Descemet Membrane Endothelial Keratoplasty versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty: A Multicenter Randomized Controlled Clinical Trial

Ultrathin DSAEK versus DMEK - Review of systematic reviews

The efficacy and safety of Descemet's membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) have been recently compared in several systematic reviews (SRs). The aim of this study was to assess the evidence quality of such SRs, in order to obtain a scientifically rigorous comparison between the two techniques. We performed a systematic review of SRs and meta-analyses comparing the efficacy and safety between UT-DSAEK and DMEK up to 24th March 2023, using 3 electronic databases (PubMed, Cochrane Library, Google Scholar) plus manual reference search. Specific outcomes analyzed included best-corrected visual acuity (BCVA), endothelial cell density (ECD), rebubbling rate, and other postoperative complications. Of 90 titles/abstracts screened, four SRs met the inclusion criteria. All SRs adequately analyzed potential bias of the included studies. One SR raised concern for potential literature search bias and two SRs have heterogeneity in some outcomes analyzed. All SRs found higher BCVA after DMEK, but one SR reported significant heterogeneity. All SRs found significant heterogeneity in ECD analysis, with one SR providing inconsistent analysis of this outcome. Three SRs analyzed rebubbling rates, favoring UT-DSAEK over DMEK. Three SRs concluded a higher overall complication rate after DMEK, although rebubbling may be a confounding factor. This systematic review clarifies the strengths and weaknesses of published SRs and reinforces the conclusion that DMEK leads to superior visual outcomes compared to UT-DSAEK, with the trade-off of higher rebubbling rates and possibly other postoperative complications. Studies with longer follow-up are needed to ascertain these differences between procedures.

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.

Principal Component Analysis of a Real-World Cohort of Descemet Stripping Automated Endothelial Keratoplasty and Descemet Membrane Endothelial Keratoplasty Cases: Demonstration of a Powerful Data-Mining Technique for Identifying Areas of Research

PURPOSE

Principal component analysis (PCA) is a descriptive exploratory statistical technique that is widely used in complex fields for data mining. However, it is rarely used in ophthalmology. We explored its research potential with a large series of eyes that underwent 3 keratoplasty techniques: Descemet membrane endothelial keratoplasty (DMEK), conventional Descemet stripping automated endothelial keratoplasty (ConDSAEK), or ultrathin-DSAEK (UT-DSAEK).

METHODS

All consecutive DMEK/DSAEK cases conducted in 2016 to 2022 that had ≥24 months of follow-up were included. ConDSAEK and UT-DSAEK were defined as preoperative central graft thickness ≥130 and <130 μm, respectively. Seventy-six patient, disease, surgical practice, and temporal outcome variables were subjected to PCA, including preoperative anterior keratometry, the use of sulfur hexafluoride gas (SF6) versus air for primary tamponade, and postoperative best corrected visual acuity and endothelial cell density. Associations of interest that were revealed by PCA were assessed with the Welch t test or Pearson test.

RESULTS

A total of 331 eyes were treated with DMEK (n = 165), ConDSAEK (n = 95), or UT-DSAEK (n = 71). PCA showed that ConDSAEK and UT-DSAEK clustered closely, including regarding postoperative best corrected visual acuity, and were clearly distinct from DMEK. PCA and follow-up univariate analyses suggested that in DMEK, 1) flatter preoperative anterior keratometry (average, K1, and K2) associated with more rebubbling (P = 0.004-0.089) and graft detachment (P = 0.007-0.022); 2) graft marking did not affect postoperative ECD; and 3) lower postoperative endothelial cell density associated with SF6 use (all P > 0.001) and longer surgery (P = 0.005-0.091). All associations are currently under additional investigation in our hospital.

CONCLUSIONS

PCA is a powerful technique that can rapidly reveal clinically relevant associations in complex ophthalmological datasets.

Visual function after ultrathin Descemet's stripping automated endothelial keratoplasty or Descemet's membrane endothelial keratoplasty combined with cataract surgery: a randomised controlled clinical trial

AIMS

To compare best-corrected visual acuity (BCVA), contrast sensitivity and endothelial cell density (ECD) after ultrathin Descemet's stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK).

METHODS

A randomised, single-blinded, single-centre design was used. 72 patients with Fuchs' endothelial dystrophy and cataract were randomised to UT-DSAEK or DMEK combined with phacoemulsification and lens implantation. 27 patients with cataract were included in a control group and treated with phacoemulsification and lens implantation. The primary outcome was BCVA at 12 months.

RESULTS

Compared with UT-DSAEK, DMEK resulted in better BCVA with mean differences of 6.1 early treatment diabetic retinopathy study (ETDRS) (p=0.001) after 3 months, 7.4 ETDRS (p<0.001) after 6 months and 5.7 ETDRS (p<0.001) after 12 months. The control group obtained significantly better BCVA with a mean difference of 5.2 ETDRS (p<0.001) compared with DMEK 12 months postoperatively. Compared with UT-DSAEK, contrast sensitivity was significantly better 3 months after DMEK with a mean difference of 0.10 LogCS (p=0.03). However, our study found no effect after 12 months (p=0.08). ECD was significantly lower after UT-DSAEK compared with DMEK with mean differences of 332 cells/mm2 (p<0.01) after 3 months, 296 cells/mm2 (p<0.01) after 6 months and 227 cells/mm2 (p=0.03) after 12 months.

CONCLUSIONS

Compared with UT-DSAEK, DMEK resulted in better BCVA 3, 6 and 12 months postoperatively. Twelve months postoperatively, DMEK had a higher ECD than UT-DSAEK; however, no difference in contrast sensitivity was found.

TRIAL REGISTRATION NUMBER

NCT04417959.

Descemet's membrane endothelial keratoplasty is the predominant keratoplasty procedure in Germany since 2016: a report of the DOG-section cornea and its keratoplasty registry

BACKGROUND/AIMS

This retrospective multicentric panel study provides absolute numbers, types of and indications for corneal transplantation in Germany from 2011 to 2021 and sets them into the international context.

METHODS

A questionnaire was sent to the 104 German ophthalmologic surgery departments and 93 (89%) provided their data.

RESULTS

The number of reported keratoplasties more than doubled from 2011 (n=4474) to 2021 (n=8998). Lamellar keratoplasties (49% posterior (n=2883), 4% anterior (n=231)) surpassed penetrating keratoplasty (PKP, 47%, n=2721) for the first time in 2014. Since 2016, Descemet's membrane endothelial keratoplasty (DMEK) has become the predominant keratoplasty procedure in Germany. Its number increased by 1.5-fold from 3850 (2016) to 5812 (2021). Main indications in 2021 were Fuchs' endothelial corneal dystrophy (FECD, 43%), pseudophakic corneal decompensation (12%), repeated keratoplasty (11%), infections (7%), keratoconus (6%) and corneal scarring (4%, others: 9%). The PKP percentage decreased from 70.2% in 2011 (n=3141) to 31.7% in 2021 (n=2853). Descemet's stripping (automated) endothelial keratoplasties (DSAEKs) decreased to 1% in 2021 (n=74). 98.6% of all posterior lamellar keratoplasties were DMEKs in Germany in 2021. The number of deep anterior lamellar keratoplasties (DALKs) remained comparable from 2011 (n=269) to 2021 (n=251, 2.8%).

CONCLUSION

Main indications for corneal transplantation in Germany (2021) were FECD and pseudophakic corneal decompensation. DMEK is by far the predominant corneal transplantation procedure since 2016 followed by PKP, whose absolute number decreased only slightly during the decade from 2011 to 2021. DALK proportions remain low, but stable, whereas DSAEK decreased annually and plays a minor role in Germany.

TRIAL REGISTRATION NUMBER

NCT03381794.

Cost-effectiveness of the ADVISE trial: An intraoperative OCT protocol in DMEK surgery

The intraoperative optical coherence tomography (iOCT) is recently introduced in Descemet membrane endothelial keratoplasty (DMEK) surgery, which aims to increase clinical performance and surgery safety. However, the acquisition of this modality is a substantial investment. The objective of this paper is to report on the cost-effectiveness of an iOCT-protocol in DMEK surgery with the Advanced Visualization in Corneal Surgery Evaluation (ADVISE) trial. This cost-effectiveness analysis uses data 6 months postoperatively from the multicentre prospective randomized clinical ADVISE trial. Sixty-five patients were randomized to usual care (n = 33) or the iOCT-protocol (n = 32). Quality-Adjusted Life Years (EQ-5D-5L), Vision-related Quality of Life (NEI-VFQ-25) and self-administered resources questionnaires were administered. Main outcome is the incremental cost-effectiveness ratio (ICER) and sensitivity analyses. The iOCT protocol reports no statistical difference in ICER. For the usual care group compared with the iOCT protocol, respectively, the mean societal costs are €5027 compared with €4920 (Δ€107). The sensitivity analyses report the highest variability on time variables. This economic evaluation learned that there is no added value in quality of life or cost-effectiveness in using the iOCT protocol in DMEK surgery. The variability of cost variables depends on the characteristics of an eye clinic. The added value of iOCT could gain incrementally by increasing surgical efficiency, and aiding in surgical decision-making.

