Descemet Membrane Endothelial Keratoplasty Surgery Research Articles

Pathogenesis of Fuchs endothelial corneal dystrophy, the fibrillar layer and individualized treatment

Fuchs endothelial corneal dystrophy (FECD) is agenetic and age-associated corneal disease characterized by an accelerated loss of corneal endothelial cells and an increased subendothelial deposition of extracellular matrix (ECM). Clinically, advanced disease leads to corneal edema with subsequent reduction in visual acuity. In the majority of patients with advanced FECD, afibrillar layer (FL) appears on the posterior corneal surface. This FL is mostly localized in the inferotemporal corneal quadrant, marks areas with significantly reduced endothelial cell density and increased corneal thickness in the sense of edema and can be visualized and measured using Scheimpflug backscatter analysis due to increased backscatter. FECD is currently the most common indication for corneal transplantation worldwide, usually in the form of Descemet membrane endothelial keratoplasty (DMEK). New treatment approaches include variations of DMEK surgery such as hemi- or quarter DMEK with individualized and smaller grafts or Descemet membrane stripping only (DSO). In the future, clinical imaging of the FL as aparticularly affected endothelial area could be important for FECD progression assessment and planning of surgical interventions. This article provides an overview of the current state of research on the clinical aspects, pathogenesis, fibrillar layer and individualized treatment of FECD.

Novel Trephine for Descemet Membrane Endothelial Keratoplasty Surgery Improves Surgical Preparation Time and Graft Quality: Pilot Data From the "Number 7" Endothelial Keratoplasty Trephine.

To report the safety and efficacy of a novel asymmetric marking trephine for Descemet membrane endothelial keratoplasty (DMEK) tissue preparation. The trephine design incorporates optimized curves to distribute mechanical forces and minimize the risk of tears without loss of total endothelial cell volume transplanted compared with a standard 8.00 mm circular transplant. A retrospective case series of 40 consecutive DMEK operations comparing 20 cases using the "Number 7" trephine against 20 using a modified shark fin technique as standard. Patient and donor characteristics, tissue preparation time and complications, total surgical time, intraoperative and postoperative complications, and endothelial cell counts at 3 months postsurgery are reported. DMEK tissue preparation was significantly faster using the "Number 7" trephine (5.4 vs. 7.6 minutes, P = 0.008). Further, fewer complications arose during tissue preparation (0 vs. 2 complications) despite the faster preparation time. Total surgical time was similar between techniques; however, time spent manipulating the graft was reduced (5.1 vs. 6.8 minutes, P = 0.007) primarily because of the lower tissue preparation complications. Fewer postoperative complications were observed (1 vs. 3, of which 1 in the standard technique group requiring a redo-DMEK), again due to the reduced tissue preparation complications. The 3-month endothelial cell count was comparable between techniques (P > 0.05). Use of the "Number 7" trephine led to faster and safer DMEK tissue preparation, which in turn reduced graft manipulation times and postoperative complications without compromising total endothelial cell volume transplanted. This novel device is ideal for use by surgeons who prepare their own DMEK tissue and within tissue banks who provide prestripped and preloaded DMEK tissue.

Comparison of rebubbling rate between preloaded endothelium-in and preloaded no-touch endothelium-out Descemet membrane endothelial keratoplasty transplantation

BackgroundTo compare the difference in rebubbling rates between patients undergoing Descemet membrane endothelial keratoplasty (DMEK) with endothelium-in using a standard IOL cartridge and those with endothelium-out DMEK utilizing a no-touch technique with borosilicate glass cartridge transplantation.MethodsThis retrospective study included all eyes that underwent preloaded endothelium-in or endothelium-out DMEK transplantation from June 2019 to December 2023 at the Hanusch Hospital, Vienna, Austria. All DMEKs were harvested, prepared and preloaded at the European Eye Bank of Venice, Italy. DMEK surgeries were done by one experienced surgeon and the procedure was completed by air tamponade of the anterior chamber.ResultsOverall, 32 eyes each of 31 endothelium-out patients and of 29 endothelium-in patients were included. 32 preloaded endothelium-in procedures were followed by 32 preloaded endothelium-out procedures. Rebubbling rate for endothelium-in was 15/32 (47%) and for endothelium-out was 7/25 (28%) (p = 0.035, Pearson’s chi-squared test). Donor age was the most important variable for rebubbling in a random forest algorithm model (ROC: 0.69).ConclusionsRebubbling rate in endothelium-out DMEK was less than two-thirds compared to endothelium-in DMEK favoring no-touch endothelium-out DMEK as the preferred technique of DMEK transplantation.

