Descemet Membrane Endothelial Keratoplasty Research Articles

Gonioscopy-assisted transluminal trabeculotomy as a primary surgical option for glaucoma in Fuchs uveitis syndrome: A case series.

Fuchs uveitis syndrome (FUS) is a chronic intraocular inflammatory disease. It can lead to glaucoma which can be intractable to both medical and surgical treatment. In the present report, we describe our experience with GATT as a primary surgical option in the treatment of glaucoma secondary to FUS. Four consecutive patients with FUS-associated glaucoma underwent GATT in a single institution. Case 1 was a 28-year-old pseudophakic male with a preoperative intraocular pressure (IOP) of 43 mmHg had unsuccessful circumferential cannulation; his IOP remained high after GATT and received trabeculectomy followed by Ahmed glaucoma valve (AGV) implantation to control IOP. Although IOP was stable following AGV, he required descemet membrane endothelial keratoplasty due to persistent corneal decompansation. He had a stable IOP of 12 mmHg over 21 months. Case 2 was a 42-year-old male with preoperative IOP of 35 mmHg and posterior subcapsular cataract had 360-degree GATT combined with phacoemulsification; his IOP reduced to 14 mmHg over 18 months. Case 3 was an 52-year-old pseudophakic male with a preoperative IOP of 28 mmHg had 360-degree GATT; his IOP remained stable at 10 mmHg over 18 months. Case 4 was an 47-year-old pseudophakic female with a preoperative IOP of 39 mmHg had 360-degree GATT; her IOP remained stable at 14 mmHg over 12 months. GATT may be used as an initial approach in secondary glaucoma due to FUS. But, further evidence is still warranted to better ascertain the usefulness of GATT in this specific patient population.

Descemet's membrane endothelial keratoplasty rejection after SARS-COV2 infection or vaccination: 2-year retrospective study

To assess the incidence of Descemet's membrane endothelial keratoplasty (DMEK) rejection potentially associated with coronavirus disease 2019 (COVID-19) infection or vaccination, and its association with known rejection risk factors during the first two years of the pandemic. This retrospective study included patients with DMEK rejection between January 2020 and December 2021. Diagnostic criteria were based on symptoms, visual acuity, and other clinical assessments. Risk factors for graft rejection were considered, and a telephone survey was conducted to identify possible preceding COVID-19 infection or vaccination. Of 58 patients, 44 were included. Six patients (14%) reported COVID-19 infection, with one immediate endothelial graft rejection (EGR) post-infection. After vaccine availability, 13 of 36 patients had EGR at an average of 2.7 months post-vaccination. Five (38%) had immediate EGR following vaccination, four of which had concomitant risk factors for rejection. Although the risk of endothelial graft rejection (EGR) associated with COVID-19 infection or vaccination appears to be extremely low, there may be a causative relationship, especially in patients with pre-existing risk factors for EGR. A temporary increase in anti-rejection treatment following COVID-19 infection or vaccination is recommended, especially in patients with pre-existing risk factors, along with closer monitoring during the subsequent 4 to 8 weeks.

3D Mapping of the DMEK Detachment Area from OCT Scans of the Anterior Segment of the Eye - Clinical Applications.

Graft detachment is the most common complication after Descemet membrane endothelial keratoplasty (DMEK). To assess the amount of graft detachment, precision is limited when using slit-lamp biomicroscopy. Detachment of DMEK grafts can be assessed automatically on anterior segment optical coherence tomography (AS OCT) images and allows visualization of the area and volume of detachment using 3D maps. This article provides an overview of its applications such as accurately assessing the course of natural graft attachment, identification of potential risk factors for detachment and evaluation of the long-term effect of graft detachment. The 3D map of DMEK detachment may support researchers and clinicians in precise quantification of the area and volume of graft detachment even in large data sets, and the intuitive, fast and reliable evaluation.

Retinal Detachment Rates After Uncomplicated DMEK Versus Cataract Surgery Combined (Triple-)DMEK.

