Descemet Membrane Endothelial Keratoplasty Surgery Research Articles

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>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.

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.

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/mm2 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/mm2 [484-1500]. Peripheral ECC decreased postoperatively (1837 ± 407 cells/mm2 preoperatively to 864 ± 340 cells/mm2 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.

Scheimpflug Corneal Densitometry Patterns at the Graft-Host Interface in DMEK and DSAEK: A 12-Month Longitudinal Comparative Study.

To compare corneal densitometry (CD) patterns at the graft-host interface between Descemet Membrane Endothelial Keratoplasty (DMEK) and Descemet Stripping Automated Endothelial Keratoplasty (DSAEK). Corneal densitometry is a quantitative assessment that objectively evaluates corneal clarity and optical quality by measuring the light backscatter from the cornea. Fifty-one eyes that received DMEK or DSAEK surgery for corneal endothelium dysfunction were evaluated. The primary endpoint included CD patterns at the graft-host interface, which were assessed by the Pentacam HR device at the center point of the corneal horizontal meridian (CDcentral), and at six points on the central circumference of the cornea (with a total diameter of 4 mm) (CDI,II,III,IV,V,VI). Secondary endpoints included the best-corrected distance visual acuity (BCDVA), central corneal thickness (CCT), and graft thickness (GT). All of the evaluations were performed at follow-up appointments one, three, six and twelve months after the procedure. DMEK showed a significant overall CD reduction of -7.9 ± 8.5 grayscale unit (GSU) compared to DSAEK (p < 0.001). In addition, the DMEK group showed significantly lower CDCentral,I,II,III,IV,V,VI values at follow-up appointments one, three, six and twelve months after the procedure compared to the DSAEK group (p < 0.001). BCDVA, CCT and GT were in favor of the DMEK group with a mean value of 0.39 ± 0.35 LogMar, 552.2 ± 71.1 µm and 11.03 ± 1.4 µm, respectively (p < 0.001). CD patterns at the graft-host interface seem to be different depending on the endothelial keratoplasty procedure. This provides specific insight into CD changes in this critical region of surgery, which may provide a better understanding of the postoperative evolution of these patients.

Comparison of efficacy of three gases for anterior chamber tamponade in Descemet's membrane endothelial keratoplasty

To compare the efficacy of three different gases for intraocular tamponade: 100% air, 10% perfluoropropane (C3F8), and 10% sulfur hexafluoride (SF6), in Descemet's membrane endothelial keratoplasty (DMEK). The medical records of 138 patients who underwent DMEK were reviewed retrospectively, with the primary outcome being the rebubbling rate in the first week following surgery. Other clinical outcomes, such as best-corrected visual acuity (BCVA), central corneal thickness (CCT), incidence of rebubbling after the first week, endothelial cell density (ECD), graft detachment, graft failure, pupillary block, and intraocular pressure (IOP) changes were also analyzed. Of the 138 patients, 57 were in group 1 (treated with air), 44 in group 2 (treated with 10% C3F8), and 37 in group 3 (treated with 10% SF6). Group 3 showed significantly lower rates of graft detachment and rebubbling compared to groups 1 and 2 (P<0.001). However, there was no significant difference in postoperative BCVA among the groups. At one year, the mean endothelial cell loss was 32% in group 1, 30% in group 2, and 33% in group 3 (P=0.715). One patient in group 1 experienced pupillary block and increased IOP, while there were no such occurrences in the other groups. There was no difference between the groups in terms of graft failure. The use of 10% SF6 in DMEK surgery may be a good option due to its efficacy in preventing graft detachment, low rebubbling rate, and potential for minimizing complications.

Challenges of DMEK Technique with Young Corneal Donors' Grafts: Surgical Keys for Success-A Pilot Study.

To report on the surgical maneuvers recommended for a successful unfolding of very young donors in order to accomplish an uneventful Descemet Membrane Endothelial Keratoplasty (DMEK) surgery. Five patients (three females and two males, mean age 71.2 ± 6.7 years) with Fuchs endothelial cell dystrophy who underwent DMEK with very young donors (between 20 and 30 years old) were included. The following demographic data were assessed: donor's age, donor's endothelial cell density (ECD), preservation time, recipient's age and sex and unfolding surgical time. Best-corrected visual acuity (BCVA; decimal system), ECD and corneal central thickness (CCT) were assessed preoperatively and at 6-month follow-up. Donors' mean age was 23.6 ± 3.6 years (range 21 to 30) and the mean ECD was 2748.6 ± 162.6 cells/mm2. All of them underwent an uneventful DMEK as a single procedure performed by one experienced surgeon (MAG) with a mean unfolding time of 7.2 ± 4.9 min (range 4 to 15). The essential steps, including patient preparation as well as DMEK graft implantation, orientation, unrolling and centering are detailed. At 6 months, BCVA was 0.6 ± 0.2, ECD was 1945.0 ± 455.5 cells/mm2 and CCT was 497.0 ± 19.7 microns. We hereby present the keys to overcome tightly scrolled grafts of very young donors, which prove perfectly suitable for DMEK surgery. The graft shape tends towards a double-roll and specific maneuvers are strongly recommended.