Descemet Membrane Endothelial Keratoplasty for Endothelial Failure in Primary Angle Closure Suspects.

To analyze the feasibility and outcome of Descemet membrane endothelial keratoplasty (DMEK) for treatment of endothelial failure in primary angle closure suspect (PACS) eyes. Retrospective, single-center case series of eyes treated by DMEK for endothelial failure caused by PACS. Main study parameters were success rate of DMEK, best-corrected visual acuity, anterior chamber depth, central corneal thickness, and endothelial cell density. Mean follow-up time was 16 ± 13 months. Ten eyes of 9 patients receiving DMEK for the treatment of corneal endothelial failure because of PACS were included. Except for 2 eyes that had undergone cataract surgery, none of the eyes had previous ocular surgery. DMEK combined with cataract surgery was performed in 5 eyes, DMEK alone with second-step cataract surgery in 2 eyes. The eyes with corneal edema after cataract surgery received DMEK only. DMEK surgery was successful in nine out of 10 eyes, 1 patient required repeat DMEK because of primary graft failure. In the group of phakic eyes, mean preoperative internal anterior chamber depth was 1.74 ± 0.18 mm. In eyes with corneal edema, central corneal thickness was 849 ± 205 μm before DMEK surgery, and 517 ± 24 μm at the final postoperative visit (P = 0.002). DMEK is a feasible option in eyes with endothelial failure because of primary angle closure. In case of advanced corneal edema, a second-step procedure (first DMEK, second cataract surgery) is a possible approach if visibility of the lens is too poor for simultaneous cataract surgery.

Predicting Success in Descemet Membrane Endothelial Keratoplasty Surgery Using Machine Learning.

This study aimed to predict early graft failure (GF) in patients who underwent Descemet membrane endothelial keratoplasty based on donor characteristics. Several machine learning methods were trained to predict GF automatically. To predict GF, the following variables were obtained: donor age, sex, systemic diseases, medications, duration of stay in the intensive care unit, death-to-preservation time (DPT), endothelial cell density of the cornea, tightness of Descemet membrane roll during surgery, anterior chamber tamponade, tamponade used for rebubbling, and preoperative best corrected visual acuity. Five classification methods were experimented with the study data set: random forest, support vector machine, k-nearest neighbor, RUSBoosted tree, and neural networks. In holdout validation, 75% of the data were used in training and the remaining 25% used in testing. The predictive accuracy, sensitivity, specificity, f-score, and area under the receiver operating characteristic curve of the methods were evaluated. The highest classification accuracy achieved during the experiments was 96%. The precision, recall, and f1-score values were 0.95, 0.81, and 0.90, respectively. Feature importance was also computed using analysis of variance. The model revealed that GF risk was related to DPT and the intensive care unit duration (P < 0.05). No significant relationship was found between donor age, endothelial cell density, systemic diseases and medications, graft roll, tamponades, and GF risk. This study shows a strong relationship between increased intensive care duration, DPT, and GF. Experimental results demonstrate that machine learning methods may effectively predict GF automatically.

DMEK Surgery at a Tertiary Hospital in Sweden. Results and Complication Risks.

This study reports clinical outcomes up to 6 years after Descemet's membrane endothelial keratoplasty (DMEK) performed at the Department of Ophthalmology, Örebro University Hospital, Örebro, Sweden. The study has a cross-sectional and case series design. Inclusion criteria were all DMEK-operated eyes during 2013-2018 until repeat keratoplasty. Altogether 162 eyes from 120 patients were enrolled. Among eyes without preoperative comorbidities, examined 1-6 years after DMEK, 85.8% achieved visual acuity of 0.1 logMAR or better. The median endothelial cell density (ECD) loss was 27% in a cohort of eyes examined 1-2 years post-DMEK, 31% at 2-3 years, 42% at 3-4 years, and > 60% at 4-6 years post-DMEK. ECD at the examination timepoint was correlated with donor ECD (as expected) and time since surgery. The results from DMEK surgeries in Örebro, Sweden, are promising. Further studies with even longer follow-up are needed to evaluate graft sustainability.

