Five-Year Outcomes of Ultrathin Descemet Stripping Automated Endothelial Keratoplasty

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.

[Keratoplasty - an Overview of the Methods and their Perioperative Management]

Corneal transplantation can be divided into two groups: penetrating and lamellar keratoplasty. Newer minimally invasive procedures have emerged over the years, to improve the visual outcome and reduce complications. This article summarizes the different procedures, their indications and complications, and outlines the pre-, peri- and postoperative management in a clinical setting.Corneal transplantation is the most commonly performed transplantation of donor tissue in modern medicine. In the last years a shift away from penetrating keratoplasty (PK) towards minimally invasive lamellar operative techniques, associated with less complications, can be observed. The Descemet membrane endothelial keratoplasty (DMEK) is used to treat endothelial corneal pathologies and has overtaken the PK to become the most commonly performed form of keratoplasty. Preparation and identification of possible risk-factors are essential preoperative steps to reduce peri- and postoperative complications of keratoplasties. If corneal graft rejection occurs, early and maximum therapy is crucial for graft survival. Laser-assisted techniques offer different advantages in lamellar and penetrating keratoplasty but are not very cost-efficient.

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.

Emerging treatments for corneal endothelium decompensation - a systematic review

PURPOSE

Endothelial keratoplasty (EK) is the conventional treatment to improve visual acuity of corneal endothelium decompensation (CED) patients, with other therapies mainly for symptomatic relief. However, the shortage of corneal grafts and other limitations to EK urge the development of novel alternative treatments. In the last decade, novel options have been proposed, yet only a limited number of reviews have systematically reported on outcomes. Therefore, this systematic review evaluates the existing clinical evidence of novel surgical approaches for CED.

METHOD

We identified 24 studies that illustrated the clinical observations of the surgical approaches in interest. We included Descemet stripping only (DSO), Descemet membrane transplantation (DMT) where Descement membrane alone instead of corneal endothelium with cells is transplanted, and cell-based therapy.

RESULTS

In general, these therapies may provide visual outcomes comparable with EK under specific conditions. DSO and DMT target CED with relatively healthy peripheral corneal endothelium like Fuchs' corneal endothelial dystrophy, while cell-based therapy offers more versatile applications. Side effects of DSO would decrease with modifications to surgical techniques. Moreover, Rho-associated protein kinase inhibitor adjuvant therapy could enhance clinical results in DSO and cell-based therapy.

CONCLUSION

Long-term controlled clinical trials with larger sample size on the therapies are needed. The simplicity of DSO and the high translational potential of cell-based therapy to treat CED of most etiologies made these two treatment strategies promising.

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.

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.

Long-term Outcomes After Lamellar Endothelial Keratoplasty Compared With Penetrating Keratoplasty for Corneal Endothelial Dysfunction: A Systematic Review

PURPOSE

The purpose of this study is to evaluate long-term outcomes of endothelial keratoplasty (EK) compared with penetrating keratoplasty (PK) for corneal endothelial dysfunction [Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK)].

METHODS

In this systematic review, we searched PubMed, the Cochrane Library, and Embase up to May 2022 and considered all types of studies addressing our objective. Graft survival at 5, 10, and 15 years was the main outcome.

RESULTS

Fifty cohort studies were included. At 5 years, in FECD and BK, graft survival seemed higher after EK than PK. Two comparative studies showed either a higher 5-year graft survival after EK than PK or no significant differences. Including noncomparative studies, in FECD, the 5-year graft survival ranged from 0.69 to 0.98 for PK, from 0.93 to 1.00 for DSEK, and from 0.93 to 0.99 for Descemet membrane endothelial keratoplasty (DMEK). In BK, the 5-year graft survival ranged from 0.39 to 0.91 for PK, from 0.65 to 0.89 for DSEK, and from 0.84 to 0.95 for DMEK. The 10-year graft survival ranged from 0.20 to 0.90 for PK and from 0.62 to 0.92 for EK. The mean 5-year best spectacle-corrected visual acuity ranged from 0.73 to 0.43 LogMAR for PK, from 0.61 to 0.09 for DSEK, and from 0.31 to 0.05 for DMEK. The 5-year rejection rate ranged from 11.0% to 28.7% for PK, from 5.0% to 7.9% for DSEK, and from 1.7% to 2.6% for DMEK.

