Intraoperative optical coherence tomography guided corneal sweeping for removal of remnant Interface fluid during ultra-thin Descemet stripping automated endothelial keratoplasty.

BACKGROUND: Remnant interface fluid following Descemet stripping automated endothelial keratoplasty (DSAEK) is associated with postoperative detachments. The aim of this study was to assess outcomes of intraoperative optical coherence tomography (iOCT) guided meticulous peripheral corneal sweeping for removal of interface fluid during ultra-thin (UT) DSAEK. METHODS: This retrospective study included all eyes underwent iOCT guided UT-DSAEK from October 2016 to February 2018 at the Hanusch Hospital, Vienna, Austria. Peripheral meticulous corneal sweeping was performed to remove excess fluid. Central graft thickness (CGT) was measured prior to surgery, after graft bubbling and after corneal sweeping. Remnant interface fluid rates were compared between eyes that underwent rebubbling and those that did not. RESULTS: Overall, 28 eyes of 28 patients with a mean age of 73.9 ± 10.0 years were included. An iOCT guided meticulous peripheral sweeping was performed in 89.3% (n = 25) of the cases. Following 84% (n = 21) of the peripheral sweeping performed, remnant fluid was no longer identified. Following peripheral sweeping the interface fluid height was reduced from 17.31 ± 15.96 µm to 3.46 ± 9.52 µm (p < 0.001) and CGT was reduced by 7% (p < 0.001). Rebubbling was performed in 17.9% (n = 5) of the cases. The rebubbling group had a greater proportion of patients that had remnant fluid identified with iOCT at the end of surgery despite meticulous peripheral sweeping (60.0% versus 4.4%, p = 0.01). CONCLUSION: The iOCT identified subclinical remnant fluid in nearly 90% of UT-DSAEK cases. An iOCT guided peripheral corneal sweeping led to resolution of interface fluid in a majority of cases. Eyes with persistent remnant fluid despite peripheral corneal sweeping are more likely to require subsequent rebubbling.

Single versus double pass technique for preparation of ultrathin Descemet's stripping automated endothelial keratoplasty tissues from donated whole eyes.

This study was conducted to analyze the preoperative thickness profile and endothelial rating of ultrathin Descemet's stripping automated endothelial keratoplasty (UT-DSAEK) tissues prepared with a single versus double microkeratome pass from donated whole eyes and corresponding eye bank postoperative results. Microkeratome-assisted UT-DSAEK tissues were prepared from freshly donated whole eyes with single-pass (SP) and double-pass (DP) technique in the Central Eye Bank of Iran. Preoperative thickness profiles and endothelial cell densities of UT-DSAEK tissues were obtained from optical coherence tomography and specular microscopy, respectively, and compared between groups. Corneal perforation rates during the eye bank preparation and postoperative reports of transplanted UT-DSAEK tissues were also compared. Over a 15-month period, 342 UT-DSAEK tissues were prepared: 248 via SP and 94 with DP technique. Mean donor corneal central thickness was 610 ± 58 µm with SP and 790 ± 100 µm with DP technique. Mean central thickness of UT-DSAEK tissues was not statistically different between the groups (84.8 ± 11.0 µm with SP and 85.1 ± 10.5 µm with DP technique, P = 0.857). Mean increase of UT-DSAEK thickness from central to pericentral and peripheral cornea was not significantly different with both techniques. Mean differences between thicknesses of 2 pericentral locations and between those of 2 peripheral locations were not statistically different in the study groups. Corneal perforation of 1.6 and 1.1% occurred in SP and DP groups, respectively. Failed graft was reported 6 months postoperatively in 4 (1.6%) cases with SP and in 1 (1.1%) case with DP technique. Preoperative thickness profiles of UT-DSAEK tissues prepared from donated whole eyes via SP technique were not significantly different from those prepared with DP, showing a symmetric increase of thickness towards peripheral locations.

[Comparative analysis of modern methods of preparing donor material for endothelial keratoplasty]. / Sravnitel'naia otsenka sovremennykh sposobov podgotovki donorskogo materiala dlia éndotelial'noi keratoplastiki.