Descemet membrane endothelial keratoplasty and penetrating keratoplasty in pseudophakic bullous keratopathy: comparison of visual outcomes, graft survival rates, and complications

Objective: To compare the outcomes of Descemet Membrane Endothelial Keratoplasty (DMEK) and Penetrating Keratoplasty (PK) in patients with pseudophakic bullous keratopathy (PBK). Methods: Records of 51 eyes of 51 PBK patients (32 male, 19 female) who underwent PK (Group1=38 eyes) and DMEK (Group 2=13 eyes) were reviewed retrospectively. The two groups were compared for Best-corrected visual acuity (BCVA), graft survival rates, and complications. Results: The mean age was 69.1 and 67.1 years in group 1 and group 2, respectively. First-year cumulative survival rates for group 1 and group 2 were 92.1% and 61.5%, respectively, and 89.1% and 51.3% in the second year (P=0.001 by log-rank test). At the last follow-up visit, 2.7% of Group 1 and 30.8% of Group 2 had a BCVA of 0.3 or better (P=0.004). Graft failure was observed in 12 eyes (31.6%) in group 1 and 8 eyes (61.5%) in group 2 (P=0.056). At the last examination, the rates of transparent grafts were 73.7% and 69.2% in group 1 and group 2, respectively (P=0.756). Postoperative glaucoma was observed in 4 eyes (30.8%) in the group 2 and 4 eyes (10.5%) in the group 1 (P=0.083). There was no significant difference between the two groups regarding other complications (P&gt;0.05). Conclusions: DMEK surgery offers a better visual outcome than PK for the treatment of PBK. Careful follow-up of patients is required in terms of glaucoma and graft failure after DMEK. Although the graft survival rate was lower in the DMEK group, a similar rate of graft transparency was achieved at the final examination with repeated DMEK surgery.

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.

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.

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

PurposeTo determine if early central corneal thickness (CCT) and best-corrected visual acuity (BCVA) changes indicate graft detachment after uncomplicated Descemet membrane endothelial keratoplasty (DMEK).MethodsIn 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, 1 day, 1 week, 1 month, and 6 months after surgery.ResultsEyes 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 ± 95.8 µm vs. 665.0 ± 74.4 µm, P = 0.041), and 1 week (666.8 ± 119.5 µm vs. 556.5 ± 56.8 µm, P = 0.001) after DMEK compared to group 1. By 1 month, CCT in all groups aligned. Comparing prior to and 1 week 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 < 600 µm 1 week 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 1 week 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 1 day and 1 week after DMEK.ConclusionIf 1 week after uncomplicated DMEK CCT is < 600 µm 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.

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.

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.

Enhanced Monofocal Intraocular Lenses in Fuchs' Endothelial Dystrophy Patients: Results from Triple Descemet Membrane Endothelial Keratoplasty Procedure.

Descemet membrane endothelial keratoplasty (DMEK) is currently regarded as the most effective surgical procedure for addressing Fuchs Endothelial Corneal Dystrophy (FECD), frequently performed in conjunction with cataract surgery. In this retrospective study, we present a comparison of visual performance, clinical outcomes, and optical quality between two types of monofocal Intraocular Lenses (IOLs): one standard and one enhanced intermediate vision model, implanted in patients who underwent combined phacoemulsification and DMEK surgery. This single center comparative retrospective study was conducted at the Eye Clinic of the University of Florence (Italy) and included a total of 48 eyes of 48 patients affected by FECD and cataract. All patients underwent combined DMEK with phacoemulsification procedures. The patients' data were analyzed and divided into two groups: one group (standard group) consisted of 24 eyes that underwent phaco-DMEK with implantation of a monofocal IOL, and the second group (enhanced monofocal group) included 24 eyes that underwent phaco-DMEK with implantation of an enhanced monofocal IOL. In both groups, the following monocular visual outcomes were evaluated 6 months after surgery: Uncorrected Distance Visual Acuity (UDVA) and Best-Corrected Distance Visual Acuity (BCDVA) at 4 mts; Uncorrected Intermediate Visual Acuity (UIVA), Distance-Corrected Intermediate Visual Acuity (DCIVA) at 66 cm; Uncorrected Near Visual Acuity (UNVA) and Best Corrected Near Visual Acuity (BCNVA). Monocular defocus curves were also assessed. Furthermore, optical quality in terms of Contrast Sensitivity (CS) in photopic conditions, Higher-Order Aberrations (HOAs) at a pupil size of 5 mm. Modulation Transfer Function (MTF), Objective Scatter Index (OSI), and Strehl ratio, were also analyzed. A Patient-Reported Spectacle Independence Questionnaire was revised to evaluate spectacle independence outcomes. the two groups did not exhibit statistically significant differences in terms of UDVA, BCDVA, UNVA and BCNVA, photopic CS, HOAs, OSI, Strehl ratio, and MTF. However, in the phaco-DMEK enhanced monofocal IOL group, significantly better results were observed in terms of UIVA and DCIVA as well as a different defocus curve profile at 1.50 D, providing better defocus results at intermediate distance compared with the ZCB00 IOL. In our study, we found that enhanced monofocal lens performed favorable visual outcomes, even in cases of FECD, compared to standard monofocal IOLs. Comparable optical quality observed in the Eyhance group could allow surgeons to consider these lenses as a viable option for selected patients with FECD.