CONCLUSIONS

These results suggest a higher 5-year graft survival and better secondary outcomes after EK. Nevertheless, the level of evidence was low.

PROSPERO REGISTRATION

CRD42021260614.

[Risk factors for failure of pre-cut eye bank UT-DSAEK grafts]

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.

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.

Changes in Corneal Power up to 2 Years After Endothelial Keratoplasty: Results From the Randomized Controlled Descemet Endothelial Thickness Comparison Trial

PURPOSE

To compare changes in corneal power measurements after Descemet membrane endothelial keratoplasty (DMEK) vs ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK).

DESIGN

Post hoc subanalysis of the randomized controlled Descemet Endothelial Thickness Comparison Trial.

METHODS

A total of 50 eyes (38 patients) with endothelial dysfunction from Fuchs' endothelial dystrophy or pseudophakic bullous keratopathy were randomized to DMEK or UT-DSAEK 1 to 2 days before surgery. Total corneal refractive power (TCRP) and anterior/posterior simulated keratometry were obtained using Scheimpflug imaging preoperatively (baseline) and postoperatively at 3, 6, 12, and 24 months. Spectacle refractions were performed at 6, 12, and 24 months after surgery.

SETTING

Hospital centers.

RESULTS

The mean hyperopic shift of TCRP from baseline to 12 months was 0.80 ± 1.1 (P = .002) in the DMEK group and 0.69 ± 0.84 (P < .001) in the UT-DSAEK group. Posterior corneal curvature (average K from simulated keratometry) steepened (more negative dioptric power) by 0.42 ± 0.10 (P < .001) in DMEK and 0.54 ± 0.09 (P < .001) in UT-DSAEK. The mean change in TCRP and posterior corneal curvature did not differ between DMEK and UT-DSAEK (TCRP, P = .71; posterior average K from simulated keratometry, P = .36).

CONCLUSIONS

Sustained steepening in posterior corneal curvature with loss in total corneal power contributes to hyperopic shifts after endothelial keratoplasty. Changes in corneal measurements do not differ between DMEK and UT-DSAEK. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

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.

Impact of vaccination on keratoplasty

PURPOSE OF REVIEW

Corneal graft rejection has been reported after coronavirus disease 2019 (COVID-19) vaccination. The purpose of this review is to evaluate the literature regarding corneal graft rejection after vaccination, including rejection rates and risk factors. We aim to create a framework to identify patients who are at higher risk for graft rejection and may warrant consideration of prophylactic interventions.

RECENT FINDINGS

Graft rejection has been reported following administration of mRNA, viral vector, and inactivated whole-virion COVID-19 vaccines. Most cases had additional risk factors associated with rejection. Vaccination increases circulation of proinflammatory cytokines, CD4+ and CD8+ T-cell responses, and antispike neutralizing antibody, all of which may contribute to graft rejection. Two prospective studies have found no relationship between recent vaccination and rejection but 20% of cornea specialists report to have seen a vaccine-associated rejection and 22% recommend delaying vaccination in certain circumstances. Many specialists recommend prophylactic topical corticosteroids before and after vaccination to mitigate rejection risk but there is no evidence to support this practice on a wider scale.

SUMMARY

Our framework identified 96.8% of penetrating keratoplasty patients with vaccine-associated rejection as higher risk. Further research is needed in order to develop evidence-based guidelines.

10-year experience with lamellar keratoplasty for the surgical Management of Paediatric Corneal Diseases

PURPOSE

To evaluate the outcomes of various lamellar keratoplasty techniques performed at our Institution in children aged 14 years or younger over the last decade.

METHODS

This single-centre study reviewed 72 eyes that underwent lamellar keratoplasty for various indications. Deep anterior lamellar keratoplasty (DALK) was performed in 19 eyes, mushroom penetrating keratoplasty (PK) in 27 eyes and Descemet stripping automated endothelial keratoplasty (DSAEK) in 25 eyes. The main outcome measures included best spectacle-corrected visual acuity (BSCVA), complications and rate of graft failure which was defined as any graft requiring repeat transplantation.

