique. We compared donor age, graft size, surgical time, unfolding time, and visual outcomes between patients with and without double scroll configuration. The ability to form double scroll formation of DM grafts of various diameters and unfolding time of DM grafts was evaluated using total seven eye-bank eyes in ex vivo experiments. Results A double scroll configuration inside a glass tube was successfully obtained in six DMEK grafts (54.5%). When comparing clinical features between those with and without double scroll configuration, only graft size was significantly larger in those with double scroll configuration (7.9 ± 0.2 mm) than in those without (7.4 ± 0.4, P = 0.03). There were no significant differences in other features and clinical outcomes, although unfolding-time was shorter in eyes with double scroll configuration (4.6 ± 2.0 min) compared to those without (8.6 ± 8.1, P = 0.21). Ex vivo experiments showed that unfolding time was significantly shorter in double scroll configuration (2.71 ± 0.49 min) than in single scroll (5.02 ± 0.79, P = 0.01). Conclusions A double scroll configuration within a glass tube can be obtained more frequently in larger DMEK grafts (8.0 mm in diameter), which may result in easier and faster DMEK procedures.

A Novel Technique for Donor Insertion and Unfolding in Descemet Membrane Endothelial Keratoplasty.

To describe a novel technique for insertion and unfolding of donor Descemet membrane (DM) scroll during DM endothelial keratoplasty (DMEK). DMEK was performed in 20 eyes. The donor DM scroll was loaded into a glass injector, and the fluid column was manipulated to achieve a double scroll configuration. After performing DM stripping and inferior iridectomy, an anterior chamber (AC) maintainer was placed in position. The glass injector was inserted into the AC and the tip rotated to ensure correct orientation of the DM scroll. After disconnecting the IV tubing from the AC maintainer, the donor DM scroll was delivered into the AC. Donor unfolding was performed using surface tapping techniques. An air bubble was injected under the graft to obtain a complete AC air fill. The outcomes of this surgical technique were analyzed. Donor DM insertion and unfolding were performed without any complications in all eyes. Double scroll configuration of donor DM in the injector could be achieved in 17 of 20 eyes (85%). A controlled delivery, maintaining correct scroll orientation, was possible in all eyes. Intraoperative duration from insertion to unfolding was 252.7 ± 45.4 seconds. A clear cornea was achieved in all eyes, with 75% of eyes (15/20) achieving corrected distance visual acuity of 20/20 or better, at average follow-up duration of 13.3 ± 1.3 months. Endothelial cell loss at 6 months follow-up was noted to be 16.7%. Partial donor detachment was noted in 2 eyes (10%), which resolved spontaneously. Our novel technique of donor DM insertion allows easy donor insertion and unfolding, thereby simplifying the DMEK procedure.

Non stripping descemet membrane endothelial keratoplasty in difficult cases: A case series

Endothelial keratoplasty (EK) has been increasingly used instead of penetrating keratoplasty (PK) in the management of post PK graft rejection. Both DSAEK and DMEK involve the surgical removal of the diseased host endothelial cell layer and Descemet's membrane (DM) (descemetorhexis) before transplantation, a technically challenging step, especially in post-PK eyes. Understandably, interest arose when non-stripping DMEK (nDMEK) was described in 2013, and recent studies suggested encouraging results without increased early postoperative failures or complications requiring rebubbling. The purpose of our series was to further study the feasibility and safety of nDMEK and to compare the results with traditional DMEK. This is a single center case series of 3 eyes which underwent nDMEK performed by experienced surgeons (C.P, A.M). Two eyes had nDMEK as a secondary procedure following a failed/rejected PK, while the third case underwent nDMEK on a virgin eye. Undiseased donor DM and a regular host endothelium were required to be eligible for nDMEK. The average change in CCT at last follow-up was -21.2% (±13.3). All required intracameral air injection (rebubbling) within the first few days, with a mean of 2.33 rebubblings per eye, the first one occurring at 6.33±2.52 days after surgery. Non-stripping DMEK surgery appears to be a feasible option, and results are satisfactory at mid to long term. However, in our series, the immediate postoperative period was marked by an increased rebubbling rate. While foreseeable particularly in high-risk cases, surgeons considering this technique should expect a higher risk of early rejection.