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.

Initial results of DMEK combined with cataract surgery and implantation of the light-adjustable lens

PURPOSE

To evaluate the use of light-adjustable intraocular lenses (LALs) to maximize visual acuity (VA) postoperatively in eyes undergoing combined Descemet membrane endothelial keratoplasty (DMEK) and cataract surgery.

SETTING

Private practice, tertiary referral center.

DESIGN

Retrospective review of initial case series.

METHODS

Patients with Fuchs endothelial dystrophy had DMEK combined with phacoemulsification and LAL implantation. Lenses were adjusted based on postoperative manifest refraction and locked-in 3 to 6 months postoperatively. Adjustments to the LAL were started after stabilization of refraction at sequential examinations. Outcomes were uncorrected near and distance VA and manifest refraction 3 to 6 months after locking the lens.

RESULTS

A total of 27 eyes in 17 patients with mean age of 65 years (range 53 to 75 years) were included in this study. 6 eyes (22%) had either a near or intermediate target, and 21 eyes (78%) had a distance target. After lock-in, 57% of eyes with a distance target had uncorrected distance VA (UDVA) of 20/20 or better, 90% were 20/25 or better, and 100% were 20/40 or better. After lens lock-in, 100% of eyes had corrected distance VA (CDVA) of 20/20 or better, 86% had postoperative UDVA the same or better than preoperative CDVA, and 100% of eyes had UDVA within 1 line of the preoperative CDVA. In total, 93% of eyes were within 1 diopter (D) of spherical target, and 93% of eyes had ≤0.5 D of refractive cylinder postoperatively.

CONCLUSIONS

Combining DMEK with LAL implantation provided significantly better UDVA and refractive outcomes than previously reported data on combined implantation of a standard monofocal lens.

Comparison of Long-Term Outcomes of DSEK and DMEK in Fuchs Endothelial Dystrophy

PURPOSE

This study aimed to compare the long-term endothelial cell loss, graft survival, and clinical outcomes in patients with Fuchs endothelial dystrophy (FED) after Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK) using a standardized surgical protocol.

METHODS

Three hundred and six consecutive DSEK and DMEK grafts of 223 patients with FED performed by 8 surgeons between January 2006 and August 2022 were analyzed. The primary outcome measures were graft survival, endothelial cell loss, and best spectacle-corrected visual acuity.

RESULTS

At 5 years, graft survival was 96% for both DSEK and DMEK eyes. The mean percentage of endothelial cell loss was 57.7 ± 17.1 in DSEK and 56.8 ± 15.2 in DMEK eyes ( P = 0.430). The mean best spectacle-corrected visual acuity was 0.13 ± 0.14 logMAR in DSEK and 0.01 ± 0.18 logMAR in DMEK grafts ( P <0.00001) at 5 years postoperatively. Rebubbling was performed in 7.8% DSEK and 2.1% DMEK grafts ( P = 0.441). Cox regression identified rejection episodes (HR 6.5; 95% CI: 1.70-24.8; P = 0.0062) as a significant contributing factor for graft failure.

CONCLUSIONS

DMEK had superior visual acuity outcomes compared with DSEK in these patients up to 5 years after surgery. At 5 years, there was no significant difference in graft survival or endothelial cell loss between DSEK and DMEK eyes with FED. We propose that our standardized technique reduces the need for rebubbling.

Ten-Year Changes in Vision, Refractive Error, and Corneal Thickness After Descemet Stripping Automated Endothelial Keratoplasty for Fuchs Endothelial Corneal Dystrophy

PURPOSE

The goal of this study was to determine changes in best-corrected visual acuity (BCVA), refractive error, and central corneal thickness (CCT) during the first decade after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

Outcomes of all consecutive eyes undergoing DSAEK for Fuchs endothelial corneal dystrophy (FECD) were reviewed; eyes with untreatable comorbidities before DSAEK were excluded. DSAEK was performed through a temporal incision and all eyes were pseudophakic postoperatively. Changes in BCVA, manifest spherical equivalent, manifest cylinder (vector analysis), and CCT were assessed by using generalized estimating equation models.

RESULTS

BCVA improved between 6 months (0.18 ± 0.12 logarithm of the minimum angle of resolution (logMAR); Snellen equivalent, 20/30) and 5 years (0.10 ± 0.10 logMAR; 20/25; n = 74, P < 0.001) and then remained stable at 10 years (0.09 ± 0.10 logMAR, n = 48, P = 0.22). There was a myopic shift of -0.20 ± 0.51 D between 6 months and 5 years (n = 65, P = 0.002) that remained stable at 10 years (-0.09 ± 0.44 D; 20/25; n = 34, P = 0.33). Manifest cylinder drifted with-the-rule between 6 months and 5 years (n = 65, P < 0.001) and between 5 and 10 years (n = 34, P < 0.001). CCT was stable between 6 months (672 ± 57 μm) and 5 years (677 ± 55 μm, n = 67, P = 0.47), but increased at 10 years (702 ± 60 μm, n = 39, P = 0.001).

CONCLUSIONS

Excellent BCVA can be achieved during the first decade after DSAEK for FECD, although improvement seems to plateau after 5 years. Changes in manifest refractive error were not clinically significant. The gradual increase in CCT was consistent with longer-term changes found after other types of keratoplasty.

Development of Thermoplastic Polyurethane Films for the Replacement of Corneal Endothelial Function of Transparency Maintenance

Endothelial keratoplasty is the main surgical procedure for treating corneal endothelial dysfunction (CED), which is limited by the global shortage of donor corneas. Herein, we developed and evaluated the modified thermoplastic polyurethane (M-TPU) films with gelatin-glycidyl methacrylate to replace the corneal endothelial function and maintain corneal transparency. The films displayed comparable light transmission characteristics with normal corneas and clinically favorable mechanical properties for surgical manipulation. After surface modification, the hydrophilicity and biocompatibility of M-TPU films were significantly improved. In the rabbit CED model, the M-TPU implants exhibited firm adhesion to the exposed stromal surface. The rabbit corneal transparency and thickness could be restored completely within 1 week of M-TPU film implantation. There was no significant inflammatory reaction and immune rejection during the follow-up of 1 month. Proteomic analysis suggested that the complement inhibition, the increase of mineral absorption, and the decrease of P53 apoptosis signaling pathway and lysine degradation might be beneficial in maintaining the corneal transparency. Overall, our study demonstrated the potential of M-TPU films as artificial implants for the replacement of corneal endothelial function to restore corneal thickness and transparency.

Descemet Stripping Automated Endothelial Keratoplasty versus Descemet Membrane Endothelial Keratoplasty for Fuchs Endothelial Corneal Dystrophy: A National Registry-Based Comparison

PURPOSE

To compare the outcome between posterior lamellar corneal transplant procedures for Fuchs endothelial corneal dystrophy, taking preoperative patient characteristics in consideration. Surgical methods compared were Descemet membrane endothelial keratoplasty (DMEK), Descemet stripping automated endothelial keratoplasty (DSAEK), and DSAEK with concomitant cataract surgery (phacoemulsification plus DSAEK).

DESIGN

Registry-based study with propensity score matching.

PARTICIPANTS

One thousand six hundred seventy-seven patients from all Swedish corneal transplantation units treated from 2012 through 2019.

METHODS

All patients undergoing endothelial keratoplasty performed from 2012 through 2019 with completed 2-year follow-up data reported to The Swedish Corneal Transplant Register were included, totaling 1677 patients. Three comparable groups (DMEK, DSAEK, and phacoemulsification plus DSAEK) with 216 patients in each group were generated with propensity score matching based on preoperative visual acuity, age, sex, year of surgery, and preoperative risk factors such as inflammation, vascularization, and glaucoma.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA) at the 2-year follow-up, frequency of graft dislocation, graft rejection episodes, and graft failure within 2 years including primary graft failure.