RESULTS

Best spectacle-corrected visual acuity (BSCVA) significantly improved after DALK, mushroom PK and DSAEK (all p < 0.05), with 50%, 60% and 56% of eyes reaching ≥20/40, respectively. Stromal rejection was observed in 1 eye (5.3%) after DALK, whilst endothelial rejection occurred in 1 eye after mushroom PK (3.7%) and 1 eye after DSAEK (4.0%). Overall survival was 100% after DALK (mean follow-up: 23.0 months), 92.8% after mushroom PK (mean follow-up: 42.3 months) and 96.0% after DSAEK (mean follow-up: 33.6 months).

CONCLUSION

Deep anterior lamellar keratoplasty (DALK), mushroom PK and DSAEK offer good visual outcomes for children with corneal pathology, with low rates of immunological rejection and graft failure.

Superiority of Mature Differentiated Cultured Human Corneal Endothelial Cell Injection Therapy for Corneal Endothelial Failure

PURPOSE

To investigate the safety and efficacy of cultured human corneal endothelial cell (hCEC) injection therapy with mature differentiated (mature) cell subpopulations (SPs) for corneal endothelial failure (CEF).

DESIGN

Comparative, interventional case series.

METHODS

This study involved 18 eyes with CEF that underwent cultured hCEC injection therapy, categorized into 2 groups: (1) 11 eyes administered a relatively lower proportion (0.1 to 76.3%) of mature cell SPs (group 1 [Gr1]), and (2) 7 eyes administered a relatively higher proportion (>90%) of mature cell SPs (group 2 [Gr2]). From 1 week to 3 years postoperation, corneal endothelial cell (CEC) density (CECD), central corneal thickness (CCT), and best-corrected visual acuity (BCVA) were recorded, and the CEC parameter's "spring constant" was calculated. The proportion of mature SPs was evaluated by fluorescence-activated cell sorting analysis based on cell-surface markers.

RESULTS

At 3 years postoperation, corneal restoration with improved BCVA was attained in 10 of the 11 Gr1 eyes and all Gr2 eyes, the median CECD in Gr2 (3083 cells/mm²; range, 2182-4417 cells/mm²) was higher than that in Gr1 (1349 cells/mm²; range, 746-2104 cells/mm²) (P < .001), and the spring constant verified the superiority of the mature cultured hCECs. From 24 weeks through 3 years postoperation, the median percentage of CECD decrease was 3.2% in Gr2 and 23.6% in Gr1 (P < .005). CCT recovery was prompt and constant in Gr2, while diverse in Gr1. No adverse events were observed.

CONCLUSION

Our findings showed that mature cell SPs for hCEC injection therapy provide rapid recovery of CCT, better CECD, and low CECD attrition over 3 years postsurgery.

Current Perspectives on Corneal Transplantation

Disease of the cornea is the third leading cause of blindness worldwide. Corneal graft surgery is one of the most successful forms of solid organ transplantations in humans, with ever-increasing developments in surgical technique. To date, approximately 4504 corneal transplants are performed in the United Kingdom each year. While full thickness transplantation was the most commonly performed keratoplasty over the last few decades, selective lamellar transplantation of the diseased layers of the cornea has been universally adopted. This comprehensive review aims to provide an updated synthesis on different types of corneal transplantations, their treatment outcomes, and the associated complications of each procedure in both adult and paediatric population. In addition, we also present an up-to-date summary of the emerging therapeutic approaches that have the potential to reduce the demand for donor-dependent keratoplasty.

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.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

BACKGROUND

We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles.

RESULTS

Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes.

CONCLUSIONS

Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

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.

Nomogram for single-pass automated microkeratome graft preparation for ultrathin Descemet stripping automated endothelial keratoplasty

PURPOSE

To create a nomogram including the translational speed of the microkeratome blade, microkeratome head size and precut tissue thickness to predict the postcut thickness for Descemet stripping automated endothelial keratoplasty to obtain the thinnest possible graft.

