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

BACKGROUND: To 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. METHODS: This 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. RESULTS: Overall, 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). CONCLUSIONS: Rebubbling 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.

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

PURPOSE: 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. METHODS: 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 120 s in either a plastic or glass medium prior to delivery into the recipient's eye. The ECL was compared between the two groups 12-30 months post-operatively. RESULTS: ECL at 12-30 months 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. CONCLUSION: Staining of the DMEK graft in a plastic medium caused less ECL compared to the glass medium.

Graft failure rate and complications after Descemet membrane endothelial keratoplasty in eyes with pre-existing glaucoma.

PURPOSE: To evaluate the outcome of Descemet Membrane Endothelial Keratoplasty (DMEK) in eyes with pre-existing glaucoma. DESIGN: In this retrospective, observational case series we included data of 150 consecutive DMEKs in eyes with pre-existing glaucoma of 150 patients after excluding data of the second treated eye of each patient and of re-DMEKs during follow-up. Cumulative incidences of IOP elevation (IOP > 21 mmHg or ≥ 10 mmHg increase in IOP from preoperative value), post-DMEK glaucoma (need of an additional intervention due to worsening of the IOP), graft rejection, and graft failure rate were analyzed using Kaplan-Meier survival analysis. COX regression analysis was used to evaluate independent risk factors. RESULTS: The 36-month cumulative incidence of IOP elevation was 53.5% [95 CI 43.5-63.5%] and of post-DMEK glaucoma 36.3% [95 CI 26.3-46.3%]. Graft rejection occurred with a 36-month cumulative incidence of 9.2% [CI 95% 2.3-16.1]. None of the analyzed risk factors increased the risk for the development of graft rejection. The 36-month cumulative incidence of graft failure was 16.6% [CI 95% 8.4-24.8]. Independent risk factors for graft failure were the indication for DMEK "status after graft failure" (n = 16) compared to Fuchs' dystrophy (n = 74) (p = 0.045, HR 8.511 [CI 95% 1.054-68.756]) and pre-existing filtrating surgery via glaucoma drainage device (GDD) (n = 10) compared to no surgery/iridectomy (n = 109) (p = 0.014, HR 6.273 [CI 95% 1.456-27.031]). CONCLUSION: The risks of postoperative complications (IOP elevation, post-DMEK glaucoma, graft rejection, and graft failure) in patients with pre-existing glaucoma are high. In particular, pre-existing filtrating surgery via GDD implantation-but not trabeculectomy-and DMEK after graft failure increase the risk of graft failure.

The usefulness of lutein/trypan blue vital dye for the staining of corneal endothelium: a pilot study on DMEK pretreated tissues.

PURPOSE: The study aims to evaluate the usefulness of lutein/trypan blue vital dye for the staining of corneal tissues and endothelium-Descemet membrane (EDM) for Descemet membrane endothelial keratoplasty (DMEK). METHODS: Sixteen human corneal tissues (Eye Bank, Rome, Italy) were used. Corneal endothelium was tested at 25 s (T0), 1 min (T1), 2 min (T2), and 4 min (T4) from dye addition. Staining intensity and cell counting were compared. Stripped EDM was analyzed for selected apoptotic (AP, caspases, BCL2, BAX) and differentiation (VEGF-A, TGF-ß1RI, SMAD3/7, SMA) targets and changes in target expression. Protein extracts were analyzed through SDS-PAGE/IB. RESULTS: Although trypan blue staining produced the same color intensity of lutein/trypan blue dye in half the time, lutein/trypan blue reached a good and adequate color intensity at T4, which persisted even on excised and washed EDM grafts. Lutein/trypan blue-stained EDM showed a reduced number of blue-stained cells and AP immunoreactivity was significantly reduced in the same samples. An increased BCL2 transcript and a reduced BAX transcript were detected in lutein/trypan blue-stained EDM. No significant changes were observed for the main effector caspases (3/9) upon both treatments and the target genes representative of endothelial cell trans-differentiation (TGF-ß1RI, SMAD3/7, SMA). A trend in vascular endothelial growth factor (VEGF-A) regulation was observed in lutein/trypan blue-treated EDM grafts. CONCLUSION: Obtained results suggest that lutein/trypan blue dye deserves attention in the DMEK field and support the potential routine use of this dye as a valid alternative to trypan blue for all procedures devoted to the assessment of endothelial cell viability and visualization of EDM graft before DMEK grafting.