RESULTS

The preoperative corneal status was affected more severely in the DSAEK group before matching. In the matched groups, the median BCVA 2 years after surgery was 0.1 logarithm of the minimum angle of resolution (logMAR) in both the DMEK and the phacoemulsification plus DSAEK groups and 0.15 logMAR in the DSAEK group (P = 0.001). The frequency of graft dislocation was higher among the patients undergoing phacoemulsification plus DSAEK, but the frequency of graft failure and primary graft failure was higher in the DMEK group.

CONCLUSIONS

Visual acuity improved in most patients (90%) with all 3 surgical methods. However, DMEK and phacoemulsification plus DSAEK reached higher levels of visual acuity 2 years after surgery, and phacoemulsification plus DSAEK was superior considering graft survival rate. All 3 surgical procedures showed both strengths and weaknesses, suggesting that the choice of surgical method should be individualized, taking into consideration not only the cornea, but each patient's complete medical status as well as the entire course of postoperative medical care.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Efficacy and safety of UT-DSAEK combined with Carlevale's sutureless scleral fixation IOL

PURPOSE

To evaluate a novel surgical combination of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and sutureless scleral fixation for Carlevale intraocular lens (SSF-Carlevale IOL) implantation to manage corneal endothelial decompensation when there is a concomitant need for secondary IOL fixation.

METHODS

Clinical data collected from 10 eyes of 9 patients with bullous keratopathy (BK) who underwent combined UT-DSAEK and SSF-Carlevale IOL implantation in a single procedure were retrospectively analyzed. Anterior chamber IOL (4 cases), aphakia (4 cases, 1 of which associated with PEX), and previous trauma (2 cases) were the conditions responsible for BK. Corrected distance visual acuity (CDVA), intraocular pressure (IOP), endothelial cell density (ECD), central corneal thickness (CCT), graft thickness (GT) and complications were recorded over a 12-month follow-up period.

RESULTS

In 90% (9/10) of eyes graft clarity was maintained during follow-up. The mean CDVA improved significantly (p < 0.0001) from 1.78 ± 0.76 logMAR preoperatively to 0.53 ± 0.3 logMAR at 12 months. ECD on average decreased from 2575 ± 125.3 cells/mm2 (donor tissue) to 1697 ± 133.3 cells/mm2 in 12 months. The mean CCT decreased from 870 ± 200 µm to 650 µm ± 9 at 12 months (ANOVA, p = 0.0005).

CONCLUSIONS

Combined UT-DSAEK and SSF-Carlevale IOL implantation was associated with good corneal graft survival and IOP control, with few complications. These findings suggest that this surgical approach is a practical option for patients requiring both treatment for corneal endothelial dysfunction and secondary IOL implantation.

Descemet membrane endothelial keratoplasty compared with ultrathin Descemet stripping automated endothelial keratoplasty: a meta-analysis

AIMS

This study aims to compare the clinical outcome of Descemet membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) in patients with corneal endothelial dysfunction due to Fuchs' endothelial dystrophy or pseudophakic bullous keratopathy.

METHODS

We conducted a meta-analysis using a literature search of Embase, PubMed, Cochrane CENTRAL, ClinicalTrials.gov and WHO ICTRP databases. We included randomised controlled trials (RCTs) and cohort studies that compared DMEK and UT-DSAEK (graft<130 µm), with a follow-up of ≥12 months, published until 20 February 2022. We used the Revised Cochrane risk-of-bias tool for RCTs and the Risk of Bias in Non-Randomised Studies-of Interventions system for cohort studies.

RESULTS

Out of 144 records, 8 studies (3 RCTs, 2 fellow-eye studies and 3 cohort studies) were included, encompassing 376 eyes, (N=187 DMEK vs N=189 UT-DSAEK). The 12-month logarithm of the minimum angle of resolution best-corrected visual acuity (BCVA) was better post-DMEK (mean difference -0.06 (95% CI -0.10 to -0.02)), but with higher rebubbling risk: OR 2.76 (95% CI 1.46 to 5.22). Heterogeneity was significant I2=57%. Findings were consistent when excluding retrospective studies, including only studies with low risk of bias or RCTs only. An analysis of studies with mean DSAEK grafts <70 µm showed no significant difference in BCVA between the procedures. Publication bias was found in the BCVA analysis (Egger's test p=0.023).

CONCLUSIONS

Post-DMEK BCVA is superior to post-UT-DSAEK when using <130 µm grafts. DSAEK grafts <70 µm may not significantly differ from DMEK. The higher risk of rebubbling with DMEK necessitates an appropriate selection of patients.

PROSPERO REGISTRATION NUMBER

CRD42022340805.

Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK) versus Descemet Membrane Endothelial Keratoplasty (DMEK)-a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Endothelial keratoplasty (EK) is a commonly performed transplant procedure used in the treatment of corneal endothelial dysfunction. The aim of this systematic review and meta-analysis is to evaluate the differences in visual acuity outcomes, endothelial cell density (ECD) and complications between two forms of EK, ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

A literature search of MEDLINE, Embase and Cochrane Library was conducted to identify studies reporting comparative results of UT-DSAEK versus DMEK. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was used for search strategy. Of 141 titles, 7 studies met the inclusion criteria; best corrected visual acuity (BCVA) (LogMAR), ECD (cells/mm2), and complications were compared, with all statistical analysis performed using Review Manager.

RESULTS

A total of 362 eyes were included for analysis. DMEK resulted in significantly better BCVA at 3 months (0.14 vs 0.22, p = 0.003), 6 months (0.08 vs 0.18, p = 0.005) and 1 year post-op (0.07 vs 0.14, p = 0.0005). UT-DSAEK resulted in significantly lower total complications (25.2% vs 57.3%, p = 0.0001) and rates of re-bubbling (11.0% vs 33.7%, p = 0.004). No differences were found in ECD between the two procedures (1541 vs 1605, p = 0.77).

CONCLUSIONS

DMEK results in superior visual acuity rates with quicker recovery. However, UT-DSAEK has a more favourable complication profile, particularly regarding lower rates of re-bubbling. Both are valuable options in the treatment of corneal endothelial disease and choice of procedure may depend on surgical expertise.

Belgian Endothelial Surgical Transplant of the Cornea (BEST cornea) protocol: clinical and patient-reported outcomes of Ultra-Thin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK) versus Descemet Membrane Endothelial Keratoplasty (DMEK) - a multicentric, randomised, parallel group pragmatic trial in corneal endothelial decompensation

OBJECTIVES

Corneal blindness is the third most frequent cause of blindness globally. Damage to the corneal endothelium is a leading indication for corneal transplantation, which is typically performed by lamellar endothelial keratoplasty. There are two conventional surgical techniques: Ultra-Thin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK) and Descemet Membrane Endothelial Keratoplasty (DMEK). The purpose of this study is to compare both techniques.

METHODS AND ANALYSIS

The trial compares UT-DSAEK and DMEK in terms of clinical and patient reported outcomes using a pragmatic, parallel, multicentric, randomised controlled trial with 1:1 allocation with a sample size of 220 participants across 11 surgical centres. The primary outcome is the change in best-corrected visual acuity at 12 months. Secondary outcomes include corrected and uncorrected vision, refraction, proportion of high vision, quality of life (EQ-5D-5L and VFQ25), endothelial cell counts and corneal thickness at 3, 6 and 12 months follow-up appointments. Adverse events will also be compared 12 months postoperatively.

ETHICS AND DISSEMINATION

The protocol was reviewed by ethical committees of 11 participating centres with the sponsor centre issuing the final definitive approval. The results will be disseminated at clinical conferences, by patient partner groups and open access in peer-reviewed journals.

GOVERNANCE OF THE TRIAL

Both, trial management group and trial steering committee, are installed with representatives of all stakeholders involved including surgeons, corneal bankers, patients and external experts.

TRIAL REGISTRATION NUMBER

NCT05436665.