METHODS

This prospective study incorporated 48 grafts for DSAEK from March 2017 to June 2020. Corneal tissue for DSAEK was prepared by 3 experienced physicians using the Moria Evolution 3E (Moria Inc, Antony, France) microkeratome with 400, 450 and 500 μm head sizes. Precut central corneal thickness was measured with a DGH 550 handheld pachymeter (Pachette 2), taking an average of 3 readings. The microkeratome head was selected according to precut tissue thickness. The selected microkeratome head size was 150 μm less than the donor cornea thickness. Two translational speeds were used for the microkeratome cuts. One month after surgery, the central lenticular thickness was measured with a Visante® Optical Coherence Tomography caliper (Carl Zeiss Meditec Inc, Germany). A descriptive analysis was performed.

RESULTS

Forty-eight donor grafts were prepared. Mean graft thickness was 97.58 ± 29.84 μm (range 39-176 μm). Of the 48 samples, central graft thickness was < 120 µm (81.3%) in 39, < 100 µm (58.3%) in 28 and < 80 µm (37.5%) in 18 at 1-month follow-up. There were no statically significant differences between translational speeds.

CONCLUSIONS

A nomogram with an automated microkeratome to obtain thin grafts for DSAEK provided good graft thickness results without donor waste.

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.

Advances in corneal graft rejection

PURPOSE OF REVIEW

Immune rejection after corneal transplantation is a major risk for graft failure. We aim to summarize recent advances in the understanding and management of graft rejection.

RECENT FINDINGS

Immune rejection remains the leading cause of graft failure in penetrating keratoplasty (PKP). While ABO blood type and sex match between donor and recipient may reduce rejection, human leucocyte antigens class II matching in a randomized study did not reduce the risk of rejection in high-risk PKP. Compared with PKP, deep anterior lamellar keratoplasty, descemet stripping automated endothelial keratoplasty, and descemet membrane endothelial keratoplasty have lower immune rejection rates of 1.7-13%, 5-11.4%, and 1.7-2.8%, respectively, based on long-term (5 years and more) studies. Whether immune rejection is a major risk factor for graft failure in these lamellar keratoplasties is unclear. While there have not been major advances in the systemic management of graft rejection, topical nonsteroid agents such as tacrolimus and anti-vascular endothelial growth factor have shown promise in high-risk cases.

SUMMARY

Immune rejection remains the leading cause of graft failure in PKP. Lamellar keratoplasties have significantly lower rejection rates compared with PKP. The significance of rejection in the failure of lamellar grafts warrants further investigation.

Evaluation of Donor and Recipient Characteristics Involved in Descemet Stripping Automated Endothelial Keratoplasty Outcomes

Aims: To evaluate both donor and recipient features involved in visual acuity restoring and complication insurgence in eyes that have undergone Descemet stripping automated endothelial keratoplasty (DSAEK).

Methods: In this retrospective study, charts of 111 eyes of 96 patients (mean age 70.25 ± 8.58 years) that underwent DSAEK were evaluated. Only Fuch's Distrophy (FD) or Bullous Keratopathy (BK) due to cataract surgery eyes were included. A complete ophthalmic check with endothelial cell density (ECD) and central corneal thickness (CCT) measurement was performed before surgery and at 1, 3, 6, and 12 months follow-up. Each DSAEK was performed by the same well-trained surgeon; only pre-cut lenticules, provided by same Eye Bank, were implanted.

Results: A total of 48 (43%) complications have been observed (most of them were 22 partial graft detachments and 17 IOP spikes). At the last follow-up (mean: 8.58 ± 4.09 months), a significant increase (p < 0.05) of best corrected visual acuity (BCVA) was detected. Overall mean BCVA of the eyes evaluated was 0.40 ± 0.43 LogMAR with BK eyes showing a significantly higher improvement (p < 0.05) compared to FD eyes. The only factor showing a significant correlation (p < 0.05) with visual acuity enhancement was the implant of a lenticule thinner than 100 μm. Recipient features significantly (p < 0.05) associated with complications observed after surgery were glaucoma and diabetes mellitus.

