Contralateral eye comparison of descemet membrane endothelial keratoplasty and descemet stripping automated endothelial keratoplasty

Descemet Membrane Endothelial Keratoplasty in Corneal Endothelial Decompensation After a Forceps-Induced Corneal Birth Injury: Case Series and Technique

PURPOSE

The aim of this study was to describe the efficacy of Descemet membrane endothelial keratoplasty (DMEK) in patients with corneal endothelial decompensation secondary to a forceps-induced corneal birth injury.

METHODS

This was a retrospective, noncomparative, interventional case series. Four eyes of 4 patients (1 female and 3 males; mean age, 64.0 ± 4.7 years) with corneal endothelial decompensation due to forceps-induced corneal birth injury were included. DMEK was performed in all cases, using a combined technique, including the use of intraoperative optical coherence tomography, vital staining of Descemet membrane of both host and donor, removal of scarred Descemet membrane with side-port forceps and vitreous cutter to smoothen the posterior corneal surface, epithelial peeling, and illumination for visualization. The examination included preoperative and postoperative ophthalmologic examinations: best-corrected visual acuity (converted to logarithm of the minimum angle of resolution [logMAR]), intraocular pressure, endothelial cell density (ECD), and central corneal thickness.

RESULTS

No postoperative complications were noted, and corneal transparency was maintained during follow-up (mean follow-up period, 32.0 ± 27.0 months; range, 3-71 months). The mean best-corrected visual acuity was 0.52 ± 0.35 logMAR preoperatively and 0.15 ± 0.09 logMAR at the last visit. The mean postoperative ECD was 1632 ± 631 cells/mm 2 (mean ECD at baseline, 3167 cells/mm 2 ). Central corneal thickness decreased from 640 ± 67 μm preoperatively to 576 ± 58 μm postoperatively.

CONCLUSIONS

This study suggests that DMEK can be performed uneventfully in eyes with a forceps-induced corneal birth injury. The combination of surgical techniques may be an effective approach for DMEK.

Performance outcomes from a DMEK peeling and preparation wet lab

OBJECTIVE

To evaluate the Descemet membrane endothelial keratoplasty (DMEK) preparation performance of trainee surgeons in an ex vivo human donor cornea DMEK wet lab simulation setting.

METHODS

Human donor corneoscleral rims unsuitable for transplantation were obtained from Moorfields Lions Eye Bank. At the wet lab, graft stripping was performed by scoring the peripheral endothelium. The trypan blue positive cells (TBPC) and cell density (cells/mm2-reticule count) were counted manually before and after stripping. The procedural time, peripheral and central tears and complete peel-off were also recorded and analysed.

RESULTS

Eight trainee surgeons attended the wet lab each attempting three DMEKs. Between the first and last attempts a significant decrease was seen in the procedural time (17.6 min vs 10.6 min (p<0.05)) and the TBPC % (12.9% vs 3.8% (p<0.05)). The percentage of tears peripherally and centrally also reduced between the first and the last trials (50% vs 13% (p=0.2226) and 38% vs 0% (p=0.1327)). A significant correlation was found between longer peeling times and higher TBPC % (p<0.001) with a 0.7% endothelial mortality increase for each additional minute required to complete the peel.

CONCLUSIONS

DMEK wet labs provide a controlled risk-free learning opportunity for trainee surgeons to improve confidence and competence. Wet labs improve the success rate of DMEK graft preparation as well as flatten the learning curve. This emphasises the importance of continued support for the expansion of this valuable learning resource, promoting wider uptake of DMEK surgery.

Descemet Membrane Endothelial Keratoplasty with cornea press technique and implantation of a Carlevale scleral-fixated intraocular lens

Purpose

We describe a combined Descemet Membrane Endothelial Keratoplasty (DMEK) using the Cornea-press (C-Press) technique, with implantation of a new sutureless, scleral fixated intraocular lens (IOL) (Carlevale, Soleko), in a case of bullous keratopathy and IOL mispositioning.