Persistent Localized Descemet Membrane Endothelial Keratoplasty Detachments Secondary to Corneal Ink Stain Marks.

The aim of this study was to describe 2 cases of persistent endothelial graft detachments secondary to corneal gentian violet ink stain marks. This study included a case review of hospital records of 2 eyes with localized Descemet's membrane detachments after Descemet membrane endothelial keratoplasty (DMEK) surgery. Two patients underwent consecutive uncomplicated DMEK surgery for Fuchs endothelial dystrophy with identical techniques. The grafts were marked with an ink marker through a stromal window to ensure correct orientation during donor graft preparation. Both patients had localized detachments around the ink mark on day 1, week 1, and up to 1 month at postoperative review. The persistent detachment was believed to be due to the gentian violet marker used which had a higher concentration of isopropyl alcohol solvent than the standard marking pen routinely used. Ink markers with higher concentrations of isopropyl solvent may result in higher DMEK detachment rates and caution is advised when using these markers.

Optical quality of the cornea after Descemet membrane endothelial keratoplasty surgery: early results from Türkiye.

Descemet membrane endothelial keratoplasty (DMEK) is increasingly favored in the treatment of endothelial dysfunction due to its benefits, which include swift visual rehabilitation and recovery, a relatively low rejection rate, and superior refractive stability. In this study, we examined alterations in corneal clarity among patients who underwent DMEK and correlated these densitometry findings with other optical parameters of corneal topography. The study incorporated 35 eyes from 35 patients who had previously undergone DMEK surgery for pseudophakic bullous keratopathy at Ankara Bilkent City Hospital. The results from these patients were compared with those from a healthy control group. The preoperative and postoperative optical parameters of the patients were assessed using Pentacam Scheimpflug topography (Oculus). We observed significant decreases in corneal densitometry in the 0-2 mm and 2-6 mm zones of the anterior, posterior, central, and total layers at the sixth month postoperatively compared to the preoperative period (P<0.05). The corneal densitometry values at postoperative month 6 were elevated in all layers and zones relative to the healthy group (P<0.05). The root mean square of higher-order aberrations in postoperative period was elevated significantly (P<0.001). Six months after operation, the optical quality of the cornea following DMEK surgery did not achieve the level of a healthy cornea.

Descemet Membrane Endothelial Keratoplasty and Descemet Stripping Only Using a 3D Visualization System.

(1) Purpose: The aim was to analyze the outcomes of Descemet's membrane endothelial keratoplasty (DMEK) and Descemet stripping only (DSO) surgeries using a glasses-assisted NGENUITY® 3D visualization system (Alcon Laboratories, Fort Worth, TX, USA). (2) Methods: Five consecutive cases of DMEK surgery and four consecutive cases of DSO were performed using the NGENUITY® system in this prospective study carried out at the Arruzafa Hospital, Córdoba, Spain. Only one eye from each patient received surgery. Best corrected distance visual acuity (CDVA) using EDTRS charts, central corneal thickness using the Casia II optical coherence tomograph (Tomey Co., Nagoya, Japan), and endothelial cell count using the Tomey EM-4000 (Tomey Co., Nagoya, Japan) for DMEK cases or the Nidek CEM-530 (Nidek Co., Ltd., Gamagori, Japan) specular microscopes for DSO cases were recorded preoperatively and at 1 and 3 months postsurgery. (3) Results: DMEK cases included one male and four female subjects, with a mean age of 73.6 ± 9.5 years. Average improvement in CDVA 3 months after surgery was 0.46 ± 0.16 decimal. Average change in cell count between 1 and 3 months postsurgery was 360.75 ± 289.38 cells/mm2. DSO cases included four female subjects, with a mean age of 64.2 ± 9.7 years. The average improvement in CDVA 3 months after surgery was 0.09 ± 0.17 decimal. All cases also had phacoemulsification carried out. He average change in cell count between 1 and 3 months after surgery was 460 ± 515.69 cells/mm2. There were no associated complications during surgery or the follow-up period in any of the cases. (4) Conclusions: In addition to the known benefits of the use of a 3D visualization system during surgery, the present study shows that the system can be successfully used in both DMEK and DSO procedures with a very short learning curve for the surgeon.