Conclusion: The use of a graft thinner than 100 μm can provide better visual acuity recovery while recipients affected by glaucoma or diabetes mellitus are more prone to develop complications after surgery.

Bilateral Ultrathin Descemet's Stripping Automated Endothelial Keratoplasty vs. Bilateral Penetrating Keratoplasty in Fuchs' Dystrophy: Corneal Higher-Order Aberrations, Contrast Sensitivity and Quality of Life

Background and Objectives: The objective of this paper is to compare the visual outcomes and quality of life (QoL) after bilateral ultrathin Descemet's stripping automated endothelial keratoplasty (UT-DSAEK) with bilateral penetrating keratoplasty (PK) for Fuchs' endothelial dystrophy (FED). Materials and Methods: Retrospective comparative cohort study, including 11 patients with FED who underwent bilateral PK and 13 patients with FED who underwent bilateral UT-DSAEK. All patients were already pseudophakic or had undergone a combined cataract procedure. The main outcomes were corrected distance visual acuity (CDVA) corneal higher-order aberrations (HOAs), contrast sensitivity (CS) and quality of life (QoL). Results: The mean follow-up after the second eye surgery was 32.5 ± 10.2 months in PK and 19.6 ± 8.6 months in UT-DSAEK patients. The CDVA in the UT-DSAEK group was significantly better than in the PK one (0.18 ± 0.07 vs. 0.35 ± 0.16 logMAR, p < 0.0001). The mean anterior corneal total HOAs of the central 5 mm were significantly lower in UT-DSAEK eyes than in PK eyes (0.438 ± 0.078 µ and 1.282 ± 0.330 µ respectively, p < 0.0001), whilst the mean posterior total HOAs did not differ between groups (0.196 ± 0.056 µ and 0.231 ± 0.089 µ, respectively, p = 0.253). The CS was lower at 0.75 and 1.5 cycles/degree in P the K group when compared to the DSAEK one (p = 0.008 and 0.005, respectively). The QoL scores by the NEI RQL-42 test exhibited better values in DSAEK patients in 9 out of 13 scales. Conclusion: Our study confirms that UT-DSAEK provides a better visual function in terms of CDVA and CS, together with lower HOAs, when compared to PK. Hence, the vision-related QoL, binocularly evaluated by the NEI RQL-42 items, indicates a higher satisfaction in UT-DSAEK eyes.

[UT-DSAEK using grafts provided by a tissue bank, a one-year follow-up study of 79 grafts]

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.

Descemet Membrane Endothelial Keratoplasty Using a Pull-Through Technique With Novel Infusion Forceps

PURPOSE

To describe a surgical technique of Descemet membrane endothelial keratoplasty (DMEK) using an endothelium-in pull-through technique with novel infusion forceps and report 6-month clinical outcomes.

METHODS

This is a retrospective case series of 33 cases with Fuchs endothelial corneal dystrophy who underwent either DMEK alone (n = 5), DMEK combined with phacoemulsification (n = 27), or DMEK combined with intraocular lens exchange (n = 1) performed by surgeons at the beginning of the DMEK learning curve. Best-corrected visual acuity (BCVA), manifest refraction, central corneal thickness, endothelial cell density, intraoperative and postoperative complications, and need for additional surgeries including rebubbling were evaluated through 6 months postoperatively.

RESULTS

Preoperative BCVA was 0.37 ± 0.34 logarithm of the minimum angle of resolution and improved to 0.09 ± 0.10 logarithm of the minimum angle of resolution at 6 months (P < 0.001). Eighty-two percent of eyes obtained a BCVA of 20/25 or better. Central corneal thickness decreased significantly at 6 months (P < 0.001). Endothelial cell loss was 29.1% at 6 months (available for 20 of 33 eyes). All surgeries were uneventful. Six eyes required rebubbling for graft detachments. There were no primary or secondary graft failures at 6 months.

CONCLUSIONS

DMEK with infusion microforceps is efficacious and safe in eyes with Fuchs endothelial corneal dystrophy and could offer a more controlled surgery, making it suitable for both novice and experienced DMEK surgeons.