Predictive factors of graft detachment and rebubbling after descemet membrane endothelial keratoplasty.

PURPOSE: To identify risk and predictive factors associated with the need of rebubbling in the eye of patients who underwent a descemet membrane endothelial keratoplasty (DMEK). METHODS: The records of patients who underwent DMEK were retrospectively analyzed. Data regarding comorbidities, intraoperative characteristics, and postoperative treatments or complications were collected. The central corneal thickness (CCT) was measured by optical coherence tomography before and the day after DMEK. Univariate and multivariate analyses were performed. RESULTS: Of the 333 DMEK, rebubbling was performed in 119 cases (36%). Preoperative subepithelial fibrosis and a history of penetrating keratoplasty (PK) were associated with significantly more graft detachment [OR of 3.55 (2.02-6.32; P < 0.001) and 5.89 (2.00-21.86; P = 0.003), respectively]. A decreased CCT the day after surgery reduced by 5.7-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.93). Conversely, a 20% increase in the CCT the day after surgery increased by 4.5-fold the risk of rebubbling (sensitivity/specificity of 0.42/0.91). CONCLUSION: Variation of the CCT could be used as a predictive factor of rebubbling after DMEK. Patients with a 20% increase of CCT the day after surgery are at higher risk of graft detachment. Conversely, a reduced CCT the day after the surgery is associated with a reduced risk of rebubbling. Subepithelial fibrosis and history of PK were also identified as risk factors for rebubbling. Those predictive factors may help develop a customized approach for patients undergoing DMEK surgery.

Disparities in Visual Acuity Outcomes after Endothelial Keratoplasty: An Intelligent Research in Sight Registry Analysis.

PURPOSE: To assess risk factors for lack of vision improvement after endothelial keratoplasty (EK). DESIGN: Retrospective cohort study. PARTICIPANTS: Patients aged 18 years and older in the Intelligent Research in Sight (IRIS®) Registry who underwent EK surgery in the United States between 2013 and 2018. METHODS: Change in visual acuity (VA) relative to baseline were determined at 6 months and 1 year. A multivariable population-average marginal model estimated using generalized estimating equations adjusting for sociodemographic factors, baseline vision, surgical indication, ocular comorbidities, and postoperative complications was used to identify factors associated with worse VA outcomes. MAIN OUTCOME MEASURES: Visual acuity and lack of VA improvement at 1 year compared with preoperative status. RESULTS: A total of 30 600 EK procedures (N = 25 666 unique patients) were included in the analysis. Overall, VA improved from median logarithm of the minimum angle of resolution (logMAR) 0.54 (Snellen 20/69) (interquartile range [IQR] ± 0.70) preoperatively to median logMAR 0.40 (20/50) (IQR ± 0.36) at 6 months and median logMAR 0.30 (20/40) (IQR ± 0.36) at 1 year postoperatively. A total of 30.3% of the overall cohort, 29.8% of Fuchs' endothelial corneal dystrophy (FECD) subgroup, and 27.4% of the bullous keratopathy (BK) subgroup did not show visual improvement at 1 year postoperatively. In the FECD subgroup, older age (risk ratio [RR], 1.05 per 5-year increase, 95% confidence interval [CI], 1.03-1.07) and female sex (RR, 1.10, 95% CI, 1.04-1.16) were associated with VA worse than or equal to baseline at 1 year postoperatively. In both FECD and BK subgroups, eyes with higher baseline logMAR VA (per 0.1 unit increase in logMAR) were more likely to have visual improvement postoperatively (FECD: RR, 0.82, 95% CI, 0.81-0.84; BK: RR, 0.91, 95% CI, 0.91-0.92), whereas postoperative rebubbling (FECD: RR, 1.10, 95% CI, 1.02-1.19; BK: RR, 1.31, 95% CI, 1.17-1.48) and repeat keratoplasties (FECD: RR, 1.41, 95% CI, 1.32-1.52; BK: RR, 1.42, 95% CI, 1.28-1.57) were associated with higher risk of no VA improvement. CONCLUSIONS: In this large national cohort, postoperative rebubblings and repeat keratoplasties were identified as independent factors associated with worse VA outcomes after EK for both FECD and BK subgroups. Older age and female gender were associated with worse VA outcomes after EK in the FECD subgroup.