To evaluate the rate of and risk factors for rhegmatogenous retinal detachment (RRD) after Descemet membrane endothelial keratoplasty (DMEK) either alone or in combination with cataract surgery. Retrospective analysis of prospective database. Consecutive eyes with Fuchs endothelial corneal dystrophy (FECD) that received DMEK surgery with a minimum follow-up of 1 year between July 2011 and January 2021 at the Department of Ophthalmology at the University of Cologne were analyzed. Exclusion criteria were complicated history including repeat DMEK within 1-year, previous retinal or glaucoma surgery, complicated phacoemulsification, congenital cataract, history of trauma. From 3858 consecutive DMEKs, 1961 patients were identified suitable for analysis. 846 (43.1%) were pseudophakic DMEK, 91 (4.6%) phakic DMEK and 1,024 (52.2%) combined with cataract surgery. RRD occurred in 13 eyes (12 patients). Within two years after DMEK RRD occurred in 0.49% and 0.47% after DMEK and DMEK with cataract surgery, respectively. Mean age of 59.24 ± 8.42 years with subsequent RRD was significantly lower than overall 68.81 ± 9.89 years (t-test two-tailed; p < 0.001). The spherical equivalent was -4.69 ± 3.98 D (range -9.00 to 0.5) in RRD after pseudophakic DMEK compared to -2.79 ± 3.54 D (range -7.5 to 0.75) in combined procedures. Re-bubbling had no influence on RRD rate. DMEK alone or in combination with cataract surgery showed similar postoperative RRD rates in the first two years, generally in the range of pseudophakic RRDs. Risk factors such as myopia and younger age could be identified. Re-bubbling has no influence on RRD rates.

“Treat and Extend” amphotericin B in post-op DMEK fungal endophthalmitis

Purpose: The purpose of this study was to describe a case of post DMEK-fungal endophthalmitis treated with “treat and extend” amphotericin B, a method not fully described in the literature. Methods: We conducted an extensive retrospective chart review to create this case report. Results: An 85-year-old female with a history of Descemet membrane endothelial keratoplasty (DMEK) and positive yeast growth in the donor tissue presented with clinical signs of endophthalmitis. The culture samples were positive for Candida glabrata, indicating fungal endophthalmitis. Amphotericin B was administered because of its strain’s resistance to azole-like medications. The patient was closely followed every month, then two months, then every ten weeks with persistence of infection with intermittent flare-ups and continues to receive amphotericin B to temporarily reduce ocular symptoms. Conclusions: “Treat and extend” with amphotericin B is an alternative method of care for post-DMEK fungal endophthalmitis with the goal of temporary resolution of symptoms and maintenance of vision.

Impact of the ratio between graft and host corneal size on immune rejection, re-bubbling rate and postoperative endothelial cell loss in 457 eyes after Descemet membrane endothelial keratoplasty (DMEK)

The aim of this study was to assess the impact of the ratio between the graft and host corneal size (RGH) on postoperative complications, such as immune reactions, re-bubbling rate and endothelial cell loss (ECL) after Descemet membrane endothelial keratoplasty (DMEK). Retrospectively, 457 patient eyes were included which had undergone surgery between 2016 and 2019 in the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar using DMEK or triple DMEK, diagnosed as Fuchs' endothelial dystrophy (n = 431), pseudophakic bullous keratopathy (n = 9) and others (n = 17). The follow-up period extended until the end of 2020.Main outcome measures included immune reaction (IR), re-bubbling rate and the postoperative endothelial cell loss (ECL) at 6weeks, 6months and 12months and whether these measures depended on the RGH. The RGH in this study ranged from 0.35 to 0.62 (0.46 ± 0.04). There were 33(7.2%) postoperative IRs (DMEK n = 25; triple DMEK n = 8). The average RGH without IR (0.46 ± 0.04) was significantly (p = 0.038) smaller than in the group with IR (0.47 ± 0.05). Re-bubbling was necessary in 159 of 457 (34.8%) patient eyes. The RGH in patient eyes with re-bubbling (0.47 ± 0.04) was significantly (p = 0.014) higher than that in eyes without re-bubbling (0.45 ± 0.04). The mean preoperative endothelial cell count (ECD) was 2603 ± 251 cells/mm2 (min: 2161, max: 3500 cells/mm2). It was shown that alarger RGH had no positive influence on endothelial cell loss (r = 0.001; p = 0.974). Our results suggest that alarger graft diameter compared to host corneal size is associated with an increased rate of immune reactions and ahigher re-bubbling rate after DMEK. Otherwise, alarger RGH had no positive influence on endothelial cell loss after DMEK. Accordingly, the graft size for DMEK should not be unnecessarily large, especially in eyes with Fuchs' endothelial dystrophy.