Observations

Two scleral pockets were created along two scleral radial incisions, 180° apart, followed by two 23 G sclerotomies at the pockets' sites. After removal of the dislocated IOL through a corneoscleral incision, posterior vitrectomy was completed. The Carlevale IOL was injected into the anterior chamber (AC) and placed above the iris. The haptics were then externalized using opening distal forceps through the sclerotomies, and the plugs were secured in the scleral pockets. DMEK was then performed using the "C-press" technique, where corneal indentation allowed to artificially shallow the AC to ensure successful graft unrolling. Fifteen months postoperatively, the cornea was clear, the Carlevale IOL well positioned, and the patient's vision improved.

Conclusions and importance

DMEK using the C-Press technique, combined with a sutureless, scleral-fixated IOL such as the Carlevale in a single procedure, may be a safe and effective option to restore vision in case of bullous keratopathy and dislocated IOL.

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.

DMEK surgical training: An instructional guide on various wet-lab methods

Descemet membrane endothelial keratoplasty (DMEK) is a partial-thickness corneal transplantation procedure that involves selective transplantation of the Descemet membrane and endothelium. DMEK offers significant advantages over other keratoplasty techniques, such as faster visual rehabilitation, better final visual acuity due to minimal optical interface effects, lower risk of allograft rejection, and less long-term dependence on topical steroids. Despite all its advantages, DMEK has been found to be more challenging than other corneal transplantation techniques, and its steep learning curve appears to be an obstacle to its widespread use and adoption by corneal surgeons worldwide. DMEK surgical training laboratories (wet labs) provide a window of opportunity for surgeons to learn, prepare, manipulate, and deliver these grafts in a risk-free environment. Wet labs are a significant learning tool, especially for those institutions that have limited tissue availability in their local centers. We provide a step-by-step guide for preparing DMEK grafts using different techniques on human and nonhuman models with instructional videos. This article should eventually help the trainees and the educators understand the requirements for performing DMEK and conducting a DMEK wet lab and develop their skills and interests from a wide variety of available techniques.

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.

Risk factors for intraocular pressure elevation following Descemet membrane endothelial keratoplasty in Asian patients

PURPOSE

To investigate risk factors for increased intraocular pressure (IOP) after Descemet membrane endothelial keratoplasty (DMEK) in Asian patients.

METHODS

Data from January 2015 to February 2021 were obtained from our prospective database. IOP elevation after DMEK was defined as IOP ≥ 22 mmHg or an increase in IOP of ≥ 10 mmHg from baseline. In addition, we examined maximum IOP. Using iCare, we measured IOP 1, 2, 3, and 6 months after DMEK, and every 6 months thereafter. Logistic regression and linear regression were performed to find factors predictive of IOP elevation and maximum IOP, respectively, based on the results of univariate analysis.

RESULTS

We enrolled 90 eyes (mean patient age, 74.9 ± 7.5 years; mean follow-up duration, 25.6 ± 9.9 months) that underwent DMEK. IOP elevation was present in 19 eyes (21%). IOP increased from 12.6 ± 3.9 mmHg preoperatively to a postoperative maximum of 17.0 ± 5.5 mmHg up to 36 months after DMEK (p < 0.0001). In univariate logistic regression analysis for IOP elevation, only one variable, pseudoexfoliation syndrome (PEX) and preexisting glaucoma, was significant (p < 0.05). Preexisting glaucoma without PEX (OR, 19.33; 95% CI, 4.75-93.46), PEX without glaucoma (OR, 7.25; 95% CI, 1.20-41.63), and PEX glaucoma (OR, 58.00; 95% CI, 6.78-1298.29) were associated with higher risk of IOP elevation.

CONCLUSIONS

In this cohort, the eyes of patients with PEX and preexisting glaucoma were found to be prone to IOP elevation after DMEK.

Posterior Segment Air Injection-Assisted Descemet Membrane Endothelial Keratoplasty in Pseudophakic and Vitrectomized Eyes

PURPOSE

This study aimed to present a novel technique for Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic and vitrectomized eyes.

METHODS

The sterile air was injected into the posterior eye segment (anterior vitreous cavity) as a barrier to prevent the fluid of the vitreous cavity flowing into the anterior chamber, levitating the iris-lens diaphragm to flatten the anterior chamber during the surgery. This approach assists in the unfolding of the donor endothelial graft, helping to perform DMEK surgery on patients with a posterior intraocular lens (IOL) and vitrectomy.