Pediatric endothelial keratoplasty: a systematic review and individual participant data meta-analysis.

BACKGROUND: Recently, endothelial keratoplasty (EK) has been increasingly considered the first intervention in pediatrics with isolated corneal endothelial dysfunction. This systematic review aims to investigate the current evidence about the advantages, disadvantages, technical challenges, and clinical outcomes of EK in the pediatric group. METHOD: All the English literature relevant to pediatric EK was searched in PubMed, Embase, Scopus, and Cochrane databases with appropriate keywords. Relevant data were pooled to conduct an individual participant data meta-analysis. RESULTS: Of 1646 articles found initially, 35 articles were finally eligible to be included in our study. A total of 154 eyes of 107 patients underwent Descemet's stripping automated endothelial keratoplasty (DSAEK). Congenital hereditary endothelial dystrophy (CHED) was the most reported indication for pediatric DSAEK (108 eyes). Descemet's membrane endothelial keratoplasty (DMEK) was performed in 2 eyes of 2 cases, one with PPCD and another one in a patient with Kearns-Sayre syndrome. Owing to some specific anatomical and physiological pediatric characteristics, some modifications in a standard procedure were suggested. The average follow-up period was 23.80 ± 20.18 months (3 months to 8.5 years). Seventy-six eyes who had a mean best-corrected visual acuity (BCVA) of 1.36 ± 0.70 (0.49 to 3) logMAR preoperatively found mean BCVA of 0.51 ± 0.33 (0.04 to 2) logMAR postoperatively. Graft dislocation was the most reported complication (26 eyes). The rate of other complications was low. Endothelial cell loss was reported from 8.3 to 63.7% after pediatric EK with follow-up duration from 3 months to 8.3 years. CONCLUSION: EK procedures, despite some technical challenges, are feasible surgical techniques with acceptable visual and anatomical outcomes in the management of pediatrics with corneal endothelial dysfunction and minimal stromal involvement.

The Cologne-Mecklenburg-Vorpommern DMEK Donor Study (COMEDOS) - design and review of the influence of donor characteristics on Descemet membrane endothelial keratoplasty (DMEK) outcome.

BACKGROUND: Posterior lamellar keratoplasty and especially Descemet membrane endothelial keratoplasty (DMEK) are gaining interest worldwide. Little is known about the influence of donor factors on DMEK outcome. Here we provide an overview of the existing peer-reviewed literature on this topic and present the design of the upcoming cooperation study COMEDOS (Cologne-Mecklenburg-Vorpommern DMEK Donor Study). METHODS: A literature search of PubMed and MEDLINE was conducted to retrieve articles published between September 2013 and May 2021. Seventeen peer-reviewed articles were selected. Design and concept of the prospective COMEDOS are outlined. RESULTS: Main interest parameters were the donor diabetes mellitus status, age, and lens status. There is a large heterogeneity regarding the sample size, study design, and investigated parameters. There seems to be a consensus that younger donors are associated with tighter rolls, a more difficult preparation, and unfolding setting. Diabetic donors seem to increase the risk of tissue tearing due to adherences and result more frequently in preparation failure. The COMEDOS aims not only to analyze the diabetes status of the donor, but also to correlate all donor systemic comorbidities and their ophthalmologic history to the DMEK clinical outcome. Furthermore, a correlation of Descemet membrane lamella preparation and surgery outcome is planned. CONCLUSION: Currently, there is a lack of knowledge regarding the effect and impact of donor tissue characteristics on DMEK outcome and complications. An in-depth investigation is planned by the upcoming COMEDOS to close this knowledge gap.

