Descemet Stripping Only for Fuchs Endothelial Corneal Dystrophy: Will It Become the Gold Standard?

ABSTRACT: Descemet stripping only (DSO) has become a viable treatment option for certain cases of Fuchs Endothelial Corneal Dystrophy (FECD). This article describes the history of the development of DSO, its current status, and what successful DSO tells us about the pathophysiology of FECD. Remaining questions and future directions are also highlighted.

Surgeon Preferences for Endothelial Keratoplasty in Canada.

PURPOSE: To quantify practice patterns and assess attitudes and barriers to performing Descemet membrane endothelial keratoplasty (DMEK) in Canada. METHODS: An anonymous online survey was distributed to all corneal surgeons included in the Canadian Ophthalmological Society's database. RESULTS: Of 70 listed surgeons, 41 responses were collected (58.6% response rate). Most respondents were practicing in university hospitals (43.9%) or private practice (43.9%) and were involved in residency teaching (77.5%). Most respondents performed DMEK surgery (78%), and most surgeons prepared their own DMEK grafts (62%). Surgeons who were in practice for more than 25 years were less likely to perform DMEK (75% vs. 13%, P = 0.009) and performed fewer corneal transplantation in the previous year (mean 28 vs. 44, P = 0.022). Those who were not performing DMEK reported access to preprepared tissue (77.8%), access to wet laboratory courses (50%), and assistance or mentorship (50%) as common facilitators to start performing DMEK surgery. CONCLUSIONS: DMEK is the preferred surgery for endothelial disease among Canadian corneal surgeons. Eye banks play a key role in increased adoption by ensuring an adequate supply of tissue and prestripping tissue for surgeons new to DMEK to be confident in performing it. Ensuring adequate supply of donor tissue and supplementary surgeon training can ensure that DMEK surgery is widely available in Canada.

[Therapeutic Options in Endothelial Decompensation Following Glaucoma Surgery]. / Therapieoptionen bei Endotheldekompensation nach Glaukomchirurgie.

During the last few years, Descemet membrane endothelial keratoplasty (DMEK) has become first line surgical treatment for patients with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy. However, in eyes with previous trabeculectomy or implantation of a glaucoma drainage device, this surgical technique, where the diseased Descemet's membrane and endothelium are replaced by a lamella of donor Descemet's membrane and endothelium, may have some limitations. These include complications during surgery such as difficult unfolding of the graft in the presence of a glaucoma tube with a risk of an increased endothelial cell loss and problems after surgery like the loss of the air/gas tamponade in the anterior chamber through the opening of the trabeculectomy or the tube, with an increased risk of graft dislocation. The following review contains information on endothelial cell loss following different glaucoma operations, discusses the advantages and disadvantages of various keratoplasty techniques and gives some technical advice for improving the surgical technique.

Descemet's membrane endothelial keratoplasty: surgical outcomes and endothelial cell count modelling from a UK centre.

PURPOSE: To report surgical outcomes and endothelial cell density (ECD) trends up to 2 years post-operatively in the first cohort of eyes undergoing Descemet's membrane endothelial keratoplasty (DMEK) for low-to-moderate risk indications at our UK centre. Tight corneal sutures were used to ensure high intraoperative pressure from intracameral air for 10-min and to maintain a good post-operative air fill. Outcomes were compared to a prior series at our unit of similar eyes having Descemet's stripping endothelial keratoplasty (DSEK). METHODS: Retrospective, interventional series. Inclusions: all DMEKs with a minimum of 1-month follow-up. EXCLUSIONS: prior glaucoma surgery, penetrating keratoplasty or anterior chamber lens. RESULTS: 88 DMEKs met inclusion. Median follow-up: 332 days. Main indication: Fuchs dystrophy (90%). COMPLICATIONS: re-bubbling 2%, primary failure 6%, retinal detachment 2%, rejection 3%. At 3 months, BCVA ≥6/6 and ≥6/9 were 67% and 86%, respectively. Graft survival at both 1 and 2 years was 94 ± 2%. Mean(±SD) cell-loss at 1 month, 3 months, 6 months, 12 months and 24 months: 30 ± 15%, 29 ± 16%, 33 ± 17%, 35 ± 17% and 48 ± 16%, respectively. Compared to a prior series at our unit of 210 low-to-moderate risk DSEKs, cell loss was lower for DMEK at all time-points (p < 0.001) through to 12 months but was not statistically different at 24 months. Mixed-modelling of ECD over time demonstrated the convergence of DMEK and DSEK curves by 2 years. CONCLUSIONS: DMEK using tissue from UK eye-banks resulted in high survival and excellent visual acuity. ECD through 1 year was superior to DSEK in a similar cohort. Our low re-bubble rate (2%) may be attributable to use of intracameral air at temporarily elevated intraocular pressure.