PURPOSE: To evaluate various methods of stripping Descemet's membrane of a donor corneoscleral flap for Descemet's membrane endothelial keratoplasty (DMEK). MATERIAL AND METHODS: The study included 60 corneoscleral flaps (mean donor age was 62.9 years) from the eye bank of Research Institute of Eye Diseases, which were not suitable for clinical use due to positive serological results. Four alternative methods of donor material dissection in preparation for DMEK were compared: SCUBA (group A), our newly suggested method utilizing intracapsular ring (group B), 'liquid bubble' (group C), 'big bubble' (group D). Parameters under evaluation were mean transplant preparation time, density of endothelial cells before and after dissection, presence of complications during detachment of Descemet's membrane. RESULTS: Mean detachment time in group A was 8.5 min, in group B - 7 min, in group C - 8 min, and in group D - 5 min. Loss of endothelial cells as compared with baseline was in average 10.5% in group A, 9.3% in group B, 10.7% in group C, and 10.3% in group D. Group A had two cases with complications occurring during separation of Descemet's membrane, group B had one such case, group C - 2 cases, and group D - 3 cases. Histologic examination confirmed absence of stromal fibers on the detached Descemet's membrane in groups A, B and C. CONCLUSION: Among the described methods of preparing donor material for DMEK surgery, all except 'big bubble' proved equal in terms of resulting transplant quality. The 'big bubble' dissection technique requires more time to complete, while the resulting transplant has stromal fibers. Our newly suggested method of Descemet's membrane stripping that utilizes intracapsular ring proved safe and effective alternative for preparing donor material for DMEK.

A Functional and Immunologic Point of View on Corneal Endothelial Transplantation: A Systematic Review and Meta-Analysis.

Background: To systematically review and meta-analyze the immunologic aspects and outcomes of various endothelial keratoplasty (EK) techniques, specifically comparing Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), Ultra-Thin Descemet's Stripping Automated Endothelial Keratoplasty (UT-DSAEK), and Descemet's Membrane Endothelial Keratoplasty (DMEK). Methods: Systematic review and meta-analysis. Main outcomes were the proportion of patients achieving a best spectacle-corrected visual acuity (BSCVA) of 20/20 at 6 months after keratoplasty, rejection rate one year after surgery, BSCVA at last follow up, and postoperative immunomodulating regimen. Results: A higher proportion of DMEK patients achieved a BSCVA of 20/20 after 6 months. UT-DSAEK and DMEK showed similar rejection rates with a lower risk of re-bubbling for UT-DSAEK (4% vs. 20%). Conclusions: DMEK showed faster visual recovery than UT-DSAEK but a similar rejection rate and long-term visual acuity. One-year postoperative slow tapering steroid regimen has a positive but not (yet) significant effect on rejection risk and visual outcomes.

Intraocular pressure-related side-effects after endothelial keratoplasty.

PURPOSE: To investigate circumpapillary retinal nerve fibre layer (RNFL) thickness, pupillary function and diameter after phacoemulsification and lens implantation alone or combined with endothelial keratoplasty (EK). METHODS: This study was a secondary analysis of data from a randomized, single-masked trial, that included 72 patients with Fuchs' endothelial dystrophy and cataract, equally allocated (1:1) to ultrathin Descemet's stripping automated endothelial keratoplasty or Descemet's membrane endothelial keratoplasty. The cataract extraction (CE) group included 40 patients undergoing cataract surgery only. All patients were treated with phacoemulsification and lens implantation. RESULTS: RNFL thickness was significantly lower in the CE group than after EK for the global (p < 0.01), nasal (p = 0.04), and temporal sectors (p = 0.01) 12 months after surgery. RNFL thickness was comparable between patients treated with rebubbling and others (p ≥ 0.16 for all comparisons) after 12 months. The CE group and patients treated with EK demonstrated a comparable scotopic (p = 0.34) and photopic pupil diameter (p = 0.95) as well as a comparable maximum (p = 0.83) and average pupillary constriction velocity (p = 0.95) after 12 months. In contrast, patients treated with rebubbling had a significantly smaller scotopic pupil diameter (p = 0.04). CONCLUSION: In this study, no evidence was found indicating a negative impact on the RNFL thickness after EK when compared to CE 12 months after surgery. Iris function and pupil diameter were comparable between the CE group and patients treated with EK after 12 months.