Impact of DMEK on visual quality in patients with Fuchs' endothelial dystrophy.

PURPOSE: To investigate short-term (3 months follow-up) changes in visual quality following Descemet membrane endothelial keratoplasty (DMEK) for Fuchs endothelial dystrophy (FED). METHODS: In this prospective institutional case series, 51 patients that underwent DMEK for FED were included. Assessment included the Quality of Vision (QoV) questionnaire preoperatively, at 1 month, and 3 months after surgery. Secondary outcome measures were anterior segment parameters acquired by Scheimpflug imaging, corrected distance visual acuity (CDVA), and endothelial cell density (ECD). RESULTS: Glare, hazy vision, blurred vision, and daily fluctuation in vision were the symptoms mostly reported preoperatively. All symptoms demonstrated a significant reduction of item scores for severity, frequency, and bothersome in the course after DMEK (P < 0.01). Glare and fluctuation in vision remained to some extent during the follow-up period (median score = 1). Preoperatively, corneal densitometry correlated moderately to weakly with severity of hazy vision (rs = 0.39; P = 0.03) and frequency (rs = 0.26; P = 0.02) as well as severity (rs = 0.27; P = 0.03) of blurry vision. CDVA and central corneal thickness (CCT) did not correlate with visual complains. CONCLUSIONS: Following DMEK for FED, patient-reported visual symptoms assessed by the QoV questionnaire represent a useful tool providing valuable information on the impact of DMEK on visual quality that cannot be directly estimated by morphological parameters and visual acuity only.

Retinometer predicts visual outcome in Descemet membrane endothelial keratoplasty.

PURPOSE: To analyze the preoperative predictive value of retinometer visual acuity (VA) in eyes following Descemet membrane endothelial keratoplasty (DMEK). METHODS: Patients undergoing DMEK between August 2011 and July 2020 were included. Preoperative interference visual acuity was assessed using Heine Lambda 100 Retinometer. Depending on the presence or absence of concomitant ocular disease, the Retinometer was evaluated for its ability to preoperatively predict best-corrected visual acuity (BCVA) six months after surgery using correlation, simple and multiple linear regression, contingency analyses, and receiver operating characteristic (ROC) analysis. Preoperative corneal backscatter was correlated with Retinometer prediction accuracy. RESULTS: A total of 198 eyes were included in the analysis. There was a significant correlation between Retinometer VA and postoperative BCVA (r = 0.647, P < 0.001). Regardless of the presence or absence of concomitant ocular disease and the surgery procedure (DMEK & triple DMEK), Retinometer VA was the most significant predictor of postoperative BCVA (P < 0.001). ROC analysis revealed reliable diagnostic performance of the Retinometer (AUC = 0.829, P < 0.001). A Retinometer VA ≥ 0.5 accurately predicted a postoperative BCVA ≥ 0.5 in 91% of cases. No association was found between corneal backscatter and prediction accuracy (P = 0.566). CONCLUSIONS: Retinometer VA can be used for preoperative prediction of postoperative BCVA in DMEK and triple DMEK patients, independent of increased backscatter values and the presence or absence of concomitant ocular disease. By using this simple but effective tool, indication for DMEK can be facilitated and postoperative outcomes can be realistically predicted preoperatively.

Five-year follow-up of corneal morphology and corneal refractive power changes after uneventful DMEK.