Outcomes of Descemet's membrane endothelial keratoplasty for congenital hereditary endothelial dystrophy

To report outcomes of Descemet's membrane endothelial keratoplasty (DMEK) in eyes with congenital hereditary endothelial dystrophy (CHED). The medical records of patients with CHED who underwent DMEK were retrospectively reviewed. Pre- and postoperative visual acuity, corneal thickness, corneal clarity, and graft survival, were analyzed, and intra- and postoperative complications were assessed. A total of 14 eyes of 8 patients were included. Surgery was performed at a mean age of 10±7years (range, 2-23). DMEK was successfully performed in all eyes, with 13 of 14 eyes (93%) maintaining a clear cornea at final follow-up (mean, 16.9±8.1months). Following surgery, corrected distance visual acuity improved from 0.9±0.3 logMAR (Snellen 20/158) to 0.4±0.2 (20/50), and pachymetry improved from 932±57μm to 642±93μm. Endothelial cell loss was 33%, and average cell counts were 1767±281cells/mm2 at final follow-up. Intraoperative aqueous misdirection occurred in both eyes of a 2-year-old child, requiring pars plana vitrectomy. Postoperative donor Descemet's membrane detachment occurred in 4 eyes. Rebubbling was performed in 3 eyes (21%); 1 eye had spontaneous reattachment. One eye (8%) had possible graft failure during follow-up, requiring repeat DMEK surgery. In our study cohort of eyes with CHED, DMEK was performed with good visual outcome. Rebubbling was necessary for donor reattachment in the early postoperative period in some cases.

Intrastromal Descemet Membrane Transplantation as a Potential Alternative to Bowman Layer Inlays in Eyes With Advanced Keratoconus.

Herein, we report the outcomes of intrastromal Descemet membrane (DM) transplantation in corneas with advanced keratoconus. Three eyes (three patients) showed advanced keratoconus. No eye underwent prior UV-cross-linking or any other ocular surgery. In all eyes, A donor DM was implanted into a mid-stromal pocket and clinical outcomes were evaluated up to 24 months after surgery. All procedures were uneventful. Up to 24 months postoperatively, the DM graft was well-positioned and barely visible within the recipient stroma; all corneas were clear. No eye showed signs of keratoconus progression throughout the follow-up. No changes were observed in uncorrected and best contact lens corrected visual acuity, central endothelial cell density, corneal thinnest point pachymetry, and maximum keratometry values. No early or late postoperative complications were observed. Intrastromal DM transplantation may be an alternative to intrastromal Bowman layer transplantation in advanced keratoconus, to postpone deep anterior lamellar or penetrating keratoplasty.

Intrastromal descemet membrane transplantation in eyes with advanced keratoconus

Background. To report the outcomes of intrastromal Descemet membrane (DM) transplantation in corneas with advanced keratoconus.
 Materials and methods. Three eyes of 3 patients presented with advanced, progressive keratoconus. None of the eyes had prior UV-crosslinking or any other ocular surgery performed. All eyes had a donor DM implanted into a mid-stromal pocket under local anesthesia, and clinical outcomes were evaluated at 12 months after surgery.
 Results. To the best of our knowledge, this is the first report of DM transplantation performed in cases of advanced keratoconus. At 12 months after surgery, the DM graft was well positioned and barely visible within the recipient stroma, and all corneas were clear. None of the eyes showed signs of keratoconus progression throughout the follow-up period. No significant changes were observed in uncorrected (UCVA) and best contact lens corrected visual acuity (BCLCVA), central endothelial cell density (ECD), corneal thinnest point (CTP) pachymetry, and maximum keratometry values (SimK and Kmax). No early or late postoperative complications were observed.
 Conclusions. Intrastromal DM transplantation may potentially be an alternative to intrastromal Bowman layer transplantation in eyes with advanced keratoconus, to postpone deep anterior lamellar or penetrating keratoplasty.

Appropriate stage of Descemet membrane removal during donor preparation in deep anterior lamellar keratoplasty.