Learning DMEK From YouTube.

PURPOSE: To evaluate the outcomes of the first cases of Descemet membrane endothelial keratoplasty (DMEK) performed by an anterior segment surgeon, learning the procedure, including graft preparation, primarily from watching YouTube videos. DMEK surgery was not learned during fellowship training; there was no attendance at DMEK courses, no witnessing of live surgery, and no supervision by an experienced DMEK surgeon. All graft tissue was prepared by the surgeon on the day of surgery. METHODS: This is a retrospective review of the 3-month postoperative results of the first 40 consecutive cases. The success rate of graft preparation, intraoperative and postoperative complications, spectacle-corrected visual acuity, endothelial cell density, and central corneal thickness were evaluated. RESULTS: Grafts were successfully prepared in all cases with no loss of donor tissue. DMEK surgery was successful in 39 of 40 eyes with the one failure occurring in a vitrectomized eye without an intact iris-lens diaphragm. Spectacle-corrected visual acuity was ≥6/6 in 23 of the 25 eyes without comorbidity. Mean endothelial cell density was 1515 (±474) cells/mm. Mean central corneal thickness decreased from 624 (±40) µm preoperatively to 513 (±34) µm postoperatively. CONCLUSIONS: Although formal training is desirable, good results can be obtained by an anterior segment surgeon learning DMEK, including graft preparation, without it. DMEK should no longer be considered a procedure with a long learning curve in routine cases.

Reproducibility of single-pass donor DSAEK tissue preparation with the MORIA single-use microkeratome.

PURPOSE: To assess the reproducibility of single-pass cutting for preparation of ultra-thin (≤120µm) donor cornea grafts in Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: All consecutive patients of DSAEK performed using the MORIA One Use microkeratome (MORIA, Antony, France) in between June 2014 and August 2015. Patient and donor central corneal thickness (CTT), microkeratome head, remaining stromal bed thickness (RSBT), number of cut and graft thickness at 1 month and 6 months postoperatively were recorded in this single-center prospective study. RESULTS: The mean preoperative donor graft CCT was 569.0±45.1µm and the mean donor endothelial graft CCT immediately after the cut was 116.5±28.7µm. At 1 month postoperatively, the mean CCT was 102.8±35.9µm. At 6 months, the mean CCT was 89.4±26.2µm. In all eyes, the mean CCT decreased from the post-cut (116.5±28.7µm) to the last visit (89.4±26.2µm) (P<0.01) due to in vivo deturgesence of the graft. We obtained 77.5% ultra-thin DSAEK immediately after the cut, 77.5% at 1 month and 89.8% after 6 months. CONCLUSION: Single-pass technique with the MORIA One Use microkeratome offers safe and reproducible DSAEK tissue preparation and allows achieving ultra-thin DSAEK in 89.8% of cases.