PURPOSE: To investigate changes of corneal thickness spatial profile (CTSP), corneal volume (CV) distribution, and total corneal refractive power (TCRP) over a course of 60 months after uneventful Descemet membrane endothelial keratoplasty (DMEK). METHODS: In our prospective, comparative study, sixty DMEK cases without intraoperative and postoperative complications and with complete 60-month follow-up were included (group 1). CTSP at corneal apex (CCT) and at 2 mm, 4 mm, 6 mm, and 8 mm rings, CV in 3 mm, 5 mm, 7 mm, and 10 mm zones, and TCRF in 2 mm, 4 mm 6 mm, and 8 mm zones were evaluated preoperatively and at 3, 6, 12, 24, and 60 months postoperatively. The 60-month results were compared to an age-matched group of uncomplicated pseudophakic eyes (group 2; n = 20). RESULTS: The CCT and CTSP at 2, 4, and 6 mm increased significantly at 60 months compared to 3-month outcomes (P < 0.001). Similarly, CV increased significantly in 3 mm, 5 mm, and 7 mm zones at 60 months compared to 3 months outcomes (P < 0.001). The TCRP showed in all zones a significant decrease at 3 months (P < 0.001) followed by a continuous and significant increase at 60 months (P < 0.001). The 60-month CCT and CTSP at 2 mm were similar to group 2 (P ≥ 0.094). CONCLUSION: Sixty months after uneventful DMEK, CT within the central 2 mm zone and CV at 3 mm zone were similar to uncomplicated pseudophakic eyes. A continuous and statistically significant increase of TCRP was observed in all measured zones after the 3-month examination.

Optimizing intraocular lens power calculation using adjusted conventional keratometry for cataract surgery combined with Descemet membrane endothelial keratoplasty.

PURPOSE: To evaluate the utility of intraocular lens (IOL) power calculation using adjusted conventional keratometry (K) according to postoperative posterior to preoperative anterior corneal curvature radii (PPPA) ratio for eyes with Fuch's dystrophy undergoing cataract surgery combined with Descemet membrane endothelial keratoplasty (triple DMEK). METHODS: A fictitious refractive index (FRI) was determined (Pentacam HR®) based on the PPPA ratio in 50 eyes undergoing triple DMEK. Adjusted corneal power was calculated in every eye using adjusted K values: K values determined by the IOLMaster were converted to adjusted anterior corneal radius using the mean FRI. Posterior corneal radius was calculated using the mean PPPA ratio. Adjusted corneal power was determined based on the calculated corneal radii and thick lens formula. Refractive errors calculated using the Haigis, SRK/T, and HofferQ formulae based on the adjusted corneal power were compared with those based on conventional K measurements. RESULTS: Calculated PPPA ratio and FRI were 0.801 and 1.3271. Mean prediction error based on conventional K was in the hyperopic direction (Haigis: 0.84D; SRK/T: 0.74D; HofferQ: 0.74D) and significantly higher (P < 0.001) than that based on adjusted corneal power (0.18D, 0.22D, and 15D, respectively). When calculated according to adjusted corneal power, the percentage of eyes with a hyperopic shift > 0.5D fell significantly from 64 to 30% (Haigis), 62 to 36% (SRK/T), and 58 to 26% (HofferQ), respectively. CONCLUSION: IOL power calculation based on adjusted corneal power can be used to reduce the risk of a hyperopic shift after triple DMEK and provides a more accurate refractive outcome than IOL power calculation using conventional K.

Graft survival of Descemet membrane endothelial keratoplasty (DMEK) in corneal endothelial decompensation after glaucoma surgery.