Refractive outcomes after DMEK: meta-analysis

In this meta-analysis and systematic literature review of refractive outcomes after Descemet membrane endothelial keratoplasty (DMEK), the extent of the refractive shift and an overview of reasons for refractive shift after DMEK are provided. The PubMed library was screened for articles containing the terms "Descemet membrane endothelial keratoplasty," "DMEK," "Descemet membrane endothelial keratoplasty combined with cataract surgery," "triple-DMEK" combined with "refractive outcomes," "refractive shift," and "hyperopic shift." The refractive outcomes after DMEK were analyzed and compared using a fixed and random effects model. The overall mean change of the spherical equivalent outcome when compared with the preoperative value in cases of DMEK or when compared with the preoperative target refraction in cases of DMEK combined with cataract surgery was +0.43 diopters (D) (95% CI, 0.31-0.55). When DMEK is combined with cataract surgery, a target refraction of -0.5 D is recommended to achieve emmetropia. Changes in the posterior corneal curvature are identified as the main cause of the refractive hyperopic shift.

Video Grading of Descemet Membrane Endothelial Keratoplasty Surgery to Identify Surgeon Risk Factors for Graft Detachment and Rebubbling: A Post Hoc Observational Analysis of the Advanced Visualization In Corneal Surgery Evaluation Trial

PURPOSE

The aim of this study was to explore video-graded intraoperative risk factors for graft detachment (GD) and rebubbling in Descemet membrane endothelial keratoplasty surgery.

METHODS

A post hoc analysis of 65 eyes of 65 pseudophakic subjects with Fuchs endothelial dystrophy that underwent Descemet membrane endothelial keratoplasty surgery as part of the Advanced Visualization In Corneal Surgery Evaluation trial. All surgical recordings were assessed by 2 graders using a structured assessment form. A multinominal regression was performed to estimate the independent effect of video-graded intraoperative factors on the incidence of GD and rebubbling. Secondary outcomes are corrected distance visual acuity and endothelial cell density.

RESULTS

In total, 33 GDs were recorded, of which 17 required rebubbling. No significant predictors for GD or rebubbling were identified. However, the results revealed 2 clinically relevant patterns. An unfavorable graft configuration (ie, wrinkled, tight scroll, or taco-shaped) and a gas-bubble size smaller than the graft diameter were associated with an increased risk of GD [odds ratio (OR) 2.5 and OR 2.26, respectively] and rebubbling (OR 2.0 and OR 2.60, respectively). Inversely, a larger gas-bubble size was associated with a reduced risk of GD (OR 0.37) and rebubbling (OR 0.36). At 3 and 6 months postoperatively, corrected distance visual acuity was poorer in subjects requiring a rebubbling and endothelial cell density loss was higher in subjects with a partial GD.

CONCLUSIONS

Our analysis revealed that the gas-bubble size and graft shape/geometry seem to be relevant clinical factors for GD and rebubbling, whereas descemetorhexis difficulty, degree of graft manipulation, graft overlap, and surgical iridectomy were not associated with an increased risk.

Descemet Membrane Endothelial Keratoplasty-Induced Refractive Shift and Descemet Membrane Endothelial Keratoplasty-Induced Intraocular Lens Calculation Error

PURPOSE

The aim of this study was to determine the mechanisms leading to the refractive shift and intraocular lens calculation error induced by Descemet membrane endothelial keratoplasty (DMEK), using ocular biometry and corneal elevation tomography data.

METHODS

This is a retrospective, monocentric cohort study. Eyes which underwent uncomplicated DMEK surgery with available pre-DMEK and post-DMEK Scheimpflug rotating camera data (Pentacam, Oculus, Wetzlar, Germany) were considered for inclusion with an age-matched control group of healthy corneas. Cataract surgery data were collected for triple-DMEK cases. DMEK-induced refractive shift (DIRS) and intraocular lens calculation error (DICE) were calculated. Pearson r correlation coefficient was calculated between each corneal parameter variation and both DIRS and DICE.

RESULTS

DIRS was calculable for 49 eyes from 43 patients. It was 30.61% neutral, 53.06% hyperopic (36.73% > 1D), and 16.32% myopic (6.12% > 1 D). DICE was calculable for 30 eyes of 26 patients: It was 46.67% neutral, 40.00% hyperopic (10.00% > 1D), and 13.33% myopic (3.33% > 1D). DIRS and DICE were mainly associated with variations in PRC/ARC ratio, anterior average radii of curvature (ARC), posterior average radii of curvature (PRC), and posterior Q.

CONCLUSIONS

Our results suggest that ARC variations, PRC/ARC ratio variations, PRC variations, and posterior Q variations are the most influential parameters for both DIRS and DICE. We suggest that a distinction between those different phenomenons, both currently described as "hyperopic shift" in the literature, should be made by researchers and clinicians.

Donor lamella thickness after ultrathin Descemet stripping automated endothelial keratoplasty and its relation to postoperative visual acuity and pre-operative lamella measures

BACKGROUND

To accurately measure ultrathin Descemet stripping automated endothelial keratoplasty (DSAEK) donor lamella thickness during the first postoperative year and to correlate this with pre-operative and other postoperative measurements.

METHODS

Donor lamella thickness in 41 eyes undergoing DSAEK for Fuchs endothelial dystrophy (FED) was measured using the Tomey Casia OCT directly after graft preparation and at 1 week and 1, 3, 6 and 12 months postoperatively. Visual acuity and endothelial cell density were measured as the secondary parameters.

RESULTS

Individual graft thickness profiles were shown to be fairly regular within the optically relevant area. There was a strong and highly significant correlation between the pre- and postoperative lamellar thicknesses at all time points (p < 0.0001). Compared with the measurements directly after preparation at the cornea bank, the lamella thickness decreased by 12% after 12 months. Between 1 and 12 months postoperatively, the lamella thickness (mean ± SD) changed from 112 ± 27 μm to 101 ± 21 μm. Best spectacle-corrected visual acuity (BSCVA) changed from 0.46 ± 0.30 logMAR pre-operatively through 0.36 ± 0.33 at 1 month to 0.13 ± 0.16 at 1 year postoperatively. The endothelial cell counts were comparable to those reported in previous studies.

CONCLUSIONS

Thickness profiles of individual grafts were fairly regular within the optically relevant area. A strong relationship between pre- and postoperative graft thicknesses was detected, and ultrathin DSAEK grafts prepared using methods similar to that applied in this study are expected to show a deswelling of around 12% during the first postoperative year. No correlation was detected between graft thickness and BSCVA.

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.

Graft Survival, Graft Rejection, and Glaucoma in a Consecutive Series of Descemet Stripping Endothelial Keratoplasty

PURPOSE

The goal of this study was to compare outcomes of Descemet stripping endothelial keratoplasty (DSEK) in eyes with glaucoma and abnormal anatomy to eyes with Fuchs endothelial corneal dystrophy (FECD).

METHODS

In a retrospective interventional series of all cases of DSEK between April 1, 2006, and November 30, 2015, recipient diagnosis, preoperative glaucoma status, concurrent surgical procedures, and graft outcomes were recorded. Graft survival, risk of rejection, and subsequent glaucoma surgery were estimated by using Kaplan-Meier analysis with risk factors determined by proportional hazard models.

RESULTS

Of 703 DSEKs in 666 eyes (509 subjects), the main recipient diagnoses were FECD (n = 496), pseudophakic corneal edema (n = 112), and failed graft (n = 83). Glaucoma was present in 150 cases before DSEK. Overall graft survival was 85%, 75%, and 71% at 5, 10, and 12 years, respectively, and for FECD without glaucoma was 95%, 89%, and 87% at 5, 10, and 12 years, respectively. Independent risk factors for graft failure included recipient diagnoses of pseudophakic corneal edema (HR = 8.3, P < 0.001), failed graft (HR = 6.4, P < 0.001), and preoperative medical glaucoma (HR = 7.1, P < 0.001) or surgical glaucoma (HR = 12.3, P < 0.001). Preoperative glaucoma treated by previous surgery resulted in graft survival of 28% at 10 years. Preoperative glaucoma was associated with an increased risk of graft rejection (HR = 6.8, P < 0.001) and subsequent glaucoma surgery (HR > 17.4, P < 0.001).

CONCLUSIONS

Preoperative glaucoma increases the risk of graft failure, graft rejection, and needing subsequent glaucoma surgery in the first decade after DSEK. With previous glaucoma surgery, DSEK graft survival was more favorable compared with published reports of Descemet membrane endothelial keratoplasty.

Design and Conduct of Randomized Clinical Trials Evaluating Surgical Innovations in Ophthalmology: A Systematic Review

PURPOSE

Surgical innovations are necessary to improve patient care. After an initial exploratory phase, novel surgical technique should be compared with alternative options or standard care in randomized controlled trials (RCTs). However, surgical RCTs have unique methodological challenges. Our study sought to investigate key aspects of the design, conduct, and reporting of RCTs of novel surgeries.