The First 100 Eyes of Standardized Descemet Stripping Automated Endothelial Keratoplasty versus Standardized Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To compare results of the first 100 eyes of Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) that were performed with a standardized technique at a single institution. DESIGN: Single-center, retrospective case series. PARTICIPANTS: The first 100 eyes of standardized DSAEK and DMEK that underwent surgery for Fuchs corneal dystrophy at our center. We excluded patients with prior ocular surgery other than cataract surgery to limit confounding variables. METHODS: Best spectacle-corrected visual acuity (BSCVA; in logarithm of the minimal angle of resolution [logMAR] units) was obtained and specular microscopy of donor corneal tissue was performed before surgery. Postoperative complications, BSCVA, and the percent of endothelial cell loss (ECL) recorded at 6 months were compared with the Student t test. Patients with pre-existing ocular comorbidity that impacted visual potential such as macular degeneration, amblyopia, advanced glaucoma, and other optic neuropathies were excluded from the analysis of visual acuity, but were included for the outcomes of complications and ECL. MAIN OUTCOME MEASURES: Visual acuity improvement, ECL 6 months after surgery, postoperative complications, iatrogenic primary graft failure (IPGF), and rebubbling. RESULTS: Of the 200 eyes, 62 DSAEK eyes and 70 DMEK eyes had 6-month BSCVA available and no vision-limiting comorbidities. Mean BSCVA increased from 0.41±0.19 logMAR and 0.27±0.11 logMAR before surgery to 0.20±0.13 logMAR and 0.11±0.13 logMAR 6 months after DSAEK and DMEK, respectively (P<0.001). Seventy-one DSAEK eyes and 70 DMEK eyes had 6-month ECL data available: ECL was 25.9±14.0% after DSAEK and 27.9±16.0% after DMEK (P=0.38). There were no IPGFs in the DSAEK cohort and there were 4 of 100 IPGFs after DMEK (P=0.12). Rebubbling was performed in 2 of 100 eyes after DSAEK and in 6 of 100 eyes after DMEK (P=0.28). CONCLUSIONS: Compared with DSAEK, DMEK provided better visual recovery and comparable 6-month ECL. The DMEK group had a higher, although not statistically significant, percentage of rebubbling procedures and IPGFs.

Standardized DMEK Technique: Reducing Complications Using Prestripped Tissue, Novel Glass Injector, and Sulfur Hexafluoride (SF6) Gas.

PURPOSE: To report low complication rates in Descemet membrane endothelial keratoplasty (DMEK) using sulfur hexafluoride (SF6) gas, a novel glass injector, and donor tissue prestripped by an eye bank technician. METHODS: A standardized technique of DMEK was performed in 80 consecutive Fuchs corneal dystrophy cases using technician-prestripped tissue, a novel glass injector, a modified Yoeruek tap technique, and an SF6 gas (20% concentration) bubble for prolonged tissue support. Twenty-five donors were premarked with an "S" stamp for intraoperative orientation. Surgery was performed by 2 experienced DMEK surgeons and 2 inexperienced cornea fellows. Complications were recorded, and the percent endothelial cell loss was calculated at 6 months postoperatively. RESULTS: There were 5 cases that received an air bubble injection postoperatively (6% rebubble rate). There were 6 grafts that immediately failed, 2 because of excessive surgical trauma, and 4 because of upside-down graft placement documented by optical coherence tomography. None of the 25 cases with an S stamp failed. Recipient corneas cleared quickly with no clinical evidence of toxicity from the SF6 gas bubble, and the grafts experienced a mean endothelial cell loss of 27% at 6 months. CONCLUSIONS: Tissue prestripped by an eye bank technician can be safely used for DMEK surgery. SF6 gas for prolonged tissue support may reduce the rebubble rate in DMEK, with no apparent acute toxic effect. An unrecognized upside-down graft was the primary cause of graft failure in this series. Upside-down grafts may be eliminated by the use of donor tissue premarked by the eye bank with an S orientation stamp.

Standardization of the Descemet membrane endothelial keratoplasty technique: Outcomes of the first 450 consecutive cases.

OBJECTIVES: To evaluate the clinical outcome of the first 450 consecutive cases after Descemet membrane endothelial keratoplasty (DMEK), as well as the effect of standardization of the technique. MATERIAL AND METHODS: Comparison between 3 groups: Group I: (cases 1-125), as the extended learning curve; Group II: (cases 126-250), transition to technique standardization; Group III: (cases 251-450), surgery with standardized technique. Best corrected visual acuity, endothelial cell density, pachymetry and intra- and postoperative complications were evaluated before, and 1, 3 and 6 months after DMEK. RESULTS: At 6 months after surgery, 79% of eyes reached a best corrected visual acuity of≥0.8 and 43%≥1.0. Mean preoperative endothelial cell density was 2,530±220 cells/mm2 and 1,613±495 at 6 months after surgery. Mean pachymetry measured 668±92 µm and 526±46 µm pre- and (6 months) postoperatively, respectively. There were no significant differences in best corrected visual acuity, endothelial cell density and pachymetry between the 3 groups (P > .05). Graft detachment presented in 17.3% of the eyes. The detachment rate declined from 24% to 12%, and the rate of secondary surgeries from 9.6% to 3.5%, from group I to III respectively. CONCLUSIONS: Visual outcomes and endothelial cell density after DMEK are independent of the technique standardization. However, technique standardization may have contributed to a lower graft detachment rate and a relatively low number of secondary interventions required. As such, DMEK may become the first choice of treatment in corneal endothelial disease.