PURPOSE: This study aims to assess the results, rebubbling rate, and graft survival after Descemet membrane endothelial keratoplasty (DMEK) with regard to the number and type of previous glaucoma surgeries. METHODS: This is a clinical retrospective review of 1845 consecutive DMEK surgeries between 07/2011 and 08/2017 at the Department of Ophthalmology, University of Cologne. Sixty-six eyes were included: group 1 (eyes with previous glaucoma drainage devices (GDD); n = 27) and group 2 (eyes with previous trabeculectomy (TE); n = 39). Endothelial cell loss (ECL), central corneal thickness, graft failure, rebubbling rate, and best spectacle-corrected visual acuity (BSCVA) up to 3 years after DMEK were compared between subgroups of patients with different numbers of and the two most common types of glaucoma surgeries either GDD or TE or both. RESULTS: Re-DMEK rate due to secondary graft failure was 55.6% (15/27) in group 1 and 35.9% in group 2. The mean graft survival time in group 1 was 25 ± 11 months and 31.3 ± 8.6 months in group 2 (p = 0.009). ECL in surviving grafts in group 1 was 35% (n = 13) at 6 months, 36% at 12 months (n = 8), and 27% (n = 4) at 2 years postoperatively. In group 2, ECL in surviving grafts was 41% (n = 10) at 6 months, 36% (n = 9) at 12 months, and 38% (n = 8) at 2 years postoperatively. Rebubbling rate in group 1 was 18.5% (5/27) and 35.9% (14/39) in group 2 (p = 0.079). CONCLUSION: Eyes with previous GDD had no higher risk for an increased rebubbling rate but a higher risk for a re-DMEK due to secondary graft failure with a mean transplant survival time of about 2 years. Compared to eyes with preexisting glaucoma drainage device, eyes after trabeculectomy had less secondary graft failures and a longer mean graft survival rate.

DMEK after penetrating keratoplasty: cohort with DMEK grafts and descemetorhexis larger than full-thickness graft.

PURPOSE: The study aims to evaluate visual outcome, central corneal thickness, and rebubbling rate in a cohort with oversized DMEK grafts after failed penetrating keratoplasty (PK). The unique feature of the study is a descemetorhexis diameter larger than the full-thickness graft, i.e., peripheral to the PK interface. METHODS: A monocentric, retrospective evaluation of all patients with endothelial graft failure after PK treated with an oversized DMEK graft and descemetorhexis outside of the PK interface (i.e., in host tissue) between January 2015 and July 2019 at the Department of Ophthalmology at the University of Düsseldorf (Germany) was performed. RESULTS: Eleven eyes of 10 patients were identified. Mean age was 69 years. On average (arithmetic mean ± standard deviation), 1.7 ± 1.0 previous PKs have been performed per eye in this cohort. The mean time between last PK and DMEK was 10.1 ± 7.3 years (range 2 to 23 years). In all cases, the graft diameter exceeded the diameter of the previous PK and descemetorhexis was performed in host tissue, that is, peripheral to the graft-host interface. Rebubbling was performed in 18.2% of the patients (n = 2 eyes) because of central graft detachment. Mean central corneal thickness showed a statistically significant improvement at 5.3 ± 3.5 months after surgery from 688.23 ± 151.01 to 527.75 ± 88 µm (p = 0.002). Visual acuity increased significantly by 5 lines from 1.24 ± 0.5 logMAR (range from 0.5 to 2) to 0.73 ± 0.76 logMAR (range from 0.1 to 2) within 3 months (p = 0.006). Excluding patients without visual potential and transplant failure, visual acuity improved significantly by 8 lines (p < 0.001), and stayed stable until the last follow-up at 15.1 ± 11.4 months (range 6 to 39 months, p < 0.001, n = 8) after surgery. CONCLUSION: DMEK can be successfully used to treat endothelial cell failure after PK, and can provide good postoperative results with regards to visual acuity. This study shows that stripping of Descemet's membrane (DM) peripheral to the PK interface is surgically feasible. Overlapping, larger DMEK grafts with more endothelial cells can be used without increasing rebubbling rates and may potentially improve long-term graft survival.

Ability of routinely collected clinical factors to predict good visual results after primary Descemet membrane endothelial keratoplasty: a cohort study.