Three-Year Outcomes of Tri-Folded Endothelium-In Descemet Membrane Endothelial Keratoplasty With Pull-Through Technique

PURPOSE

To assess the 3-year outcomes of tri-folded endothelium-in Descemet membrane endothelial keratoplasty (DMEK) using bimanual pull-through delivery technique.

DESIGN

Interventional case series.

METHODS

In this single-center study, we included 153 consecutive eyes that underwent DMEK for various indications (Fuchs endothelial corneal dystrophy [FECD]: n = 111; bullous keratopathy [BK]: n = 24; and failed graft: n = 18). DMEK grafts were loaded into a disposable cartridge in a tri-folded, endothelium-in configuration and delivered using bimanual pull-through technique. Main outcome measures were graft preparation and unfolding times, best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), and graft survival.

RESULTS

Mean graft preparation time was 5.9 ± 1.1 minutes; and mean graft unfolding time was 2.9 ± 0.9 minutes. Excluding eyes with comorbidities, logarithm of minimum angle of resolution BSCVA improved significantly from baseline preoperative values of 0.92 ± 0.58 to 0.02 ± 0.07 at 1 year (P < .001) and remained stable up to 3 years. Mean postoperative ECD decreased significantly (P < .001) from eye bank values to 1,818 ± 362, 1,675 ± 372, and 1,580 ± 423 cells/mm² at 1, 2, and 3 years, respectively. No significant differences in ECD were observed between eyes with FECD and BK, but ECD was significantly lower in eyes with previous failed graft (P < .05). Three-year cumulative graft survival rate was significantly (P < .001) lower for eyes with previous failed graft (71%) than for FECD (97%) and BK (92%).

CONCLUSIONS

Tri-folded endothelium-in DMEK requires minimal time for graft unfolding, which is the surgical step considered most challenging by corneal surgeons. Visual outcomes and complication rates are not adversely affected by the modification of the surgical technique.

Corneal endothelial dysfunction: Evolving understanding and treatment options

The cornea is exquisitely designed to protect the eye while transmitting and focusing incoming light. Precise control of corneal hydration by the endothelial cell layer that lines the inner surface of the cornea is required for optimal transparency, and endothelial dysfunction or damage can result in corneal edema and visual impairment. Advances in corneal transplantation now allow selective replacement of dysfunctional corneal endothelium, providing rapid visual rehabilitation. A series of technique improvements have minimized complications and various adaptations allow use even in eyes with complicated anatomy. While selective endothelial keratoplasty sets a very high standard for safety and efficacy, a shortage of donor corneas in many parts of the world restricts access, prompting a search for alternatives. Clinical trials are underway to evaluate the potential for self-recovery after removal of dysfunctional central endothelium in patients with healthy peripheral endothelium. Various approaches to using cultured human corneal endothelial cells are also in clinical trials; these aim to multiply cells from a single donor cornea for use in potentially hundreds of patients. Pre-clinical studies are underway with induced pluripotent stem cells, endothelial stem cell regeneration, gene therapy, anti-sense oligonucleotides, and various biologic/pharmacologic approaches designed to treat, prevent, or retard corneal endothelial dysfunction. The availability of more therapeutic options will hopefully expand access around the world while also allowing treatment to be more precisely tailored to each individual patient.

Five-Year Follow-up of First 11 Patients Undergoing Injection of Cultured Corneal Endothelial Cells for Corneal Endothelial Failure

PURPOSE

To report the safety and efficacy of a novel cell injection therapy using cultured human corneal endothelial cells (hCECs) for endothelial failure conditions via the report of the long-term 5-year postoperative clinical data from a first-in-humans clinical trial group.

DESIGN

Prospective observational study.

PARTICIPANTS

This study involved 11 eyes of 11 patients with pseudophakic endothelial failure conditions who underwent hCEC injection therapy between December 2013 and December 2014.

METHODS

All patients underwent follow-up examinations at 1 week, 4 weeks, 12 weeks, and 24 weeks and 1 year, 2 years, 3 years, 4 years, and 5 years after surgery. Specific corneal endothelial cell parameters (i.e., corneal endothelial cell density [ECD], coefficient of variation of area, and percentage of hexagonal cells) and central corneal thickness, best-corrected visual acuity (BCVA) on a Landolt C eye chart, and intraocular pressure (IOP) were recorded.