RESULTS

Four cases presented with corneal endothelial decompensation (pseudophakic bullous keratopathy) with previous IOL implantation and vitrectomy underwent DMEK with this technique. The Descemet endothelial graft unfolding time after air injection was 68.75 ± 8.96 seconds. No graft displacement occurred during the surgery. The uncorrected and corrected distance visual acuities were improved in 3 of 4 patients. The corneas were transparent, and there was no graft detachment observed postoperatively in all 4 patients.

CONCLUSIONS

The posterior eye segment air injection can reduce the difficulty of unfolding the DMEK graft in patients after IOL implantation and vitrectomy and the potential intraoperative and postoperative complications, allowing for easy performance of DMEK surgery on pseudophakic and vitrectomized eyes for corneal endothelial dysfunction.

Assessing the Learning Curve for DMEK Using Post-Procedural Clinical Outcomes-Comparison of Four Different Surgeons during Two Different Periods

PURPOSE

Evaluating the learning curve of individual surgeons for Descemet Membrane Endothelial Keratoplasty (DMEK) and Triple-DMEK and assessing outcome with experience.

METHODS

The first 41 and the last 41 surgeries of each of the four surgeons were retrospectively included. Surgery duration and graft preparation time were recorded. Corrected distance visual acuity (CDVA, logMAR) and central corneal thickness (CCT, µm) were collected preoperatively after 6 and 12 months, as well as postoperative complications, e.g., re-bubbling or repeat penetrating keratoplasty.

RESULTS

Surgical duration for Triple-DMEK and DMEK decreased significantly by 21 min and 14 min between the two periods (p < 0.001; p < 0.001). Graft preparation time decreased significantly from 13.3 ± 5.2 min (95%CI 12.8-14.3) in period 1 to 10.7 ± 4.8 min (95%CI 10.2-11.4) in period 2 (p = 0.002). The postoperative changes in CDVA and CCT over both periods were not significant (p = 0.900; p = 0.263). The re-bubbling rate decreased significantly from 51.2% in period 1 to 26.2% in period 2 (p < 0.001). The repeat penetrating keratoplasty (PKP) was 7.3% in period 1 and 3.7% in period 2 (p = 0.146). Re-DMEK was necessary in 6.1% in period 1 and 4.9% in period 2 (p = 0.535). Several parameters showed significant differences between the surgeons in both periods (surgical duration: period 1: p < 0.001, period 2 p < 0.001; graft preparation: period 1: p < 0.001, period 2 p < 0.001).

CONCLUSION

Significant decrease in surgery duration, graft preparation time, and the re-bubbling rate can be attributed to gained individual experience.

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

PURPOSE

This study aimed to evaluate the clinical outcomes up to 10 years after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

In this retrospective, consecutive, single-center case series the medical files of eyes which have received DMEK between 2009 and 2012 for the treatment of endothelial dysfunction was evaluated regarding follow-up time and clinical outcomes. Annual examinations of best-corrected visual acuity (BCVA), endothelial cell density (ECD), central corneal thickness (CCT) of 66 eyes which fulfilled the criterion of a minimum of 8 years follow-up were analyzed.

RESULTS

BCVA improved from 0.55 ± 0.37 logMAR (n = 54) to 0.15 ± 0.11 (n = 47) in eyes without ocular comorbidities one year after DMEK (p < 0.001), and remained stable up to 10 years after DMEK. Mean ECD decreased to 744 ± 207 cells/mm2 (n = 39) after 9 years, and to 729 ± 167 cells/mm2 (n = 21) after 10 years, respectively. CCT decreased from 650 ± 67 μm before DMEK to 525 ± 40 μm (n = 56) after 1 year, increasing slowly to 563 ± 40 µm (n = 39) after 9 years, and to 570 ± 42 µm (n = 21) after 10 years, respectively. Graft failure occurred in 4 of 66 eyes after year 8. These 4 eyes required repeat DMEK after 101-127 months.

CONCLUSION

This study shows the long-term outcomes in a small subset of DMEK grafts. Visual acuity remained stable in spite of slowly increasing corneal thickness and diminishing endothelial cell density during the 10-year period after DMEK.

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.

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

PURPOSE

To investigate changes of corneal thickness spatial profile (CTSP), corneal volume (CV) distribution, and total corneal refractive power (TCRP) over a course of 60 months after uneventful Descemet membrane endothelial keratoplasty (DMEK).