One-year Outcomes of Ultrathin Descemet Stripping Automated Endothelial Keratoplasty Combined with Cataract Surgery in the Korean Population.

PURPOSE: To evaluate the refractive outcomes after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) combined with phacoemulsification and intraocular lens implantation (triple procedure) in the South Korean population. METHODS: This retrospective observational study included 37 eyes of 36 patients who underwent the UT-DSAEK triple procedure between 2012 and 2021 in a single tertiary hospital. Preoperative and postoperative refractive outcomes and endothelial parameters at 1, 3, 6, and 12 months were observed. RESULTS: At the final postoperative 12-month period, the average best-corrected visual acuity was 0.4 ± 0.5 in logarithm of the minimum angle of resolution. The mean endothelial cell density at 12 months was 1,841.92 ± 731.24 cells/mm2, indicating no significant endothelial cell loss compared to the baseline (p = 0.128). The mean postoperative central corneal thickness at 12 months was 597.41 ± 86.26 µm. The postoperative mean absolute error at 12 months was 0.96 ± 0.89 diopters (D) and mean error was 0.89 ± 0.97 D. CONCLUSIONS: The results of our South Korean cohort study on UT-DSAEK triple surgery showed favorable and safe outcomes. Regardless of graft thickness, it should be noted that a hyperopic shift of 1.00 to 2.00 D needs to be considered in the case of UT-DSAEK triple surgery.

Hemi-Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (Hemi-UT-DSAEK) Using Pediatric Donor Corneas: A Case Series.

OBJECTIVE: We sought to evaluate the clinical outcomes of hemi-UT-DSAEK grafts from the pediatric donor corneas of patients affected by Fuchs Endothelial Corneal Dystrophy (FECD). METHODS: A prospective, interventional case series was conducted at the Ophthalmology Department of Venice Civil Hospital and the Veneto Eye Bank Foundation (Venice, Italy). Six eyes of six patients affected by FECD received large-diameter, semicircular hemi-UT-DSAEK grafts obtained from three pediatric donor corneas using the standard pull-through method. Endothelial cell density (ECD), central corneal thickness (CCT), best-corrected visual acuity (BCVA) and intraoperative and postoperative complications were recorded at different time intervals up to 12 months. RESULTS: The average donor age was 64.6 ± 8.6 years, and the pre-operative ECD was 3266 ± 225 cells/mm2. At 12 months postoperatively, the average ECD was 1376 ± 509 cells/mm2 with a mean decrease of 56.8 ± 19.1% from the preoperative donor count. At 12 months, four out of six eyes had significantly improved and reached a BCVA of ≥20/25 (Snellen equivalent). The mean CCT significantly decreased from 788 ± 138 µm before surgery to 576 ± 30 µm at 12 months postoperatively (p < 0.01). CONCLUSIONS: Hemi-UT-DSAEK grafts using pediatric donor corneas are surgically feasible and can provide similar clinical outcomes compared to conventional UT-DSAEK. Transplanting pediatric donor tissues with high ECD into two patients could potentially increase the donor tissue pool to treat endothelial disease.

Trial-based cost-effectiveness analysis of Descemet membrane endothelial keratoplasty (DMEK) versus ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK).