Estimation of the effects of rounding visual acuity data.

AIMS: To examine the effect of rounding of visual acuity data on estimates of surgical performance. METHOD: In this observational study, the distribution of 1-year Snellen visual acuity data from 606 endothelial keratoplasties from the NHSBT UK transplant database was analysed. A curve was fitted to the data and used to estimate the frequencies of partly read Snellen lines. The estimates were used to create a virtual database of grafts with Snellen acuities that included individual letter scores. The virtual database was then sampled to produce datasets for 10 virtual surgeons. Various acuity analysis methods were then applied to simulate possible effects of surgeons rounding their data. RESULTS: Rounding of acuity data was found to have a notable effect on estimates of surgeons' success rates. When a criterion of 6/12 or better was applied, the success rates ranged from 62% to 80% using a conservative method of estimation but ranged from 80% to 94% using a less conservative method. CONCLUSIONS: Rounding of visual acuity scores is an important potential bias in outcome data and should be avoided. If rounding is required we recommend that it is carried out conservatively, giving credit only for lines read completely.

[Standardized Descemet membrane endothelial keratoplasty (DMEK): technique and latest results]. / Standardisierte Descemet-Membran-Endothelkeratoplastik (DMEK) : Technik und aktuelle Ergebnisse.

BACKGROUND: The procedure of posterior lamellar keratoplasty has now become established as first choice therapy for the treatment of corneal endothelial diseases, with Descemet membrane endothelial keratoplasty (DMEK) as the most recent refinement of endothelial keratoplasty techniques. In this study the outcome of 400 consecutive cases after standardized no-touch DMEK was evaluated. METHODS: This was a non-randomized retrospective clinical study of 400 consecutive eyes in 321 patients who underwent standard DMEK. Outcome measures included best corrected visual acuity (BCVA) preoperatively and postoperatively at 1, 3 and 6 months, endothelial cell density (ECD), pachymetry and complications within the first 6 months. In addition two subgroups were analyzed (subgroup I cases 1-200 and subgroup II cases 201-400). RESULTS: At 6 months postoperatively 80 % of all eyes had a BCVA of ≥ 20/25 (≥ 0.8), 44 % of ≥ 20/20 (≥ 1.0) and 14 % of ≥ 20/18 (≥ 1.2). There were no significant differences between the two subgroups. The mean ECD preoperatively was 2,542 (± 217) cells/mm(2) and 6 months postoperatively 1,622 (± 500) cells/mm(2). The mean ECD decrease was 36 % 6 months after DMEK. No difference between the subgroups was noted. In 5 % a re-operation was needed of which 75 % were performed in subgroup I. CONCLUSION: With the standardized no-touch DMEK technique a rapid and nearly complete visual rehabilitation as well as ECD values similar to earlier endothelial keratoplasty techniques can be achieved. Therefore DMEK may become the preferred treatment for corneal endothelial disorders.

Standardized "no-touch" technique for descemet membrane endothelial keratoplasty.

We describe a standardized technique for "no-touch" isolated Descemet membrane transplant, ie, Descemet membrane endothelial keratoplasty (DMEK). All essential steps, including patient preparation and descemetorhexis as well as DMEK graft implantation, orientation, unrolling, centering, appositioning, and fixation, are described in detail. In the management of Fuchs endothelial dystrophy, the technique may provide a best-corrected visual acuity of 20/25 or better (≥ 0.8) in three-quarters of cases and an endothelial cell density of about 1800 to 2000 cells/mm(2) at 6 months after surgery. No-touch DMEK may therefore be a safe and effective procedure for the treatment of corneal endothelial disorders, making endothelial keratoplasty accessible to most corneal surgeons without requiring major investments while providing an unprecedented visual rehabilitation rate and outcome.