To investigate the appropriate surgical stage for Descemet membrane (DM) removal during donor preparation in deep anterior lamellar keratoplasty (DALK). This study included 83 corneoscleral buttons that were used for DALK. The donor DM was removed randomly either before (group 1; 43 eyes) or after (group 2; 40 eyes) trephination. The time required for DM removal was recorded, and the geometric properties of cut buttons were evaluated after trephination. The intraoperative video recordings were reviewed to determine if the dissections were performed at the stroma-DM plane as it was intended. The time needed to remove the DM, the rate of correct dissection at the intended stroma-DM plane, and the roundness and precision of the donor cuts were compared between the groups. The two groups were comparable in donor characteristics, including age, quality of the tissue, and trephination size. Time spent to remove DM was significantly shorter in group 1 (68.9 ± 48.2s) than group 2 (117.7 ± 52.7s, P = 0.001). DM stripping was performed incorrectly in 2 corneas (4.7%) in group 1 and in 12 corneas (30%) in group 2 (P = 0.01). No difference was found between the groups in the roundness and precision of donor button cuts. DM removal before trephination did not detrimentally affect the geometric properties of punched donor tissues. When DM stripping was performed before trephination, the donor tissue was less traumatized and posterior graft surface was more likely to be regular; therefore, it is advisable to remove DM before trephination during donor preparation for DALK.

Therapieoptionen bei Endotheldekompensation nach Glaukomchirurgie

During the last few years, Descemet membrane endothelial keratoplasty (DMEK) has become first line surgical treatment for patients with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy. However, in eyes with previous trabeculectomy or implantation of a glaucoma drainage device, this surgical technique, where the diseased Descemet's membrane and endothelium are replaced by a lamella of donor Descemet's membrane and endothelium, may have some limitations. These include complications during surgery such as difficult unfolding of the graft in the presence of a glaucoma tube with a risk of an increased endothelial cell loss and problems after surgery like the loss of the air/gas tamponade in the anterior chamber through the opening of the trabeculectomy or the tube, with an increased risk of graft dislocation. The following review contains information on endothelial cell loss following different glaucoma operations, discusses the advantages and disadvantages of various keratoplasty techniques and gives some technical advice for improving the surgical technique.

Effective Tissue Layer Separation of Donor Cornea for DMEK by Fluid Injection Between Descemet Membrane and Corneal Stroma: Results of First Series of Operations

To evaluate clinical outcomes of Descemet Membrane Endothelial Keratoplasty (DMEK) using a novel hydro-separation of donor Descemet membrane (DM) endothelial graft with 6 months follow up. In this retrospective single-center; single surgeon cohort study, 16 consecutive eyes underwent DMEK or combined DMEK and cataract surgery with DMEK donor graft hydro-separation. The hydroseparation method used Ringer’s solution injected by a syringe with a flat end cannula between DM and corneal stroma to separate DMEK graft from donors’ cornea. Endothelial cell count, corrected and uncorrected distance visual acuities (CDVA, UDVA), corneal astigmatism and keratometric values were evaluated before and 6 months after the surgery. DMEK grafts were successfully hydro separated, without a membrane tear in all cases and successful adhesion to recipient corneas was achieved in all cases. Overall CDVA improved significantly (p < 0.0001) from preop.0.69 logMAR (0.45–0.92, 95%CI) to 0.1 logMAR (0.04–0.15) 6 months postop. However UDVA was slightly worse in cataract combined cases 0.38 logMAR (0.18–0.43) vs 0.3 logMAR (0.14–0.61) in DMEK cases at 6 months. Corneal astigmatism K2-K1 improved significantly (p=0.0137) from preop. mean 2.89 D (0.19–0.43) to 0.98 D (0.48–1.48) 6 months postop. Hydro-separation is fast and effective donor graft preparation method for DMEK. The DMEK using donor graft hydro-separation results in improved vision and induces a low amount of astigmatism at 6 months follow up. Further clinical data are needed to confirm the success rate and to explore optimization of the selection of IOLs in combined cataract cases

Descemet Membrane Endothelial Keratoplasty with Irregular-Edged Graft: A Salvage Method for Large Radial Graft Tears.