Unaddressed Factors and Their Role in DMEK Outcomes: Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty Using a Preloaded Imported Graft.

Unaddressed Factors and Their Role in DMEK Outcomes: Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty Using a Preloaded Imported Graft.

Descemet Membrane Endothelial Keratoplasty (DMEK) Anesthesia Analysis.

Comparison of safety and clinical results of Descemet membrane endothelial keratoplasty (DMEK) in topical, peribulbar, or general anesthesia. Retrospective, post hoc matched study of 346 patients who received DMEK surgery with different types of anesthesia (n = 54 topical, n = 137 peribulbar, n = 155 general anesthesia). Outcome criteria were intraoperative complications, endothelial cell count (ECC), central corneal thickness (CCT) and graft rejection rate, rebubbling rate, and visual acuity (VA). Mean follow-up time was 9.4 ± 2.8 months. The group with topical anesthesia showed intraoperative difficulties such as vitreous pressure (p = 0.01) and difficult graft unfolding (p = 0.4), possibly leading to a higher rebubbling rate (p = 0.03) and therefore graft failure (p = 0.39). However, rebubbling and graft failure occurred more often when the graft preparation was more difficult (p = 0.2, p = 0.13, respectively), which was independent of anesthesia. All three groups achieved comparable functional results regarding VA, ECC, and CCT after 6 months. DMEK under topical anesthesia is feasible and shows comparable final visual outcomes but should be limited to selected cooperative patients and performed by experienced surgeons due to the potential for increased intraoperative challenges.

Descemet Membrane Endothelial Keratoplasty for Penetrating Keratoplasty

ABSTRACT Background: Descemet membrane endothelial keratoplasty (DMEK) has been utilized more frequently during recent years to treat penetrating keratoplasty (PKP) graft failures. The perioperative evaluation technique of anterior segment optical coherence tomography (AS-OCT) is increasingly significant. Our goal is to discuss DMEK surgical and clinical for subsequent PKP graft failure, along with significant surgical modifications and adjustments in accordance with preoperative assessment utilizing AS-OCT. Materials and Methods: Patients’ records who performed DMEK for PKP failure were retrospectively reviewed. Demographic information, PKP graft size determined by postoperative problems, corneal donor endothelial cell density (ECD), AS-OCT, central pachymetry, visual acuity (VA) evaluated in Snellen units, intraoperative surgical procedure modifications, and postoperative ECD were all included in the data collection. Results: The observation was conducted with 16 patients with 16 eyes, nine males and seven females. The observation period is 18 months. DMEK was performed at an average age of 63. Preoperative AS-OCT was performed on all patients, and based on cases, surgical plans were created. Before processing DMEK, the mean VA is 0.04, and central pachymetry is 685 m. They improved considerably to 0.3 (P value = 0.001) and 542 m (P value = 0.008) at the most recent follow-up. About 93.75% of the grafts were adhered to after the procedure. Late decompensation caused a 6.25% graft failure rate. Graft detachment rates and cases requiring rebubble rates were respectively 18.75%. Conclusion: In DMEK for failed PKP, a good case-specific preoperative assessment by AS-OCT is essential. As a result, it relies on developing a surgical strategy that can improve surgical outcomes, lower the risk of complications, and quicken visual recovery.