METHODS

In our prospective, comparative study, sixty DMEK cases without intraoperative and postoperative complications and with complete 60-month follow-up were included (group 1). CTSP at corneal apex (CCT) and at 2 mm, 4 mm, 6 mm, and 8 mm rings, CV in 3 mm, 5 mm, 7 mm, and 10 mm zones, and TCRF in 2 mm, 4 mm 6 mm, and 8 mm zones were evaluated preoperatively and at 3, 6, 12, 24, and 60 months postoperatively. The 60-month results were compared to an age-matched group of uncomplicated pseudophakic eyes (group 2; n = 20).

RESULTS

The CCT and CTSP at 2, 4, and 6 mm increased significantly at 60 months compared to 3-month outcomes (P < 0.001). Similarly, CV increased significantly in 3 mm, 5 mm, and 7 mm zones at 60 months compared to 3 months outcomes (P < 0.001). The TCRP showed in all zones a significant decrease at 3 months (P < 0.001) followed by a continuous and significant increase at 60 months (P < 0.001). The 60-month CCT and CTSP at 2 mm were similar to group 2 (P ≥ 0.094).

CONCLUSION

Sixty months after uneventful DMEK, CT within the central 2 mm zone and CV at 3 mm zone were similar to uncomplicated pseudophakic eyes. A continuous and statistically significant increase of TCRP was observed in all measured zones after the 3-month examination.

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.

Effective Cannula Vacuuming Maneuver to Unfold the Descemet Membrane Graft

OBJECTIVES

To present the cannula vacuuming maneuver (CVM) in the Descemet membrane endothelial keratoplasty (DMEK) and to investigate the efficacy of CVM in reducing the unfolding time (UT) of the graft in cases with an unstable anterior chamber (AC).

SUBJECTS/METHODS

Forty-four eyes of 44 patients, who underwent DMEK at the ophthalmology clinic of a training and research hospital, were included in this retrospective study. Surgical videos and patient charts were examined retrospectively. In 21 cases, only no-touch technique maneuvers were used (group 1), and in 23 cases, CVM was used in addition to the no-touch technique (group 2). Demographic data, the status of AC, graft diameter, width, and formation of graft rolls and UT were recorded and compared between the groups. The causes of increased UT and the reason for using CVM were investigated in group 2.

RESULTS

Although an unstable AC was observed more frequently in group 2, the difference between the groups was not statistically significant (P=0.054). Unfolding time of rolls in group 2 was significantly shorter than group 1 (P=0.040).

CONCLUSION

Cannula vacuuming maneuver shortens the UT of the graft roll in the AC and facilitates the graft unfolding maneuvers in complicated cases.

Corneal Densitometry After Uneventful Descemet Membrane Endothelial Keratoplasty-5-Year Outcomes

PURPOSE

The purpose of this study is to analyze the course of corneal densitometry (CD), endothelial cell density (ECD), best-corrected visual acuity (BCVA), and central corneal thickness (CCT) 5 years after uneventful Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Sixty uneventful cases (51 patients) with a minimum follow-up of 5 years were included. CD of various corneal layers (anterior, central, posterior, and total layer) and zones (0-2 mm, 2-6 mm, and 6-10 mm) were measured with Scheimpflug tomography. ECD, BCVA, and CCT were also evaluated.

RESULTS

Total CD at 0 to 2 mm and 2 to 6 mm zones significantly decreased from 33 ± 10 and 27.8 ± 8 grayscale units (GSU) preoperatively to 21.8 ± 3.1 and 22.2 ± 4.2 GSU at 5 years, respectively (P < 0.001). On the contrary, total CD at the 6 to 10 mm zone significantly increased from 30 ± 8.3 GSU preoperatively to 34.6 ± 7.8 GSU at 5 years (P < 0.001). ECD significantly decreased from 2496 ± 267 cells/mm2 preoperatively to 1063 ± 470 cells/mm2 at 5 years (P < 0.001). Similarly, CCT significantly decreased from 686 ± 109 μm preoperatively to 557 ± 37 μm at 5 years (P < 0.001). Postoperative BCVA was significantly better after DMEK for every examination time point.

CONCLUSIONS

Despite a slight CD increase at all layers of all corneal zones from the second to the fifth postoperative year, the excellent visual outcome was maintained throughout 5-year follow-up. Thus, DMEK seems to effectively treat corneal endothelial disease in the long term.