DESIGN

Systematic review.

METHODS

The protocol was prospectively registered in PROSPERO (CRD42021253297). RCTs evaluating novel surgeries for cataract, vitreoretinal, glaucoma, and corneal diseases were included. Medline, EMBASE, Cochrane Library, and Clinicaltrials.gov were searched. The search period was January 1, 2016, to June 16, 2021.

RESULTS

A total of 52 ophthalmic surgery RCTs were identified in the fields of glaucoma (n = 12), vitreoretinal surgery (n = 5), cataract (n = 19), and cornea (n = 16). A description defining the surgeon's experience or level of expertise was reported in 30 RCTs (57%) and was presented in both control and intervention groups in 11 (21%). Specification of the number of cases performed in the particular surgical innovation being assessed prior to the trial was reported in 10 RCTs (19%) and an evaluation of quality of the surgical intervention in 7 (13%). Prospective trial registration was recorded in 12 RCTs (23%) and retrospective registration in 13 (25%); and there was no registration record in the remaining 28 (53%) studies.

CONCLUSIONS

Important aspects of the study design such as the surgical learning curve, surgeon's previous experience, quality assurance, and trial registration details were often missing in novel ophthalmic surgical procedures. The Idea, Development, Exploration, Assessment, Long-term follow-up (IDEAL) framework aims to improve the quality of study design.

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.

Outcomes of the advanced visualization in corneal surgery evaluation trial; a non-inferiority randomized control trial to evaluate the use of intraoperative OCT during Descemet membrane endothelial keratoplasty

Objective

To evaluate if an intraoperative-OCT (iOCT) optimized surgical protocol without prolonged overpressure is non-inferior to a standard protocol during Descemet membrane endothelial keratoplasty (DMEK).

Methods

Sixty-five pseudophakic eyes of 65 patients with Fuchs endothelial dystrophy scheduled for routine DMEK were recruited in this prospective non-inferiority international multicenter randomized control trial. Subjects were randomized to the control arm (n=33) without iOCT-use and raising the intraocular pressure above normal physiological limits for 8 minutes (i.e., overpressure) or the intervention arm (n=32) with OCT-guidance to assess graft orientation and adherence, while refraining from prolonged overpressure. The primary outcome was the incidence of postoperative surgery-related adverse events (AE). The non-inferiority margin was set at a risk difference of 10%. Secondary outcomes included iOCT-aided surgical decision making, surgical times, and endothelial cell density (ECD) corrected distance visual acuity (CDVA) at 6 months follow-up.

Results

In the intervention group, 12 subjects developed 13 AEs compared to 13 AEs in 10 subjects in the control group (P=0.644). The risk difference measured -0.32% (95%CI: -10.29 - 9.84). The ECD and CDVA did not differ between the two groups 3 and 6 months postoperatively (P=>0.05). Surgeons reported that iOCT aided surgical decision-making in 40% of cases. Surgery and graft unfolding time were, respectively, 13% and 27% shorter in the iOCT-group.

Conclusions

iOCT-guided DMEK surgery with refraining from prolonged over-pressuring was non-inferior compared to conventional treatment. Surgery times were reduced considerably and iOCT aided surgical decision-making in 40% of cases. Refraining from prolonged overpressure did not affect postoperative ECD or CDVA.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT03763721 (NCT03763721).

Systematic Review and Meta-analysis: Outcomes After Descemet Membrane Endothelial Keratoplasty Versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty

PURPOSE

To compare the efficacy and safety of ultrathin Descemet stripping (automated) endothelial keratoplasty (UT-DS(A)EK) versus Descemet membrane endothelial keratoplasty (DMEK) for the treatment of Fuchs endothelial dystrophy (FED) and bullous keratopathy (BK).

DESIGN

Systematic review and meta-analysis.

METHODS

Literature containing DMEK and UT-DSAEK were searched in the Cochrane Database of Systematic Reviews, PubMed, EMBASE, LILACS, and through manual reference searching. Studies were included that measured the outcome of interventions-including best corrected visual acuity (BCVA), endothelial cell density (ECD), and postoperative complications, especially graft detachment with the need of re-bubbling, graft rejection, graft failure, and postoperative elevated intraocular pressure (IOP)-in patients with FED and BK. Included outcomes were pooled as standardized mean differences (SMD) or risk ratios (RR) using random effects models. Inter-study heterogeneity was assessed using the Q-test and I2 statistic.

RESULTS

Seven (of 163) studies met all the inclusion and exclusion criteria. Meta-analysis showed a significantly better BCVA 12 months postoperatively, but an increased re-bubbling rate in eyes after DMEK compared with eyes after UT-DS(A)EK (BCVA: SMD = 0.50 [95% CI 0.27-0.74] and re-bubbling rate: RR = 0.33 [95% CI 0.16-0.67]). All other parameters did not differ significantly between both interventions, although estimates were imprecise (graft failure: RR = 0.65 [95% CI 0.18-2.30], graft rejection: RR = 1.40 [95% CI 0.27-7.30], and postoperative intraocular pressure elevation: RR = 1.14 [95% CI 0.60-2.18]). Postoperative SMDs of ECD could not be evaluated due to significant heterogeneity between studies.

CONCLUSIONS

Although the improvement in BCVA was higher after UT-DS(A)EK than after conventional DS(A)EK, the BCVA after DMEK was still superior. The complication rates were comparable for both procedures, except for the higher rate of re-bubbling after DMEK.

Effect of Covid-19 on Eye Banks and Corneal Transplantations: Current Perspectives

The coronavirus disease 2019 (COVID-19) pandemic exerted a great impact on medical practice, which was reframed according to the actual needs. Ophthalmological services and procedures including corneal transplantation did not represent an exception. The adoption and implementation of new standard operating procedures as well as of new technologies for remote consultation and smart-working reshaped daily activities of both eye bankers, physicians, researchers, and patients. Regulatory restrictions were issued redefining corneal donor eligibility criteria, as well as handling and harvesting procedures of donor ocular tissues. Surgical schedules underwent an abrupt contraction with prioritization of urgent procedures. Local lockdowns and confinement strategies resulted in both a reduction and redirection of research activities. The evaluation of SARS-CoV-2 colonization of ocular tissues, long-term corneal storage techniques, new disinfection strategies, split corneal transplants and cell-based therapies for the treatment of corneal disease peaked in the pipeline. Aim of this article is to summarizes the overall impact of the pandemic on the corneal transplantation machinery, and the current and future perspectives for the corneal transplant community.

Results of ultrathin Descemet stripping automated endothelial keratoplasty with donor corneas preserved in synthetic organ culture media

PURPOSE

To evaluate outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) with donor corneas preserved at 31°C in Cornea Syn®, a medium formulated with recombinant human serum albumin (rHSA) to replace foetal calf serum, and deswelled-transported in the xeno-free medium Cornea Trans®.

METHODS

Prospective, multicentre, open-label study. We evaluated the endothelial cell loss (ECL) as the percentage variation of the endothelial cell density (ECD, cells/mm2) between 6 and 12 months after surgery, corneal transparency and thickness at 12 months, and adverse events within 12 months. Endothelial lenticules of mean 89 μm, ECD ≥ 2300 cells/mm2, minimum signs of cell mortality or morphology alterations, were dissected by microkeratome in the eye bank, and grafted in patients ≥ 18 years without corneal neovascularisation, conjunctivalization, or blinking impairment.

RESULTS

Thirty-five patients underwent UT-DSAEK, 3 showed primary failure, 1 late failure, and 2 skipped the 6-month visit. We analysed data from 29 patients, 27 with Fuchs endothelial corneal dystrophy (FECD) and 2 with pseudophakic bullous keratopathy (PBK). The median ECL between 6 and 12 months was 2.6% (p = .054, CI 0 to 12.5) and the absolute mean (SD) was 158.4 (364.1) cells/mm2. After 12 months, 96.5% of corneas were clear, with mean pachymetry of 585.9 (50.4) µm.

CONCLUSIONS

The ECL rate after UT-DSAEK match overall that observed in DSAEK or UT-DSAEK models of endothelial survival and the overall safety compared that reported for similar follow-up. Corneas maintained in Cornea Syn® and Cornea Trans® did not affect the ECD and functional outcomes of UT-DSAEK up to 12 months.