Descemet Membrane Endothelial Keratoplasty With and Without Graft Deswelling: A Prospective Clinical Study.

The purpose of this study was to assess whether omission of dextran from corneal organ culture medium alters the outcome of Descemet membrane endothelial keratoplasty. Participation in this single-center, multisurgeon, prospective, randomized, comparative clinical trial was offered to patients scheduled for Descemet membrane endothelial keratoplasty between April 2020 and May 2022. Patients received grafts from corneas deswollen in organ culture medium-containing 6% dextran T-500 or from corneas that were not deswollen. Corrected distance visual acuity (CDVA), graft detachment, central corneal thickness (CCT), and corneal endothelial cell counts were measured at different time points up to 12 months postoperatively. Grafts stored with dextran were transplanted in 92 patients, and grafts stored without dextran were transplanted in 102 patients. Mean donor age and endothelial cell counts did not differ significantly between both groups. Mean (±SD) postmortem time in hours was 23.9 ± 11.8 in grafts that were deswollen and 28.2 ± 13.8 in grafts that were not deswollen (P = 0.02). The groups did not show any significant difference at baseline regarding sex, CDVA, or CCT. In the group with dextran, patients had a mean age of 72.5 ± 9.9 years versus 69.5 ± 8.7 in the group without dextran (P = 0.03). CDVA improved and CCT decreased significantly in both groups. No differences were detected between the groups regarding CDVA, CCT, endothelial cell counts, or rebubbling rates. This study did not detect any evidence that the omission of dextran from organ culture medium negatively affects the outcomes of Descemet membrane endothelial keratoplasty.

Analysis of Graft Detachments and Re-Bubblings After 450 Descemet Membrane Endothelial Keratoplasty Procedures.

To objectify the indication for re-bubbling by analyzing graft detachments (GDs) after Descemet membrane endothelial keratoplasty. In this retrospective monocentric observational study, re-bubbling cases of 450 Descemet membrane endothelial keratoplasties and the percentage of the residual gas filling (RGF) in the anterior chamber on the first postoperative day were collected. The number/location/extent of GDs and the corneal thickness above GDs were analyzed using anterior segment optical coherence tomography. From a total of 450 grafts, 384 (85.3%) had at least a minimal degree GD. One hundred twenty-two of 450 grafts (27.1%) underwent at least 1 re-bubbling. The mean RGF was significantly lower in eyes with GD (67.7 ± 12.6%) than in eyes without GD (74.2 ± 11.3%). GDs occurred most frequently in the inferotemporal quadrant (46.0%). GDs were significantly more likely to require a re-bubbling when the central parts of the graft were affected (94.0% vs. 35.7%). The number of detachments per graft was directly proportional to the re-bubbling rate. The GDs which required a re-bubbling were on average 56 μm higher and 461 μm wider than the untreated ones. The cornea above the GDs that needed a re-bubbling was significantly thicker than above the untreated GDs (mean 988 ± 102 μm vs. 951 ± 99 μm). The RGF seems to be a major influencing factor for graft attachment. The most susceptible location of the GD is inferotemporal. The main factors that need to be investigated to decide if a re-bubbling is required are the number of detachments per graft, their dimensions, whether the central portions of the graft are involved, and the corneal thickness above GDs.

Effects of graft detachment on the central corneal thickness after uncomplicated Descemet membrane endothelial keratoplasty.