Large radial tears of donor Descemet membrane (DM) during the preparation of Descemet membrane endothelial keratoplasty (DMEK) grafts can make the trephination stage impossible because of small graft diameter. This results in irregular-edged grafts. In this study, we report two pseudophakic bullous keratopathy patients who underwent DMEK surgery with irregular-edged Descemet membrane (DM) grafts. Main outcome measures were preoperative and postoperative 1-, 3-, and 6-month best corrected visual acuity (BCVA), endothelial cell density (ECD) and central corneal thickness (CCT). Intraoperative and early postoperative complications were also evaluated. Both irregular-edged grafts were successfully implanted into the anterior chamber, unfolded, and attached to the posterior corneal stroma. Patients’ BCVA at 6 months was 1.0 (Snellen equivalent: 20/20) and 0.6 (Snellen equivalent: 20/32) respectively. Decrease in ECD at the last visit was 27% and 25%. CCT decreased from 723 μm and 850 μm to 530 μm and 523 μm, respectively. No intraoperative complications occurred except for the large radial Descemet membrane graft tears that developed during donor DM stripping. None of the cases needed a rebubbling procedure postoperatively. We have demonstrated that irregular-edged DM grafts can be successfully implanted for DMEK surgery with good clinical outcomes.

Graft detachment and rebubbling rate in Descemet membrane endothelial keratoplasty

Descemet membrane endothelial keratoplasty (DMEK) is a selective replacement of dysfunctional endothelium with healthy donor Descemet membrane and endothelium. Although the donor preparation and surgical methods still remain a challenge, DMEK is gaining popularity in terms of early rehabilitation and visual outcomes. New and improved donor preparation techniques like prestripped DMEK tissues are being taken up rapidly because of less manipulation that is required in the surgical theatre. Donor graft delivery in the recipient eye has also been improved because of new products like prestripped and preloaded membranes. As DMEK is at its budding stage, only early outcomes have been known so far. Early graft detachment, rebubbling rates, and primary failures are still being studied in DMEK. As there are different techniques that are currently used for preparation and injection of the graft, it becomes difficult to judge the results based on specific inclusion and exclusion criteria. Graft detachment and rebubbling rates have been a huge challenge both during the surgery and also while reporting postoperative data. We highlight the importance of defining graft detachment and rebubbling rates and their surgical relevance, which may also have an impact on graft preparation and insertion techniques.

“Salt and Pepper Endothelium” Recurring After Descemet Membrane Endothelial Keratoplasty

To describe the presence of "salt and pepper endothelium", that is, typical cellular inclusion bodies in a patient with Fuchs endothelial corneal dystrophy (FECD), that recurred in the donor corneal endothelial cells after Descemet membrane endothelial keratoplasty (DMEK). A 76-year-old man underwent DMEK for FECD in his left eye. Routine specular microscopy imaging, best-corrected visual acuity measurements, and pachymetry measurements were performed before and after surgery. Besides large guttae indicating FECD, preoperative specular microscopy images showed variable-sized dark cellular inclusion bodies in the endothelial cells. One month after DMEK, donor endothelial cells appeared normal; however, at 3 months, the typical inclusion bodies reappeared and progressed slowly within a 4-year follow-up period. Both best-corrected visual acuity and pachymetry were stable throughout the study period. "Salt and pepper endothelium" recurred after the host tissue was exchanged by donor Descemet membrane, that is, a DMEK graft. These changes may indicate that either the donor corneal endothelial cell morphology is modified by adjacent tissue structures or that it is completely replaced by recipient endothelium within the first months after surgery.

Relationship Between Tissue Unscrolling Time and Endothelial Cell Loss.

To assess the relationship between intraoperative unscrolling time of the donor Descemet membrane endothelial keratoplasty (DMEK) tissue and 6-month postoperative endothelial cell loss (ECL), and to determine whether donor age, scroll tightness, and the presence of an S stamp are related to unscrolling time. Ninety-three consecutive uncomplicated DMEK surgeries performed on eyes with Fuchs endothelial dystrophy using our standardized technique (ie, prestripped tissue with or without a premarked S stamp from our eye bank, overstripping the recipient, Straiko glass injector, no-touch tap technique, and bubble of 20% SF6 gas) were evaluated. Intraoperative unscrolling times and 6-month endothelial cell densities were measured and analyzed. Sixty-nine cases comprised the study cohort. The median unscrolling time was 4 minutes (range: 0.8-17.5 minutes), and the median ECL was 26.9% (range: -4.3% to 80.0%). There was no relationship between unscrolling time and ECL at 6 months by the Pearson correlation coefficient (r = -0.02, P = 0.89). Younger donor age, tighter scrolls, and absence of an S stamp had no correlation with longer unscrolling times (all P > 0.05). Only 2 of 4 cases of iatrogenic primary graft failure had unscrolling times available for analysis; in this limited sample, there was no association between iatrogenic primary graft failure and unscrolling time. Once the DMEK tissue is safely in the anterior chamber, surgeons need not rush the "DMEK dance" because longer unscrolling times may not endanger the endothelium.