Graft Thickness at 6 Months Postoperatively Predicts Long-Term Visual Acuity Outcomes of Descemet Stripping Automated Endothelial Keratoplasty for Fuchs Dystrophy and Moderate Phakic Bullous Keratopathy: A Cohort Study

PURPOSE

It remains unclear whether preoperative central graft thickness (CGT) contributes to visual outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK). This retrospective cohort study examined the ability of preoperative and postoperative CGT to predict 12-month best spectacle-corrected visual acuity (BSCVA) after DSAEK for Fuchs endothelial corneal dystrophy/moderate pseudophakic bullous keratopathy/second graft.

METHODS

All consecutive patients who underwent DSAEK in 2015 to 2018 were included. The primary end point was 12-month BSCVA. DSAEK-CGT was measured preoperatively and 6 times between postoperative day 8 and month 12. Eyes were divided according to preoperative CGT 130 μm (ultrathin-DSAEK threshold) or 6-month postoperative CGT 100 μm (mean 6-month postoperative DSAEK-CGT). The t test assessed CGT evolution of the 4 groups over time. Multivariate analyses examined whether preoperative CGT or 6-month CGT categories predicted 12-month BSCVA. Multivariate analysis assessed the preoperative/perioperative factors that predicted 6-month CGT.

RESULTS

A total of 108 eyes (68 patients) underwent DSAEK. Preoperative CGT was >130 and ≤130 μm in 87 and 21 eyes, respectively. Postoperative CGT was >100 and ≤100 μm in 50 and 58 eyes, respectively. Thin 6-month postoperative grafts thinned significantly more relative to preoperative thickness than thick grafts ( P < 0.001). Preoperative CGT subgroups did not show this difference. Six-month postoperative CGT ( P = 0.01), but not preoperative CGT, predicted 12-month BSCVA. Preoperative CGT strongly predicted 6-month CGT ( P = 0.0003).

CONCLUSIONS

Postoperative, but not preoperative, DSAEK-CGT predicted 6-month BSCVA. The correlation between preoperative and postoperative CGT and interstudy variation in preoperative CGT measurement accuracy may explain literature disparities regarding the importance of preoperative CGT in DSAEK outcomes.

A machine learning approach to explore predictors of graft detachment following posterior lamellar keratoplasty: a nationwide registry study

Machine learning can be used to explore the complex multifactorial patterns underlying postsurgical graft detachment after endothelial corneal transplantation surgery and to evaluate the marginal effect of various practice pattern modulations. We included all posterior lamellar keratoplasty procedures recorded in the Dutch Cornea Transplant Registry from 2015 through 2018 and collected the center-specific practice patterns using a questionnaire. All available data regarding the donor, recipient, surgery, and practice pattern, were coded into 91 factors that might be associated with the occurrence of a graft detachment. In this research, we used three machine learning methods; a regularized logistic regression (lasso), classification tree analysis (CTA), and random forest classification (RFC), to select the most predictive subset of variables for graft detachment. A total of 3647 transplants were included in our analysis and the overall prevalence of graft detachment was 9.9%. In an independent test set the area under the curve for the lasso, CTA, and RFC was 0.70, 0.65, and 0.72, respectively. Identified risk factors included: a Descemet membrane endothelial keratoplasty procedure, prior graft failure, and the use of sulfur hexafluoride gas. Factors with a reduced risk included: performing combined procedures, using pre-cut donor tissue, and a pre-operative laser iridotomy. These results can help surgeons to review their practice patterns and generate hypotheses for empirical research regarding the origins of graft detachments.

Advances in eye banking and corneal tissue processing

PURPOSE OF REVIEW

Eye bank processing of donor corneal tissue has helped to revolutionize and popularize newer corneal transplantation surgeries. In particular, Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) have benefited from eye banks preparing donor corneal tissue in advance of the surgery. As a result of these eye banking advances, surgeons have been able to rapidly adopt these new techniques.

RECENT FINDINGS

This article reviews the techniques that are now being utilized to prepare donor tissue for endothelial keratoplasty (EK) with a focus on Ultrathin-DSAEK, prestamped, prestained, preloaded DMEK tissue, and advancements to improve the safety of donor corneal tissue.

SUMMARY

Collaborative efforts between surgeons and eye banks have been at the core of advances that have been made in EK over the past decade. Corneal surgery starts in the eye bank, and it is important for corneal surgeons to understand the process and appreciate the efforts that have been made to provide them with suitable and safe donor corneal tissue.

Graft Size and Double Scroll Formation Rate in Descemet Membrane Endothelial Keratoplasty

PURPOSE

This study aimed to evaluate the usefulness of intentional double scroll formation of donor Descemet membrane (DM) inside a glass tube inserter (the Fogla technique) in DM endothelial keratoplasty (DMEK) for controlled insertion and unfolding of grafts.

METHODS

Eleven consecutive patients who underwent DMEK were included in this study. We sought to specify graft characteristics in which double scroll configuration was successfully formed using the Fogla technique. We compared donor age, graft size, surgical time, unfolding time, and visual outcomes between patients with and without double scroll configuration. The ability to form double scroll formation of DM grafts of various diameters and unfolding time of DM grafts was evaluated using total seven eye-bank eyes in ex vivo experiments.

RESULTS

A double scroll configuration inside a glass tube was successfully obtained in six DMEK grafts (54.5%). When comparing clinical features between those with and without double scroll configuration, only graft size was significantly larger in those with double scroll configuration (7.9 ± 0.2 mm) than in those without (7.4 ± 0.4, P = 0.03). There were no significant differences in other features and clinical outcomes, although unfolding-time was shorter in eyes with double scroll configuration (4.6 ± 2.0 min) compared to those without (8.6 ± 8.1, P = 0.21). Ex vivo experiments showed that unfolding time was significantly shorter in double scroll configuration (2.71 ± 0.49 min) than in single scroll (5.02 ± 0.79, P = 0.01).

CONCLUSIONS

A double scroll configuration within a glass tube can be obtained more frequently in larger DMEK grafts (8.0 mm in diameter), which may result in easier and faster DMEK procedures.

Descemet membrane endothelial keratoplasty in complex eyes

PURPOSE OF REVIEW

To review the current literature on Descemet membrane endothelial keratoplasty (DMEK) in complex eyes.

RECENT FINDINGS

DMEK surgery has become a standardized procedure in Fuchs endothelial dystrophy and simple bullous keratopathy. But eyes with more complex disease present unique intraoperative and postoperative challenges to the DMEK surgeon. Poor visualization during surgery, complex anterior segment anatomy, altered anterior chamber dynamics, glaucoma shunts, and congenital or iatrogenic missing or altered iris and lens make DMEK surgery extremely difficult to accomplish.

SUMMARY

DMEK is feasible in complex eyes, including advanced bullous keratopathy, eyes with history of glaucoma or vitreoretinal surgery, previous penetrating keratoplasty, uveitis, pediatric, and congenital anterior segment disorders. The tools and methods reported in the literature to accomplish DMEK in complex eyes vary widely with no particular consensus or standardization of techniques. The outcomes noted for some of these conditions demonstrate the difficulty of the surgery and the uncertainty of long-term graft survival in complex eyes. Both surgical standardization and randomized prospective data will better help elucidate DMEK's role in the corneal rehabilitation of complex eyes.

“Endothelium-Out” and “Endothelium-In” Descemet Membrane Endothelial Keratoplasty (DMEK) Graft Insertion Techniques: A Systematic Review With Meta-Analysis

Background

We evaluated the visual outcomes and complications of “endothelium-out” and “endothelium-in” Descemet membrane endothelial keratoplasty (DMEK) graft insertion techniques.

Materials and Methods

Electronic searches were conducted in CENTRAL, Cochrane databases, PubMed, EMBASE, ClinicalTrials.gov. Study designs included clinical trials, comparative observational studies, and large case series (≥25 eyes). PRISMA guidelines were used for abstracting data and synthesis. Random-effects models were employed for meta-analyses.