BACKGROUND: A comprehensive analysis of routinely collected pre/perioperative demographic/clinical factors that could predict final visual acuity after primary Descemet membrane endothelial keratoplasty (DMEK) has not been conducted previously. METHODS: A retrospective monocenter cohort study was performed with consecutive patients with Fuchs endothelial corneal dystrophy (FECD) who underwent DMEK or triple-DMEK (DMEK combined with cataract surgery) in 2016-2020 in a French tertiary-care hospital. DMEK-only patients were pseudophakic. Patients were followed for 12 months. Surgery was considered successful when 12-month best-corrected visual acuity (BCVA) was ≤0.1 logMAR (≥0.8). Exploratory multivariate analysis was conducted with the following routinely collected variables to determine their ability to predict 12-month BCVA: patient age and sex; graft donor age; triple DMEK; preoperative values of BCVA, endothelial cell density (ECD), central corneal thickness (CCT), and mean anterior keratometry; and rebubbling. RESULTS: Of 100 eyes (100 patients; mean age, 72 years; 61% female), 81 achieved a 12-month BCVA of ≤0.1 logMAR. Logistic regression analysis showed that older age was a significant prognosticator for 12-month BCVA > 0.1 logMAR (Odds Ratio = 0.914, 95% confidence intervals = 0.846-0.987; p = 0.02). CONCLUSIONS: An older age associated with worse visual acuity outcomes after DMEK. This was confirmed by our analysis of the literature and supports the notion that DMEK should be conducted without delay once symptoms appear. Patient sex, donor age, triple-DMEK, and anterior keratometry also did not predict final BCVA in the literature. Preoperative CCT, ECD, and BCVA, and rebubbling occasionally appear in the literature as BCVA predictors, possibly reflecting an underlying ECD-BCVA axis.

Comparison of clinical outcomes after precut DMEK with or without dextran-containing medium compared to standard DMEK: a prospective pilot study.

PURPOSE: To investigate the clinical outcome and complication rate of precut Descemet membrane endothelial keratoplasty (DMEK) in two different culture conditions, dextran-containing and dextran-free medium, and compare the results with the current standard DMEK procedure. METHODS: A prospective study of 32 eyes suffering from Fuchs endothelial dystrophy were scheduled for DMEK with a follow-up of one year. The eyes were divided into four subgroups. Group + D (n = 7) received a precut DMEK stored in dextran-containing transport medium, and Group - D (n = 9) received a precut DMEK without dextran-containing medium. The respective fellow eyes received a standard DMEK (S) (preparation directly prior to surgery) stored in dextran-containing medium (S-D + ; n = 7) or without (S-D-; n = 9). RESULTS: Clinical outcome (visual acuity, endothelial cell count, central corneal thickness) and rebubbling rate were comparable for all four groups. None of the patients had a graft failure. CONCLUSION: The preliminary data of the pilot study show that precut liquid-bubble DMEK leads to comparable clinical results regardless of dextran-containing or dextran-free organ culture medium and is further comparable to the standard DMEK procedure.

Clinical results after single asymmetrical shark fin for graft orientation in DMEK.

PURPOSE: Evaluating the effect of a single peripheral triangular mark to ensure the correct anterior-posterior graft orientation in DMEK. METHODS: Retrospective study of patients scheduled for DMEK due to Fuchs endothelial dystrophy and divided into 2 study groups: Group -M (n = 184) had no mark of the EDM (Endothelial Descemet membrane) and group + M (n = 193) had a triangular peripheral mark. Follow-up time was 1 year after surgery. RESULTS: The postoperative graft turning and Re-DMEK rate could be significantly reduced by the use of a peripheral mark (p = 0.002, p = 0.001, respectively). Re-DMEK due to primary graft failure was significantly associated with prior graft turning (p < 0.001). Both groups showed comparable values for visual acuity, central corneal thickness and endothelial cell count after a follow-up of 1 year. CONCLUSION: Single peripheral triangular marking is a simple and cost-saving addition to EDM preparation to ensure the correct orientation of the graft intraoperatively and could lead to a significant reduction in graft turning and re-DMEK rate in this study.

Descemet membrane endothelial keratoplasty: analysis of clinical outcomes of patients with 8-10 years follow-up.