Donor Descemet Membrane Preparation for Descemet Membrane Endothelial Keratoplasty (DMEK) – Review of current techniques

Compared to DSAEK, preparation of donor DM (Descemet membrane) is surgically challenging and has a steep learning curve. In this article we discuss the various techniques of harvesting donor DM for DMEK surgery which have evolved over the past nine years for better surgical outcome.

Corneal donor tissue preparation for Descemet's membrane endothelial keratoplasty.

Descemet's Membrane Endothelial Keratoplasty (DMEK) is a form of corneal transplantation in which only a single cell layer, the corneal endothelium, along with its basement membrane (Descemet's membrane) is introduced onto the recipient's posterior stroma(3). Unlike Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), where additional donor stroma is introduced, no unnatural stroma-to-stroma interface is created. As a result, the natural anatomy of the cornea is preserved as much as possible allowing for improved recovery time and visual acuity(4). Endothelial Keratoplasty (EK) is the procedure of choice for treatment of endothelial dysfunction. The advantages of EK include rapid recovery of vision, preservation of ocular integrity and minimal refractive change due to use of a small, peripheral incision(1). DSAEK utilizes donor tissue prepared with partial thickness stroma and endothelium. The rapid success and utilization of this procedure can be attributed to availability of eye-bank prepared precut tissue. The benefits of eye-bank preparation of donor tissue include elimination of need for specialized equipment in the operating room and availability of back up donor tissue in case of tissue perforation during preparation. In addition, high volume preparation of donor tissue by eye-bank technicians may provide improved quality of donor tissue. DSAEK may have limited best corrected visual acuity due to creation of a stromal interface between the donor and recipient cornea. Elimination of this interface with transplantation of only donor Descemet's membrane and endothelium in DMEK may improve visual outcomes and reduce complications after EK(5). Similar to DSAEK, long term success and acceptance of DMEK is dependent on ease of availability of precut, eye-bank prepared donor tissue. Here we present a stepwise approach to donor tissue preparation which may reduce some barriers eye-banks face in providing DMEK grafts.

Evidence of Donor Corneal Endothelial Cell Migration From Immune Reactions Occurring After Descemet Membrane Endothelial Keratoplasty

The migratory capacity of donor corneal endothelial cells after Descemet membrane endothelial keratoplasty (DMEK) is not fully understood. We report 2 patients who developed immune reactions after DMEK with endothelial precipitates detectable not only on the grafts but also on host corneal areas stripped off the host Descemet membrane during surgery and initially not covered by the donor Descemet membrane and endothelium ("naked stroma"), strongly suggesting that migration of donor-derived endothelial cells had occurred. Observational case series of 2 patients. A 71-year-old man (case 1) and an 84-year-old man (case 2) with Fuchs endothelial dystrophy underwent successful DMEK surgery. Postoperatively, the peripheral corneal stroma showed a denuded area that was not covered by the DMEK graft or by the patients' residual Descemet membrane (because of large descemetorhexis and slight graft decentration). After 18 (case 1) and 6 (case 2) months, a diffuse endothelial immune reaction with precipitates on the graft and, surprisingly, also on peripheral corneal areas that were initially denuded of the host Descemet membrane and not covered by the donor Descemet membrane was observed. The outermost corneal parts covered by the patients' own residual Descemet membrane showed no precipitates. Under treatment with topical corticosteroids, the precipitates rapidly disappeared. Visual acuity, central corneal thickness, and endothelial cell counts were not significantly affected. The immune reaction episodes in our patients with endothelial precipitates detectable on adjacent host areas initially stripped off and not covered by donor Descemet membrane provide direct in vivo evidence of donor corneal endothelial cell migration after DMEK, filling areas of "naked stroma."

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

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. 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. Transmission electron microscopy revealed close attachment of the donor's Descemet membrane to the host's stroma and projection of stromal collagen fibers into the interfacial matrix, resembling a normal "virgin" corneal architecture. Ultrastructurally, an attached Descemet membrane endothelial keratoplasty graft closely resembles that of an unoperated, healthy eye with no appreciable adventitious or missing structures.