To determine if early central corneal thickness (CCT) and best-corrected visual acuity (BCVA) changes indicate graft detachment after uncomplicated Descemet membrane endothelial keratoplasty (DMEK). In this analysis of our prospectively collected ADDA registry data ( https://drks.de/search/de/trial/DRKS00027180 ), 45 pseudophakic eyes underwent DMEK surgery at the Department of Ophthalmology, RWTH Aachen University. Anterior segment optical coherence tomography (AS-OCT), the presence of stromal ripples on the posterior corneal surface, and BCVA measurements were assessed prior to, 1day, 1week, 1month, and 6months after surgery. Eyes were categorized into three groups: no graft detachment (group 1) (20/45; 44.4%), < 1/3 graft detachment (group 2) (14/45; 31.1%), ≥ 1/3 graft detachment followed by rebubbling (group 3) (11/45; 24.4%). Eyes in group 3 had a greater CCT prior to (746.8 ± 95.8µm vs. 665.0 ± 74.4µm, P = 0.041), and 1week (666.8 ± 119.5µm vs. 556.5 ± 56.8µm, P = 0.001) after DMEK compared to group 1. By 1month, CCT in all groups aligned. Comparing prior to and 1week after DMEK, none of the eyes in group 1 had an increase in CCT, while the CCT increased in 25.0% of eyes in group 2 and 22.2% in group 3. In group 1, 90.0% had a CCT of < 600µm 1week after DMEK, compared to only 50.0% in group 2 and 36.4% in group 3. In group 1, 90.0% (18/20) had an improved BCVA 1week after DMEK, while in groups 2 and 3, 86.7% (12/14) and 18.2% (2/11) improved, respectively. One patient in group 3 showed posterior stromal ripples 1day and 1week after DMEK. If 1week after uncomplicated DMEK CCT is < 600µm and has decreased from before surgery, BCVA has improved, and there are no posterior stromal ripples, a graft detachment ≥ 1/3 and the need for rebubbling are very unlikely. In all other cases, meticulous slit-lamp and OCT inspection of the peripheral graft for detachments should be advised.

Epithelial ingrowth in descemet membrane endothelial keratoplasty associated with vitreous loss

BackgroundEpithelial ingrowth is a rare but potentially sight-threatening complication caused by the invasion of corneal or conjunctival epithelial cells into the eye during ocular surgeries. DMEK is emerging as a widely used surgery for endothelial keratoplasty with its improved safety profile. We describe a case of epithelial ingrowth in the graft-host interface after uneventful DMEK associated with vitreous prolapse in the anterior chamber.Case presentationAn 81-year-old female with Fuchs endothelial dystrophy underwent DMEK for corneal decompensation following cataract surgery. During the DMEK procedure, vitreous prolapse was observed around the intraocular lens (IOL). Her early postoperative course was unremarkable, but a dense paracentral interface opacity was observed during the 3-month follow-up. The area of epithelial ingrowth was imaged with optical coherence tomography (OCT) as a uniform nodule with a discrete increase in interface hyperreflectivity. A low-energy YAG laser was applied to remove the opacity. She maintained good vision and clear cornea without reoccurrence after treatment.ConclusionsWe propose that, in addition to the introduction of epithelial cells during surgery, vitreous retention in the anterior chamber may be a risk factor by providing a scaffold that potentially aggravates epithelial ingrowth in DMEK. Our case demonstrated that early YAG intervention may disrupt interface epithelial cell growth, and the transmitted laser energy may fragment the scaffold vitreous noninvasively.

Machine learning based endothelial cell image analysis of patients undergoing descemet membrane endothelial keratoplasty surgery.

In this study, we developed a machine learning approach for postoperative corneal endothelial cell images of patients who underwent Descemet's membrane keratoplasty (DMEK). An AlexNet model is proposed and validated throughout the study for endothelial cell segmentation and cell location determination. The 506 images of postoperative corneal endothelial cells were analyzed. Endothelial cell detection, segmentation, and determining of its polygonal structure were identified. The proposed model is based on the training of an R-CNN to locate endothelial cells. Next, by determining the ridges separating adjacent cells, the density and hexagonality rates of DMEK patients are calculated. The proposed method reached accuracy and F1 score rates of 86.15 % and 0.857, respectively, which indicates that it can reliably replace the manual detection of cellsin vivoconfocal microscopy (IVCM). The AUC score of 0.764 from the proposed segmentation method suggests a satisfactory outcome. A model focused on segmenting endothelial cells can be employed to assess the health of the endothelium in DMEK patients.