PURPOSE: To evaluate the cost-effectiveness of Descemet Membrane Endothelial Keratoplasy (DMEK) versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK). METHODS: A cost-effectiveness analysis using data from a multicenter randomized clinical trial was performed. The time horizon was 12 months postoperatively. Patients with Fuchs' endothelial dystrophy were randomized to DMEK (n = 29) or UT-DSAEK (n = 24). Relevant resources from healthcare and societal perspectives were included in the cost analysis. Quality-Adjusted Life Years (QALYs) were determined using the Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D-5L questionnaires. The main outcome was the incremental cost-effectiveness ratio (ICER; incremental societal costs per QALY). RESULTS: Societal costs averaged €8851 (US$11 406) for DMEK and €8320 (US$10 722) for UT-DSAEK. Higher costs in the DMEK group were mainly caused by higher rebubbling and regraft rates (21% and 7%, vs. 4% and 0% in the UT-DSAEK group). HUI3 QALYs were 0.70 (DMEK) and 0.79 (UT-DSAEK). EQ-5D-5L QALYs were 0.83 (DMEK) and 0.86 (UT-DSAEK). The ICER indicated DMEK was dominated by UT-DSAEK in both analyses. The cost-effectiveness probability for DMEK ranged from 21% to 5% (HUI3 QALYs) and 27%-14% (EQ-5D-5L QALYs), assuming the maximum acceptable ICER ranged from €2500 to €80.000 (US$3222-US$103 093) per QALY. CONCLUSION: The base case cost-effectiveness analysis favoured UT-DSAEK over DMEK, as costs of DMEK were higher while QALYs were lower. Further studies are required to assess long-term rebubbling and regraft rates and graft survival.

Ultrathin-Descemet Stripping Automated Endothelial Keratoplasty Versus Descemet Membrane Endothelial Keratoplasty: A Systematic Review and Meta-analysis.

BACKGROUND/AIM: The aim of this meta-analysis was to compare the efficacy and safety of Ultrathin - Descemet stripping automated endothelial keratoplasty (UT-DSAEK) versus Descemet membrane endothelial keratoplasty (DMEK) for the treatment of corneal endothelial failure in patients with Fuchs endothelial dystrophy (FED) or Pseudophakic bullous keratopathy (PBK). PATIENTS AND METHODS: We performed a meta-analysis and conducted a literature search in PubMed and Cochrane Library, following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Effects were calculated as odds ratios or standardized mean differences. RESULTS: A total of six studies with 300 eyes in total (151 UT-DSAE and 149 DMEK) were included. BSCVA was superior in the DMEK group compared with the UT-DSAEK at 3, 6, and 12 months after surgery. Rebubbling rates and overall adverse events were 2.37 and 1.48 times, respectively, higher in the DMEK group. The central corneal thickness and spherical equivalent were significantly lower in the DMEK group 12 months post-surgery. Endothelial cell density values were similar in both groups up to 12 months postoperatively. CONCLUSION: To the best of our knowledge, this is the first meta-analysis comparing UT-DSAEK with DMEK. DMEK surgery resulted in significantly better BSCVA at 3, 6, and 12 months postoperatively compared to UT-DSAEK. UT-DSAEK had a better complication profile with lower rebubbling rates.

[Risk factors for failure of pre-cut eye bank UT-DSAEK grafts]. / Évaluation des greffes UT-DSAEK prédécoupées en banque multi-tissus.

INTRODUCTION: The main risk factors for graft failure in penetrating keratoplasty are well known. However, few studies have examined donor characteristics or more precise data on endothelial keratoplasty. MATERIALS AND METHODS: This was a retrospective, single-center study at the Nantes University Hospital, aiming to identify factors predictive of one-year success or failure of eye bank UT-DSAEK endothelial keratoplasty grafts prepared between May 2016 and October 2018. The outcome measure was success or failure at 12months post keratoplasty. RESULTS: One hundred and five grafts were included: 93 successes and 12 failures at 12months. The failure rate was higher in 2016 compared to 2017 and 2018. The characteristics associated with higher failure rate were elderly donor, shorter time between harvesting and grafting, lower endothelial cell density, significant pre-graft endothelial cell loss, re-graft for Fuchs dystrophy, history of corneal transplant. DISCUSSION: Our results are consistent with those in the literature. However, some factors, such as the type of corneal harvesting or pre-graft endothelial cell loss, were not found. UT-DSAEK has demonstrated better results than DSAEK, but still appears to be somewhat inferior to DMEK. CONCLUSION: The main factor for graft failure in our study was an early re-graft within 12months. However, the low incidence of graft failure limits interpretation of these results.