MAIN OUTCOME MEASURES

The primary outcome was the change in central ECD after cell injection therapy, and the secondary outcome was corneal thickness, BCVA, and IOP during the 5-year-postoperative follow-up period.

RESULTS

At 5 years after surgery, normal corneal endothelial function was restored in 10 of the 11 eyes, the mean ± standard deviation central corneal ECD was 1257 ± 467 cells/mm² (range, 601-2067 cells/mm²), BCVA improved significantly in 10 treated eyes, the mean visual acuity changed from 0.876 logarithm of the minimum angle of resolution before surgery to 0.046 logarithm of the minimum angle of resolution after surgery, and no major adverse reactions directly related to the hCEC injection therapy were observed.

CONCLUSIONS

The findings in this study confirmed the safety and efficacy of cultured hCEC injection therapy for up to 5 years after surgery.

Update on the Surgical Management of Fuchs Endothelial Corneal Dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the most common posterior corneal dystrophy and the leading indication for corneal transplantation in the United States. FECD is slowly progressive, and patients develop gradual corneal endothelial decompensation, eventually resulting in failure of the endothelium to maintain corneal deturgescence. Medical management consists of topical hyperosmotic agents to facilitate dehydration of the cornea, but surgical intervention is often required to regain corneal clarity. The surgical management of FECD has evolved over the past two decades as corneal transplantation techniques have allowed for more selective keratoplasty and replacement of only the diseased layers of the cornea. Prior surgical management consisted of penetrating keratoplasty (PK) that carried significant intraoperative risks associated with "open sky" as well as postoperative risks of graft rejection, wound dehiscence, postoperative astigmatism, and prolonged visual rehabilitation. In the past 15 years, endothelial keratoplasty (EK) has become the treatment of choice for endothelial disease, significantly reducing the risks associated with the surgical treatment of FECD. Here we discuss the current surgical management of FECD, including the introduction of Descemet stripping only (DSO), and highlight future investigative efforts.

Corneal graft failure: an update

Corneal graft surgery is one of the most successful forms of human solid-tissue transplantation, and nowadays, there is a worldwide expansion of the surgical volume of corneal grafts. This surgery is continuously evolving, with new surgical techniques and postoperative treatments that have considerably increased the chance of survival for the grafts. Despite the high rate of success, corneal transplantation is still complicated by a relevant risk of graft failure. This study investigates the causes that lead to the failure of the different corneal graft surgical techniques and provides an updated synthesis on this topic. A comprehensive review of the main pathological pathways that determine the failure of corneal grafts is provided, analysing the main risk factors and disclosing the survival rates of the principal form of corneal grafts. Our results revealed that penetrating keratoplasty has higher failure rates than lamellar keratoplasty, with immunological rejection being the leading cause of graft failure, followed by late endothelial failure (LEF) and ocular surface disorders. Postoperative glaucoma and dehiscence of the surgical wound represent other important causes of failure. Endothelial keratoplasty showed the lowest rates of failure in the mid-term, with LEF, detachment of the graft and primary graft failure representing the most common pathological reasons for failure.

Optimizing pre-Descemet endothelial keratoplasty technique

Pre-Descemet endothelial keratoplasty (PDEK) is an alternative technique to Descemet membrane endothelial keratoplasty (DMEK). The preparation of PDEK tissue by pneumatic dissection is simple and reproducible. The PDEK clamp helps to consistently obtain a type 1 big bubble. The mean size of type 1 big bubble is 7.255 ± 0.535 × 6.745 ± 0.668 mm. The volume of air required to obtain type 1 big bubble is 0.14 to 0.37 mL. Dissection of PDEK tissue can be achieved by trephination or manual excision. Insertion of tissue into the recipient eye can be by injection or pulling. Unfolding techniques used for PDEK are similar to those used in DMEK. Unlike DMEK, PDEK tissue is easier to handle and unscroll and allows use of younger donors. It could help surgeons converting to endothelial keratoplasty, with significant advantages in preparation, handling, and unscrolling in the eye.