Re-descemet membrane endothelial keratoplasty (DMEK) with preservation of the original graft after free roll in anterior chamber: A case report

IntroductionLamellar keratoplasties have had a great impact in the management of corneal edema due to endothelial dysfunction. Minimally invasive transplant techniques such as Descemet Membrane Endothelial Keratoplasty (DMEK) have helped to reduce the morbidity involved in performing penetrating keratoplasty in this type of patient. Even so, these are complex techniques that are not free of complications and require a long line of surgical learning and an even more demanding experience in postoperative management. Clinical caseAn 89-year-old woman suffering from Fuchs endothelial dystrophy and undergoing combined cataract and DMEK surgery presented stromal edema predominantly inferior and sectoral detachment of the graft 24 h after the intervention. After re-bubbling in consultations and 4 days later, the graft was observed rolled and free in the anterior chamber.She underwent re-DMEK with preservation of the original graft after 24 h, with de-epithelialization to optimize visualization. The graft was stained with trypan blue and the posterior stroma was protected with air. The graft was reimplanted under intraocular maneuvers and with an air bubble.24 h after surgery, the adhered graft was observed, with a great decrease in stromal edema. One month later, the patient had a clear cornea, persistent complete graft adhesion, and visual acuity of 0.9. ConclusionThe discovery of free roll in the anterior chamber after DMEK surgery constitutes the most complex form of graft detachment. Corneal edema as well as the arrangement of the different intraocular structures are conditions to be considered for the surgical resolution of this complication. In many cases, surgical repositioning of the graft is feasible, which means saving costs without the need to use new donor corneal tissues.

Evaluating the forces involved in bubble management in DMEK surgery: mathematical and computational model with clinical implications.

To model postoperative forces involved in Descemet membrane endothelial keratoplasty (DMEK) tissue adherence and bubble management, including the impact of surface tension on graft support, with a view towards clinical applications. Tennent Institute of Ophthalmology, Glasgow, and James Watt School of Engineering, University of Glasgow, Glasgow, United Kingdom. Mathematical modelling and computer simulation. Theoretical modelling of biphasic flow and interaction of gas, liquid and tissue within the anterior chamber for static horizontal scenario A (adherent DMEK with mobile bubble) and dynamic vertical scenario B (release of bubble due to pupil block following DMEK). The model assumed incompressibility for both fluids within realistically achievable pressure ranges. Cahn-Hilliard Navier-Stokes equations were discretised through the application of the Finite Element Method. Mathematical modelling and computer simulation showed bubble size, corneal curvature and force intensity influences surface tension support for DMEK tissue in scenario A. Scenario B demonstrated complex, uneven distribution of surface pressure on the DMEK graft during uncontrolled bubble release. Uneven pressure concentration can cause local tissue warping, with air/fluid displacement via capillary waves generated on the fluid-air interface adversely impacting DMEK support. We have quantitatively and qualitatively modelled the forces involved in DMEK adherence in normal circumstances. We have shown releasing air/gas can abruptly reduce DMEK tissue support via generation of large pressure gradients at the liquid/bubble/graft interfaces, creating negative local forces. Surgeons should consider these principles to reduce DMEK graft dislocation rates via optimised bubble size to graft size, longer acting bubble support and avoiding rapid decompression where possible.