Results

21,323 eyes (95 studies) were included. Eighty-six studies reported on “endothelium-out” techniques; eight studies reported on “endothelium-in” techniques. One study compared “endothelium-out” to “endothelium-in” techniques. Eighteen “endothelium-out” studies reported that 42.5–85% of eyes achieved best-corrected visual acuity (BCVA) ≥20/25 at 6 months; pooled proportion of eyes achieving BCVA ≥20/25 at 6 months was 58.7% (95% CI 49.4–67.7%,15 studies). Three “endothelium-in” studies reported that 44.7–87.5% of eyes achieved BCVA of ≥20/25 at 6 months; pooled proportion of eyes achieving BCVA ≥20/25 at 6 months was 62.4% (95% CI 33.9–86.9%). Pooled mean endothelial cell loss was lower in the “endothelium-in” studies (28.1 ± 1.3%, 7 studies) compared to “endothelium-out” studies (36.3 ± 6.9%,10 studies) at 6 months (p = 0.018). Graft re-bubbling rates were higher in the “endothelium-out” studies (26.2%, 95% CI 21.9–30.9%, 74 studies) compared to “endothelium-in” studies (16.5%, 95% CI 8.5–26.4%, 6 studies), although statistical significance was not reached (p = 0.440). Primary graft failure rates were comparable between the two groups (p = 0.552). Quality of evidence was considered low and significant heterogeneity existed amongst the studies.

Conclusion

Reported rates of endothelial cell loss were lower in “endothelium-in” DMEK studies at 6 months compared to “endothelium-out” studies. Outcomes of “endothelium-in” techniques were otherwise comparable to those reported in “endothelium-out” studies. Given the technical challenges encountered in “endothelium-out” procedures, surgeons may consider “endothelium-in” techniques designed for easier intra-operative DMEK graft unfolding. “Endothelium-in” studies evaluating outcomes at longer time points are required before conclusive comparisons between the two techniques can be drawn.

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.

Evolution of corneal transplantation techniques and their indications in a French corneal transplant unit in 2000–2020

Purpose

This retrospective cohort study assessed the evolution of corneal transplantation and its indications in the last 21 years (2000–2020) in a specialized ophthalmology department in a tertiary referral center in France.

Methods

The surgical techniques and indications, patient age and sex, and postoperative best-corrected visual acuity (BCVA) 6 months after keratoplasty were extracted.

Results

In total, 1042 eyes underwent keratoplasty in 2000–2020. Annual numbers of corneal transplantations increased by 2.2-fold. Penetrating keratoplasty (PKP) was the sole technique for the first 11 years. Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) were introduced in 2011 and 2014, respectively. Cases of both quickly increased, accounting for 28% and 41% of cases in 2015–2020, respectively. Eventually, DSAEK and DMEK were respectively used for most pseudophakic bullous keratopathy (PBK) and all Fuchs endothelial cell dystrophy (FECD) cases. PKP cases declined to 27%. Deep anterior lamellar keratoplasty (DALK) was rare (3% of all cases). These changes associated with rises in PBK and particularly FECD cases, and a strong decline in keratoconus, causing FECD, PBK, and keratoconus to move from being the 4^th, 1^st, and 3^rd most common indications to the 1^st, 2^nd, and 6^th, respectively. On average, BCVA improved by 0.1–0.3 logMAR. Patient age dropped steadily over time. Female predominance was observed.

Conclusions

The invention of DSAEK and then DMEK precipitated an enormous change in clinical practice and a large expansion of keratoplasty to new indications. This study confirms and extends previous findings in other countries.

Corneal Oedema: Aetiology, Diagnostic Testing, and Treatment

Corneal oedema results from an underlying pathology, which can be diverse in origin, and may be mechanical, dystrophic, or inflammatory, and affect any layer of the cornea. Diagnostic tools such as Scheimpflug imaging and anterior segment optical coherence tomography have standardised quantification of corneal oedema and have become important aids in clinical practice. Timely diagnosis and treatment are key to preventing irreversible damage to the corneal ultrastructure, such as anterior corneal fibrosis or endothelial cell damage. The oedema usually resolves quickly when the underlying cause has been addressed. Symptomatic treatment using hyperosmolar agents has failed to show any benefits in oedema resolution or improvement in visual acuity compared to placebo. In contrast, rho-associated protein kinase (ROCK) inhibitors offer a promising option for medical treatment in cases of endothelial dysfunction, but their safety and efficacy must be further validated in large scale clinical trials. Until then, endothelial or penetrating keratoplasties remain the mainstay treatment where structural changes to the cornea have occurred.

Efficacy of Thin and Ultrathin Descemet Stripping Automated Endothelial Keratoplasty and Influence of Graft Thickness on Postoperative Outcomes: Systematic Review and Meta-analysis

PURPOSE

To conduct a systematic review and meta-analysis on the efficacy of thin and ultrathin Descemet stripping automated endothelial keratoplasty (T-DSAEK and UT-DSAEK, with graft thickness <130 and <100 µm, respectively), depending on graft thickness.

DESIGN

Systematic review and meta-analysis.

METHOD

PubMed, Cochrane Library, Embase, ClinicalTrials.gov, and ScienceDirect databases were searched until October 1, 2021. We computed random-effect meta-analysis on postoperative outcomes of T/UT-DSAEK, stratified by graft thickness (<80 μm, 80-100 μm, and 100-130 μm). The main postoperative outcome was visual acuity (logarithm of the minimum angle of resolution [logMAR]). Secondary outcomes were pachymetry (μm), endothelial cell count (cell/mm²), spherical equivalent (diopter [D]), rebubbling rate (%), and rejection rate (%). Meta-regressions compared postoperative outcomes depending on graft thickness and search for putative confusion factors.

RESULTS

We included 47 articles for a total of 2141 eyes of 2040 patients. T/UT-DSAEK globally improved visual acuity (effect size = -0.38 logMAR [95% confidence interval {CI} -0.46 to -0.30 logMAR]), without difference depending on graft thickness. Overall, pachymetry improved (-60.6 µm [95% CI -101 to -19.7 µm]), endothelial cell count decreased (-1039 cells/mm² [95% CI -1209 to -868 cells/mm²), spherical equivalent resulted in a hyperopic shift (0.74 D [95% CI -0.50 to 1.97 D), the graft rejection rate was 0.2% (95% CI -0.1% to 0.4%), and the rebubbling rate was 8.7% (95% CI 6.8%-10.5%). Grafts >100 μm induced a hyperopic shift. Metaregressions did not demonstrate differences between the 3 groups (<80 μm, 80-100 μm, or 100-130 μm) in any outcomes.

CONCLUSION

All T/UT-DSAEK thickness groups provided similar visual acuity, pachymetry, endothelial cell count, rejection rate, and rebubbling rate regardless of graft thickness. A hyperopic shift was induced by grafts >100 μm.

Intraoperative optical coherence tomography-guided nanothin Descemet stripping automated endothelial keratoplasty in a patient with a remarkably thickened cornea

Purpose

To report use of intraoperative optical coherence tomography (OCT) for nanothin Descemet stripping automated endothelial keratoplasty (DSAEK) in a patient with an extremely thickened cornea due to advanced bullous keratopathy.

Observations

A 90-year-old woman with a history of multiple trabeculectomies was referred to us for treatment of advanced bullous keratopathy (1400 μm central corneal thickness). Nanothin DSAEK was planned and performed. In brief, after the removal of the loose corneal epithelium, the anterior chamber was meticulously observed using a surgical microscope and oblique light via an endoillumination probe; however, the visibility of the anterior chamber was limited because of severe corneal edema. Subsequently, a nanothin (47 μm) DSAEK graft stained with trypan blue was inserted into the anterior chamber using an NS endoinserter. Intraoperative OCT was used successfully to visualize the graft unfolding, air tamponade, and graft attachment. At 3 months postoperatively, significant corneal clearing (625 μm central corneal thickness), improvement of visual acuity (decimal 0.04), and pain relief were obtained.

Conclusions and importance

Intraoperative OCT is useful for nanothin DSAEK even when the surgical microscope view is compromised by a remarkably thickened host cornea due to advanced bullous keratopathy. As an alternative to a penetrating keratoplasty, less invasive nanothin DSAEK was successfully performed.