Is ultra-thin Descemet stripping automated endothelial keratoplasty a viable alternative to Descemet membrane endothelial keratoplasty? A systematic review and meta-analysis.

Background: Ultra-thin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) is a recently developed surgical procedure that has shown promising results for the management of various corneal endothelial diseases. Objectives: To evaluate the outcomes of the UT-DSAEK to the Descemet membrane endothelial keratoplasty (DMEK). Design: A systematic analysis of the studies comparing UT-DSAEK with DMEK by evaluating one or more outcomes (vision, complications, and post-operative endothelial cell counts) was performed. The meta-analysis was done if two or more studies reported a common outcome. Methods: We used PubMed, EMBASE, and SCOPUS databases to identify articles comparing the outcomes of UT-DSAEK with DMEK and performed a meta-analysis using RevMan, version 5.4. Results: A total of six studies were included in this review (two randomized clinical trials and four non-randomized comparative studies). Our analysis showed the patients who underwent DMEK cases showed better visual outcomes with a mean difference of 0.06 LogMAR (95% CI: 0.04-0.09) in BCVA, albeit with i 2 of 52% (heterogenous values). The evidence was weak, with the most weightage on retrospective studies. UT-DSAEK showed significantly fewer complications such as graft dislocations, with an odds ratio of 0.25 (95% CI: 0.13-0.48). There was no significant difference in the endothelial cell counts with a mean difference of 86.34 (95%CI: -133.09 to -305.77). Conclusion: Although the literature is limited on UT-DSAEK with post-operative visual acuity that could be practically at par with DMEK, lesser complication rates and comparable post-operative endothelial cells could be a suitable alternative to DMEK for corneal endothelial pathologies.

Comparative Analysis of Corneal Parameters in Swept-Source Imaging between DMEK and UT-DSAEK Eyes.

BACKGROUND: The need to provide a comparative analysis of corneal parameter changes compared to their preoperative values between Descemet membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) patients. METHODS: The study included 24 eyes after UT-DSAEK and 24 eyes after DMEK. Visual acuity, endothelial cell count (ECC), central corneal thickness (CCT), mean keratometry (MK), mean astigmatism (MA), astigmatism asymmetry (AA) and higher-order aberrations (HOAs) were assessed at baseline and 1, 3, 6 and 12 months after the surgery. RESULTS: From the 3rd month post operation, ECC was higher in the DMEK eyes than in the UT-DSAEK eyes (p = 0.01). In a bivariate analysis that was adjusted for age, DMEK was associated with a smaller decrease in posterior MK at the 1-month (ß = -0.49, p = 0.002), 3-month (ß = -0.50, p < 0.001), 6-month (ß = -0.58, p < 0.001) and 12-month (ß = -0.49, p < 0.001) follow-up visits. There were no significant differences in changes in anterior or combined surface MK throughout the observation period. Accordingly, no significant differences in changes in MA, AA or HOAs compared to the baseline values were identified between the eyes after DMEK and UT-DSAEK at any follow-up time point. CONCLUSIONS: UT-DSAEK seemed to be an easier and safer technique than DMEK while maintaining similar outcomes regarding irregular astigmatism and total keratometry values.

[UT-DSAEK using grafts provided by a tissue bank, a one-year follow-up study of 79 grafts]. / UT-DSAEK avec greffons préparés en banque, suivi de 79 greffes sur un an.