Surgery after corneal grafts

There is one available donor per 70 patients so we need to identify those whose vision would benefit from corneal transplantation and minimize risks that could jeopardize corneal graft survival possibility1.The two leading causes of graft failure post Penetrating Keratoplasty (PKP) are graft rejection and secondary glaucoma development. The existence of preoperative glaucoma increases two to three times the chances of graft rejections in any corneal transplantation2,3. The 10‐year Cornea Donor Study also confirmed that pre‐existing glaucoma is a risk factor for graft failure4. The 3‐year graft survival rate has been shown to be 71% in patients with preop glaucoma and 89% in patients without preop glaucoma5.In cases following Descemet Striping Endothelial Keratoplasty (DSAEK), Ocular Hypertension (OHT) ranges in otherwise healthy eyes from 29 to 47% and increases to 43 to 54% in cases with pre‐existing glaucoma or high‐risk eyes. Glaucoma can be presented in up to 15% in post‐DSAEK cases which increases twice the relative risk of rejection. Concurrent gonio‐synechiolysis is considered an additional risk factor whereas 18.6% of high IOP cases considered as secondary to steroid administration. Acute raise in IOP can be attributed in pupillary block at an estimated rate of 13%6,7.In cases of Descemet Membrane Endothelial Keratoplasty (DMEK) OHT or intraocular pressure (IOP) elevation is presented to 6.5 up to 11.1% and de novo glaucoma can be found from 2.8 to 6.5%, whereas progression of pre‐existing glaucoma is less than 2.5%8. In cases with simultaneous DMEK and cataract surgery there is greater likelihood of post‐op OHT or glaucoma. In DMEK cases the early postoperative increase in pressure is usually due to a combination of anterior (inferior) and posterior (superior) pupillary blocks when patient is sitting upright9.The late post‐DMEK IOP increase is attributed to Blockage of TM by inflammatory cells, PAS formation or steroid use. However, steroid‐induced glaucoma post‐DMEK is not as common as that in post‐PKP or post‐DSAEK due to the shortest steroid regime post‐DMEK cases. Treatment methods include medical treatment, trabeculectomy or tubes. Some cases with Xen®10 and Micropulse cyclodidode11 laser have been reported in endothelial cases, however with little degree of evidence.Controversy still exists to which surgical procedure is the best for graft survival and IOP control, as well as when is the best time of the surgery in patients with pre‐existing glaucoma, before, simultaneously or after, and if needed, graft surgery. Certainly a “try not to create glaucoma” strategy needs always to be followed by not producing additional iatrogenic risk factors with improved technique(s) and by respecting the tissue(s).

Preparation and outcome of swollen versus dextran deswollen grafts in descemet membrane endothelial keratoplasty (DMEK)

Aims/Purpose: To evaluate the influence of organ culture medium containing dextran on graft characteristics during preparation as well as the outcome of subsequent Descemet Membrane Endothelial Keratoplasty (DMEK).Methods: 31 corneoscleral rims of the Eye Bank of the University Hospital of Cologne with a donor age between 52 and 74 years were examined between 2018 and 2022 for their intraoperative preparation conditions and the outcome after performing 31 DMEKs. For this purpose, corneoscleral rims were randomized into two organ‐cultured groups, one immersed in culture medium with dextran (group A, n = 16) and the other in medium without dextran (group B, n = 15). The intraoperative graft preparation conditions were noted by using a standardized scoresheet, including splitting and stripping behaviour, central and peripheral attachment as well as graft fragility. The post‐operative outcome parameters were defined as Best Spectacle‐Corrected Visual Acuity (BSCVA), central and peripheral corneal thickness (CCT and PCT), endothelial cell count (ECC) and re‐bubbling rate.Results: In both groups, all 31 DM‐endothelium grafts were usable for DMEK. There was no significant difference in the intraoperative preparation conditions of swollen versus dextran deswollen DM‐endothelium grafts in respect to stripping (p = 0.722) and to Descemet membrane splitting behaviour (p = 0.013). The fragility of the grafts showed no significant difference (p = 0.433), as well as the peripheral scars indicating a pseudophakic donor (p = 1.000) and the tendency for central tearing (p = 0.484) during preparation. No significant difference in the outcome 12 months after DMEK in conditions of swollen versus dextran deswollen DM‐endothelium grafts regrading CCT (p = 0.189), re‐bubbling (p = 0.704), PCT (p = 0.063), could be observed. BSCVA was significantly better in group B 12 months after DMEK with p = 0.032 (group A 0.08 ± 0.38: group B 0.03 ± 0.13).Conclusions: This pilot study does not show relevant and significant differences between swollen versus dextran deswollen grafts in DMEK transplantation. Future prospective studies with higher patient numbers are needed. Our study suggests also non‐deswollen donors as suitable for DMEK surgery.