PURPOSE: This study aimed to evaluate the clinical outcomes up to 10 years after Descemet membrane endothelial keratoplasty (DMEK). METHODS: In this retrospective, consecutive, single-center case series the medical files of eyes which have received DMEK between 2009 and 2012 for the treatment of endothelial dysfunction was evaluated regarding follow-up time and clinical outcomes. Annual examinations of best-corrected visual acuity (BCVA), endothelial cell density (ECD), central corneal thickness (CCT) of 66 eyes which fulfilled the criterion of a minimum of 8 years follow-up were analyzed. RESULTS: BCVA improved from 0.55 ± 0.37 logMAR (n = 54) to 0.15 ± 0.11 (n = 47) in eyes without ocular comorbidities one year after DMEK (p < 0.001), and remained stable up to 10 years after DMEK. Mean ECD decreased to 744 ± 207 cells/mm2 (n = 39) after 9 years, and to 729 ± 167 cells/mm2 (n = 21) after 10 years, respectively. CCT decreased from 650 ± 67 µm before DMEK to 525 ± 40 µm (n = 56) after 1 year, increasing slowly to 563 ± 40 µm (n = 39) after 9 years, and to 570 ± 42 µm (n = 21) after 10 years, respectively. Graft failure occurred in 4 of 66 eyes after year 8. These 4 eyes required repeat DMEK after 101-127 months. CONCLUSION: This study shows the long-term outcomes in a small subset of DMEK grafts. Visual acuity remained stable in spite of slowly increasing corneal thickness and diminishing endothelial cell density during the 10-year period after DMEK.

Surgeons preferences in descemet membrane endothelial keratoplasty (DMEK).

AIM: To explore the attitudes, preferences, and barriers of DMEK among corneal specialists in Saudi Arabia. METHOD: An anonymous survey was sent through an online platform to members of the Saudi Ophthalmological Society. The survey was designed to capture data covering: demographic data, practice patterns of keratoplasty techniques, DMEK technique preferences, barriers, and facilitators to performing DMEK. RESULTS: Thirty-five (33% response rate) surgeons participated in the questionnaire. Sixty-eight percent were in practice for less than or equal to 10 years. Thirteen surgeons were performing DMEK. Participating in any training capacity was observed among surgeons who performed DMEK (92%). The main selection criteria for this procedure were patients with normal anterior chamber anatomy (77%). The main barrier against DMEK adoption among surgeons who do not perform the procedure was the lack of experience (91%). Strategies to help begin performing DMEK were eye banks support (prepared grafts, backup tissue for inadvertent loss), access to wet-lab training courses, and higher surgical volume. CONCLUSION: DMEK is not highly performed among corneal specialists in Saudi Arabia; however, there is evident interest in adopting this technique. Strategies toward filling the gap of lacking experience would facilitate the adoption of the procedure. Eye banks play a crucial role by providing prepared tissues, which would lessen part of the technical difficulty.

[Morphological characteristics of Descemet's membrane removed during endothelial keratoplasty (case study)]. / Morfologicheskie osobennosti udalennoi pri endotelial'noi keratoplastike destsemetovoi membrany (klinicheskie nablyudeniya).

The two most used modifications of endothelial keratoplasty (EK) are Descemet's membrane endothelial keratoplasty (DMEK) and Descemet's stripping automated endothelial keratoplasty (DSAEK). The leading complication of EK surgeries is graft detachment in the early postoperative period. This article reports on two cases of endothelial graft adhesion depending on morphological characteristics of the Descemet's membrane (DM) removed during EK. In the first case, complete graft attachment to the recipient's posterior stroma was observed after DMEK. Morphological analysis of the DM showed clean stromal surface. In the second case there was a false chamber between the endothelial transplant and the posterior stroma of the patient. OCT scans revealed separate stromal fibers protruding into the false chamber; morphological analysis of the removed DM showed stromal fragments fixed to the anterior surface of the DM. The revealed changes indicate damage to the posterior stroma the suffered received during descemetorhexis, which may be the cause for incomplete graft attachment. Complete attachment after repeated EK (DSAEK) in this case was due to a thin stromal layer on the graft that provided high degree of adhesion to the posterior corneal surface. DSAEK can be indicated as a repeated EK surgery in cases of persistent endothelial graft non-attachment after DMEK.