INTRODUCTION: UT-DSAEK is a recent technique developed in order to obtain grafts thinner than a conventional DSAEK (less than 100 microns). The goal of this study was to evaluate the anatomic and clinical results over a period of one year for a retrospective series of UT-DSAEK procedures at the University Hospital of Nantes, using pre-cut grafts provided by a tissue bank, and to compare results with other existing techniques: DSAEK and DMEK. METHODS: In this retrospective, single-center study, all patients requiring an endothelial graft over a one-year period were included. The criteria studied were visual acuity, graft thickness, pachymetry and specular microscopy, recorded on the preoperative visit, D7, M1, M3, M6 and M12. RESULTS: Seventy-nine grafts were performed on 75 patients. The mean age was 72 years. Between the 7th day and the end of the first year, the graft thickness in the visual axis decreased from 75±29 to 60±21 microns rapidly over the first three months. The pachymetry decreased from 706±95 microns preoperatively to 561±54 microns with the same kinetics. The cell density of the graft decreased from 2604±13 cell/mm2 prior to the procedure to 1551±124 cell/mm2 (40% loss) at one year. The preoperative visual acuity was 1.16 logMAR, rapidly improving to 0.65 logMAR at the first month and 0.40 logMAR at one year. CONCLUSION: This study provides a fair amount of data on the progression of UT-DSAEK grafts: a decrease in graft thickness over the first three months, corresponding to an increase in visual acuity over this same period, with a good endothelial survival rate. This technique opens new avenues for the treatment of endothelial diseases, being complementary to DMEK in terms of surgical indications.

Rebubbling rate in preloaded versus surgeon prepared DSAEK.

PURPOSE: To compare the clinical outcomes of eye bank preloaded Descemet stripping automated endothelial keratoplasty (DSAEK) grafts and surgeon prepared. METHODS: In this retrospective study, the data were obtained from two groups (a) surgeon cut DSAEK where tissue was prepared by the surgeon immediately before surgery, and (b) preloaded DSAEK tissue shipped to the surgeon after preparation by the eye bank. Standard DSAEK preparations using Moria microkeratome with single pass method were performed. For the tissues prepared by the eye banks, they were preloaded in an iGlide device and shipped in transport media. Standard DSAEK surgery using bimanual pull-through technique was performed for all the grafts. Air was used as a tamponade. Main outcome measures included best corrected visual acuity (BCVA) and rebubbling rate. RESULT: Out of 107 eyes of 101 patients that underwent DSAEK surgery, 33 tissues were prepared by the surgeon (sc-DSAEK), while 74 were prepared by the eye bank (pl-DSAEK). sc-DSAEK showed a rebubbling rate of 9.1%, compared to the 16.2% for the preloaded DSAEK (p = 0.11). There was no statistical difference in postoperative BCVA between the two groups. Logistic regression analysis showed no association between detachment rate and cataract surgery, graft preparation method, graft diameter and reason for graft. CONCLUSION: Preloaded grafts have similar rebubbling rate and visual acuity achieved compared with surgeon prepared grafts.

Ultrathin Descemet stripping automated endothelial keratoplasty versus Descemet membrane endothelial keratoplasty: a fellow-eye comparison.

BACKGROUND: To compare the visual outcome and patients' satisfaction after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) performed on fellow eyes of the same patients. METHODS: In this retrospective study, the records of 18 pseudophakic patients affected by Fuchs endothelial dystrophy who underwent DMEK in one eye and UT-DSAEK in the fellow eye were reviewed. Best corrected visual acuity (BCVA), corneal pachymetry, keratometry, corneal aberrations, photopic and mesopic contrast sensitivity, and endothelial cell counts measured 12 months after surgery in either eye were analyzed and compared. The results of a satisfaction questionnaire were also reviewed. RESULTS: Twelve months after surgery, BCVA was not significantly different in UT-DSAEK and DMEK eyes (0.10 ± 0.04 and 0.07 ± 0.07 logMAR, respectively); at both 4- and 6 mm optical zones total and posterior corneal higher order aberrations (HOAs), posterior astigmatism and total coma were significantly lower after DMEK; BCVA in both groups was significantly correlated mainly with anterior corneal aberrations; contrast sensitivity was higher after DMEK especially in mesopic conditions and at medium spatial frequencies; the endothelial cell density was similar, although slightly higher in the UT-DSAEK group (p = 0.10). The satisfaction questionnaire showed that although patients were highly satisfied from both procedures, more than half of them preferred DMEK and reported a more comfortable and quicker postoperative recovery. CONCLUSIONS: DMEK and UT-DSAEK showed no evidence of difference in terms of postoperative BCVA, although DMEK had a better performance in terms of contrast sensitivity, posterior corneal aberrations and overall patient satisfaction.