Performance outcomes from a DMEK peeling and preparation wet lab

ObjectiveTo evaluate the Descemet membrane endothelial keratoplasty (DMEK) preparation performance of trainee surgeons in an ex vivo human donor cornea DMEK wet lab simulation setting.MethodsHuman donor corneoscleral rims unsuitable for...

Long-Term Follow-Up of Descemet Stripping Only: Data Up to 7 Years Postoperatively.

The aim of this study was to report long-term follow-up of eyes undergoing Descemet stripping only (DSO). This was a retrospective study including 26 eyes of 20 patients undergoing DSO between December 2015 and November 2022. Eligibility criteria included peripheral endothelial cell count (ECC) >1000 cells/mm 2 and symptoms caused by central guttata. Patients underwent a central circular 4-mm descemetorhexis using a reverse Sinskey hook and a pair of descemetorhexis forceps using a peeling technique. Three parameters were measured before surgery and at last follow-up: best-corrected visual acuity (BCVA), central corneal thickness (CCT), and ECC measured centrally and at the periphery. The mean age was 73 ± 9 years [52-90 years]. The average follow-up period was 23.7 ± 24.8 months [3-84]. Twenty-two eyes responded to DSO with 20 female eyes (91%) and 2 male eyes (9%). The mean postoperative BCVA improved from 0.3 ± 0.17 logMAR to 0.09 ± 0.13 logMAR ( P value <0.05). The mean postoperative CCT decreased from 588 ± 41 μm to 546 ± 50 μm ( P -value <0.05). The mean postoperative central ECC was 780 ± 257 cells/mm 2 [484-1500]. Peripheral ECC decreased postoperatively (1837 ± 407 cells/mm 2 preoperatively to 864 ± 340 cells/mm 2 postoperatively, P value >0.05). Peripheral endothelial cell polymegathism was stable (average of 26.8% ± 6.8% preoperatively and 30.2% ± 14% postoperatively). Average peripheral endothelial cells polymorphism decreased postoperatively (63.1 ± 20.5% preoperatively to 33% ± 25% postoperatively, P value >0.05). Four eyes did not show improvement after DSO and underwent Descemet membrane endothelial keratoplasty surgery. There were 3 men (75%) and 1 women (25%). The preoperative trend was for nonresponders to have lower BCVA, higher CCT, more abnormal peripheral polymorphism, and polymegathism. The results of this study, with up to 7 years follow up, demonstrate the durability of DSO.

Five-year clinical outcomes of 107 consecutive DMEK surgeries.

The long-term clinical outcomes, postoperative complications, and graft survival of Descemet-membrane endothelial keratoplasty (DMEK) remain poorly understood. We retrospectively assessed these variables in all consecutive eyes that underwent DMEK for any indication in 2014-2018. The findings were compared to the long-term DMEK studies of five other groups (3-10-year follow-up). Patients underwent ophthalmological tests preoperatively, at 1, 3, 6, and 12 postoperative months, and then annually. Five-year graft survival was determined by Kaplan-Meier estimator. Change in best-corrected visual acuity (BCVA), endothelial-cell density (ECD), and central-corneal thickness (CCT) at each timepoint was determined. 107 eyes (80 patients; 72 years old; 67% female) underwent first-time DMEK for uncomplicated Fuchs endothelial corneal dystrophy (94% of eyes), pseudophakic bullous keratopathy (3%), and regraft after previous keratoplasty (3%). The most common complication was graft detachment requiring rebubbling (18%). Thirteen grafts (12%) failed at ≤15 months. Cumulative 5-year graft-survival probability was 88% (95% confidence intervals = 79-94%). BCVA improved from 0.6 logMAR preoperatively to 0.05 logMAR at 1 year (p<0.0001) and then remained stable. Donor ECD dropped by 47% at 6 postoperative months and then continued to decrease by 4.0%/year. Five-year endothelial-cell loss was 65% (from 2550 to 900 cells/mm2). CCT dropped from 618 to 551 μm at 5 years (p<0.0001). These findings are generally consistent with previous long-term DMEK studies. DMEK has low complication and high graft-survival rates and excellent clinical outcomes that persist up to 5 years post-surgery. DMEK seems to be a safe and effective treatment in the long term.