Plastic vs. glass: the effect of the synthetic material in contact with DMEK tissue during staining on endothelial cell loss.

Endothelial cell loss (ECL) during Descemet membrane endothelial keratoplasty (DMEK) graft preparation has been shown to affect graft survival and the need for re-grafting. The purpose of this study was to quantitatively assess the impact of the plastic and glass mediums in contact with DMEK donor tissue during intra-operative graft staining on ECL. Retrospective study that included patients who underwent DMEK surgery between January 2019 and June 2021 at Hôpital Maisonneuve-Rosemont and the Jewish General Hospital in Montreal, Canada. DMEK grafts were stained with 0.06% Trypan blue ophthalmic solution (VisionBlue®, Dutch Ophthalmic, USA, Exeter, NH) for 120s in either a plastic or glass medium prior to delivery into the recipient's eye. The ECL was compared between the two groups 12-30months post-operatively. ECL at 12-30months was significantly less in the eyes that had received grafts stained in a plastic medium compared to those stained in a glass medium. Graft survival and re-bubbling was higher in the glass group however this difference was not statistically significant. Staining of the DMEK graft in a plastic medium caused less ECL compared to the glass medium.

Descemet Membrane Endothelial Keratoplasty as Treatment for Late-Onset Interface Fluid Syndrome After Laser In Situ Keratomileusis.

We herein present Descemet membrane endothelial keratoplasty (DMEK) as an effective surgical means of treatment for the management of interface fluid syndrome (IFS) in a series of cases with distant history of laser in situ keratomileusis (LASIK). Three cases from a single institution were included. All patients had documented IFS in the setting of history of LASIK. All 3 patients underwent DMEK for the treatment of IFS. Visual acuity, clinical findings, pachymetry, endothelial cell count, and anterior segment optical coherence tomography were recorded. We describe 3 cases of late-onset IFS that developed in eyes many years after LASIK (ranging from 15 to 31 years). All 3 patients had clinically significant corneal edema and evidence of poor endothelial function at the time of IFS diagnosis. DMEK was subsequently performed in each case. All 3 eyes showed resolution of corneal edema and improvement in best-corrected visual acuity after DMEK. DMEK can provide successful visual and anatomical recovery in patients who have had previous LASIK and experience late-onset IFS due to endothelial cell dysfunction.

Double-Bubble Technique Assisted by Holding Forceps: A Modified Technique in Descemet Membrane Endothelial Keratoplasty for Vitrectomized Eyes With Scleral Fixated Intraocular Lens.

Several techniques have been developed for graft unfolding approaches in Descemet membrane endothelial keratoplasty (DMEK). However, despite these techniques, graft deployment and configuration in eyes with deep anterior chambers remain challenging in some cases. Therefore, in this study, we described a modified technique for DMEK, known as the "double-bubble technique assisted by holding forceps." This was a retrospective interventional case series. Patients who underwent DMEK between August 2022 and July 2023, including cases with a history of vitrectomy and scleral fixation of intraocular lens, were enrolled in this study. Two experienced surgeons performed DMEK. In brief, after graft insertion into the anterior chamber, the first bubble with a small volume of air was injected above the graft to open the tight roll, and the graft edge was held using a 25-gauge graft manipulator. The second bubble was injected underneath the graft for fixation, while the graft edge was grasped using forceps during gas injection. The graft was released from the forceps. Best spectacle corrected visual acuity, central corneal thickness, endothelial cell density, and incidence of postoperative complications were measured before and after DMEK. Eleven eyes of 11 patients were included in this study (mean follow-up period, 4.5 ± 4.4 months). Best spectacle corrected visual acuity and central corneal thickness significantly improved postoperatively ( P < 0.001). Rebubbling was required in 2 eyes; no other postoperative complications or primary graft failure were observed. The present technique enables safe and feasible DMEK surgery in vitrectomized eyes with scleral fixated IOLs and in those with a deep anterior chamber.