Identification of the preoperative and perioperative factors that predict postoperative endothelial cell density after Descemet membrane endothelial keratoplasty: A retrospective cohort study

Low postoperative endothelial-cell density (ECD) plays a key role in graft failure after Descemet-membrane endothelial keratoplasty (DMEK). Identifying pre/perioperative factors that predict postoperative ECD could help improve DMEK outcomes. This retrospective study was conducted with consecutive adult patients with Fuchs-endothelial corneal dystrophy who underwent DMEK in 2015–2019 and were followed for 12 months. Patients underwent concomitant cataract surgery (triple-DMEK) or had previously undergone cataract surgery (pseudophakic-DMEK). Multivariate analyses assessed whether: patient age/sex; graft-donor age; preoperative ECD, mean keratometry, or visual acuity; triple DMEK; surgery duration; surgical difficulties; and need for rebubbling predicted 6- or 12-month ECD in the whole cohort or in subgroups with high/low ECD at 6 or 12 months. The subgroups were generated with the clinically relevant threshold of 1000 cells/mm². Surgeries were defined as difficult if any part was not standard. In total, 103 eyes (95 patients; average age, 71 years; 62% women) were included. Eighteen eyes involved difficult surgery (14 difficult graft preparation or unfolding cases and four others). Regardless of how the study group was defined, the only pre/perioperative variable that associated significantly with 6- and 12-month ECD was difficult surgery (p = 0.01, 0.02, 0.05, and 0.0009). Difficult surgery also associated with longer surgery duration (p = 0.002). Difficult-surgery subgroup analysis showed that difficult graft dissection associated with lower postoperative ECD (p = 0.03). This association may reflect endothelial cell loss due to excessive graft handling and/or an intrinsic unhealthiness of the endothelial cells in the graft that conferred unwanted physical properties onto the graft that complicated its preparation/unfolding.

Long-term Outcomes in Fellow Eyes Comparing DSAEK and DMEK for Treatment of Fuchs Corneal Dystrophy

PURPOSE

To compare the long-term results of Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK) in fellow eyes for treatment of Fuchs endothelial corneal dystrophy.

METHODS

This study is a 2-centered, retrospective case series of 64 patients (128 eyes) with DSAEK followed by DMEK. The main outcomes measured were best spectacle-corrected visual acuity (BSCVA) and duration of time to achieve BSCVA as well as eye preference.

RESULTS

Preoperative median logarithm of the minimum angle of resolution (logMAR) BSCVA was similar in eyes receiving DMEK 0.36 ± 0.26 and DSAEK 0.42 ± 0.34 (P = .266). The average follow-up time needed for the DMEK eyes to achieve BSCVA was faster than that of DSAEK (277 days vs 490 days, P = .0014). With long-term follow-up, the BSCVA of the DMEK eyes [0.09 ± 0.10 logMAR] and DSAEK eyes [0.11 ± 0.16 logMAR] did not show a statistically significant difference (P = .069). Twenty-two of the 64 preferred the DMEK eye, 17 patients preferred the DSAEK eye (P = .423), and 25 patients did not have a preference. In the DMEK group, the average spherical equivalent was -0.08 compared with the DSAEK group at 0.06 (P = .2854).

CONCLUSION

In our fellow eye study with long-term follow-up, DMEK and DSAEK had comparable levels of BSCVA and patient satisfaction. The DMEK eyes reached their BSCVA sooner, whereas the DSAEK eyes improved over a longer time frame. A greater number of patients had 20/25 and 20/20 vision in the DMEK group; however, the difference was not statistically significant. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Quality of vision and vision-related quality of life after Descemet membrane endothelial keratoplasty: a randomized clinical trial

Purpose

To compare quality of vision and vision‐related quality of life (QOL) in patients undergoing Descemet membrane endothelial keratoplasty (DMEK) or ultrathin Descemet stripping automated endothelial keratoplasty (DSAEK).

Methods

Fifty‐four eyes of 54 patients with Fuchs' dystrophy from six corneal clinics in the Netherlands were randomized to DMEK or ultrathin DSAEK and examined preoperatively, and 3, 6 and 12 months postoperatively. Main outcome measures were corneal higher‐order aberrations (HOAs), contrast sensitivity, straylight and vision‐related QOL.

Results

Posterior corneal HOAs decreased after DMEK and increased after ultrathin DSAEK (p ≤ 0.001) 3 months after surgery and correlated positively with best spectacle‐corrected visual acuity (12 months: r = 0.29, p = 0.04). Anterior and total corneal HOAs did not differ significantly between both techniques at any time point. Contrast sensitivity was better (p = 0.01), and straylight was lower (p = 0.01) 3 months after DMEK compared with ultrathin DSAEK; 95% confidence interval [CI] of log(cs) 1.10–1.35 versus 95% CI: 0.84 to 1.12, and 95% CI: log(s) 1.18 to 1.43 versus 95% CI: 1.41 to 1.66, respectively. Both were comparable at later time points. Vision‐related QOL (scale 0–100) did not differ significantly between both groups at any time point and improved significantly at 3 months (β = 12 [95% CI: 7 to 16]; p < 0.001), and subsequently between 3 and 12 months (β = 5 [95% CI: 0 to 9]; p = 0.06).

Conclusions

Descemet membrane endothelial keratoplasty (DMEK) results in lower posterior corneal HOAs compared with ultrathin DSAEK. Contrast sensitivity and straylight recover faster after DMEK but reach similar levels with both techniques at 1 year. Vision‐related QOL improved significantly after surgery, but did not differ between both techniques.

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 (β = −0.49, p = 0.002), 3-month (β = −0.50, p < 0.001), 6-month (β = −0.58, p < 0.001) and 12-month (β = −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.

Comparison of DMEK and DSAEK in Eyes With Endothelial Decompensation After Previous Penetrating Keratoplasty

PURPOSE

Posterior lamellar keratoplasty is increasingly applied in patients with endothelial decompensation after penetrating keratoplasty (PK). The aim of this study was to compare the results of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) after PK.

METHODS

In this retrospective study, clinical data of 30 patients who received DMEK (n = 19) or DSAEK (n = 11) for endothelial decompensation after PK were evaluated. All lamellar keratoplasties were performed at the Department of Ophthalmology at University Hospital Mainz, Germany. Primary end point included best-corrected visual acuity, and secondary end points included endothelial cell density, rebubbling, and rejection rates, all at 6 and 12 months.

RESULTS

After 6 months and 12 months, 89% of DMEK and 73% of DSAEK grafts and 63% of DMEK and 64% of DSAEK grafts provided sufficient corneal deturgescence, respectively, represented by improvement in best-corrected visual acuity. DMEK group median preoperative Logarithm of the Minimum Angle of Resolution visual acuity of 1 increased to 0.5 after 6 and 12 months. DSAEK group median Logarithm of the Minimum Angle of Resolution visual acuity increased from 3 to 2 and 1.3 after 6 and 12 months. After 12 months, graft endothelial cell density had decreased by 58% in the DMEK group and by 59% in the DSAEK group. The proportion of patients requiring a rebubbling were 63% in the DMEK and 64% in the DSAEK group. No lamellar graft rejection occurred in either trial arm.

CONCLUSIONS

Both DMEK and DSAEK significantly improved visual acuity in patients after PK. Lamellar graft survival, loss of endothelial cells, and mean rebubbling rates were similar in both groups.

Microthin Descemet Stripping Automated Endothelial Keratoplasty Versus Descemet Membrane Endothelial Keratoplasty: A Randomized Clinical Trial

PURPOSE

To compare visual outcomes, complications, and vision-related quality of life (QoL) after microthin Descemet stripping automated endothelial keratoplasty (MT-DSAEK) versus Descemet membrane endothelial keratoplasty (DMEK) for the management of corneal endothelial dysfunction in Fuchs dystrophy.

METHODS

This is a prospective, double-blinded randomized controlled clinical trial. Patients with visually significant endothelial decompensation from Fuchs dystrophy were prospectively randomized to receive MT-DSAEK or DMEK surgery. The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 12 months. Secondary outcomes included refraction, keratometry, endothelial cell count, complications, and vision-related QoL at 6 and 12 months postoperatively.

RESULTS

A total of 56 eyes of 56 patients were enrolled, 28 in each group. Postoperatively, LogMAR mean BSCVA in the MT-DSAEK group was 0.17 ± 0.08 and 0.11 ± 0.09 at 6 and 12 months compared with 0.09 ± 0.13 and 0.04 ± 0.13 after DMEK (P = 0.03, P = 0.002 respectively) with the DMEK cohort achieving 3.5 logarithm of the minimum angle of resolution letters better BSCVA at 1 year compared with MT-DSAEK. Complication rates were similar with 3.5% rebubbling rate in both groups, 1 primary graft failure in DMEK and a single endothelial rejection in the MT-DSAEK arm. Vision-related QoL was comparable at 6 and 12 months postoperatively, and no eyes demonstrated loss of vision from preoperative BSCVA.

CONCLUSIONS

DMEK surgery resulted in significantly better BSCVA at 1, 3, 6, and 12 months postoperatively compared with MT-DSAEK. Patient satisfaction was similar with no differences reported in vision-related QoL scores, as was the complications profile between groups. Thus, our results favor DMEK as the better choice procedure for eyes with Fuchs-related corneal decompensation without ocular comorbidities.