Donor Characteristics in Graft Detachment after Posterior Lamellar Keratoplasty for Fuchs Endothelial Dystrophy and Bullous Keratopathy.

Background: Descemet Membrane Endothelial Keratoplasty (DMEK) has been widely adopted to treat Fuchs endothelial dystrophy (FED) and Bullous keratopathy (BK). Graft detachment (GD) is one of the common earliest post-operatory complications, and it is usually recovered by Air Rebubbling (ARB). Methods: Retrospectively, we investigated predictive factors related to GD between January 2016 and March 2020, a pre-COVID era, in 72 patients, 72 eyes, and their donors' lamellar characteristics, focusing on donor's cause of death. The patients were divided according to the posterior lamellar keratoplasty technique adopted. Results: GD and consequent ARB were most common but not significantly prevalent in DMEK (p = 0.11). It was more common in FED for both surgical approaches. Only in BK treated with DSAEK were host steeper mean astigmatism (p = 0.03) and donors with smaller graft pre-cut diameters (p = 0.02) less likely to be related to GD. Regarding donor's cause of death, only cardiovascular accident could be related to GD in BK treated with DMEK (p = 0.04). Conclusions: Our study shows that the conventional match between pathology and corneal lenticule is not sufficient to prevent ARB. Donor's cause of death can impair graft and host attachment. In particular, cardiovascular death may impair the efficiency of donors' endothelial cells, inducing GD after DMEK in BK.

Comparison of immunogenic and crystalline endothelial deposits after Descemet membrane endothelial keratoplasty(DMEK)-areport of two cases

Comparison of immunogenic and crystalline endothelial deposits after Descemet membrane endothelial keratoplasty(DMEK)-areport of two cases

Validation of preloaded DMEK donor tissues: a laboratory-based study on endothelial cell viability and comparison of two F-mark inks

ObjectiveTo investigate endothelial cell loss (ECL) associated with Descemet membrane endothelial keratoplasty (DMEK) donor tissues preloaded in the DMEK RAPID transport system after 1 and 5 days and to compare prestamping with 2 different F-mark inks. MethodsDMEK donor tissues were stripped, marked with gentian violet dye applied as an F-mark, trephined, stained with trypan blue, and then preloaded into the DMEK RAPID transport system by an eye bank technician. Preloaded DMEK tissues were then unfolded and stained with calcein AM after 1 or 5 days of storage. Tissues were imaged, analyzed for total tissue ECL, and immunostained for corneal endothelium markers zonular occludens-1 and xCD166. Additionally, ECL and the intensity of an F-mark caused by 2 different inks were quantified. ResultsPreloaded DMEK tissues displayed an average ECL of 11.9% ± 4.5% (n = 8) at 1 day and 9.9% ± 4.2% (n = 9) at 5 days. No difference was found between the 2 groups. Zonular occludens-1 and activated leukocyte cell adhesion molecule (ALCAM; also know as CD166) staining showed that the corneal endothelial monolayer remained intact on preloaded tissues. On 5-day preloaded DMEK tissues, the average ECL and mean grayscale caused by the Keir Surgical ink F-mark and the Cardinal Health ink F-mark were 4.3% ± 0.8% and 158.5 ± 13.9% and 5.0% ± 1.1% and 142.9% ± 20.0%, respectively. No difference was found between the F-mark inks. ConclusionPreloaded DMEK donor tissues resulted in an acceptable ECL range after 1 and 5 days of storage and were deemed suitable for transplantation. Both F-mark inks are acceptable for prestamping preloaded DMEK tissues prior to surgical transplantation with comparable ECL and intensities.