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.

Four-Year Survival Comparison of Endothelial Keratoplasty Techniques in Patients With Previous Glaucoma Surgery

PURPOSE

To compare 4-year survival outcomes of Descemet membrane endothelial keratoplasty (DMEK) and Descemet-stripping automated endothelial keratoplasty (DSAEK) in eyes with previous glaucoma surgery.

METHODS

This is a retrospective, comparative case series, including patients with previous trabeculectomy or glaucoma drainage device implantation, who later underwent either DMEK (n = 48) or DSAEK (n = 41). Follow-up was limited to 12 to 60 months to prevent bias. Primary outcomes were graft survival and rejection. Secondary outcomes were best spectacle-corrected visual acuity (BSCVA), detachment/rebubble, endothelial cell loss, and intraocular pressure elevations.

RESULTS

Baseline characteristics, follow-up duration, and preexisting glaucoma parameters did not differ significantly between the groups. Graft survival probability after DMEK and DSAEK was 75% and 75% at 1 year, 63% and 50% at 2 years, 49% and 44% at 3 years, 28% and 33% at 4 years, and 28% and 29% at 5 years, respectively (P = 0.899 between the groups). Graft rejection rates were 20.8% and 19.5%, respectively (P = 1.000). Primary failure, rebubbling, endothelial cell loss, and intraocular pressure elevation did not differ significantly between the groups. Preoperative BSCVA did not differ between the groups (P = 0.821). Postoperative BSCVA was significantly better in the DMEK group at 6, 12, and 24 months (P < 0.001, P = 0.022, and P = 0.047, respectively). In a multivariable model (R2 = 0.576), the type of surgery was the only significant factor affecting postoperative BSCVA, in favor of DMEK (coefficient value -0.518, P = 0.002).

CONCLUSIONS

In eyes with previous glaucoma surgery, DMEK and DSAEK had comparably low survival and comparably high rejection rates. Postoperative visual acuity might be better after DMEK in this setting.

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.

Lower Corneal Haze and Aberrations in Descemet Membrane Endothelial Keratoplasty Versus Descemet Stripping Automated Endothelial Keratoplasty in Fellow Eyes for Fuchs Endothelial Corneal Dystrophy

PURPOSE

To investigate the long-term corneal changes in patients with Fuchs endothelial corneal dystrophy contributing to superior postoperative visual outcomes after Descemet membrane endothelial keratoplasty (DMEK) compared with Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

Using retrospective analysis, we evaluated 9 patients with Fuchs endothelial corneal dystrophy who underwent DSAEK in 1 eye and DMEK in the fellow eye. Patients were genotyped for the triplet repeat expansion in the TCF4 gene and imaged using optical coherence tomography, Scheimpflug imaging, and in vivo confocal microscopy through focusing.

RESULTS

Eight of 9 subjects were genotyped, and all were found to harbor the triplet repeat expansion. The average time between endothelial keratoplasty and imaging was 76 ± 22 and 37 ± 9 months after DSAEK and DMEK, respectively. The mean best spectacle-corrected visual acuity (logMAR) was 0.04 ± 0.05 and 0.11 ± 0.03 in the DMEK eyes versus DSAEK eyes (P = 0.02), respectively. Posterior corneal higher order aberrations were less in the DMEK eyes compared with fellow DSAEK eyes (0.25 ± 0.06 and 0.66 ± 0.25, respectively, P ≤ 0.01). Using confocal microscopy through focusing, we found that the persistent anterior stromal haze was correlated between the right and left eyes (R = 0.73, P ≤ 0.05), but total stromal backscattering was higher for the DSAEK eyes (P ≤ 0.05).

CONCLUSIONS

DSAEK inherently results in higher total stromal backscattering (haze) compared with DMEK because of the addition of stromal tissue. Lower higher order aberrations of the posterior cornea and lower total stromal backscattering (haze) may both contribute to superior visual outcomes after DMEK compared with DSAEK.

Effects of uncomplicated Descemet membrane endothelial keratoplasty on the central retinal thickness

Purpose

To determine retinal thickness (RT) changes and the incidence of macular edema after uncomplicated Descemet membrane endothelial keratoplasty (DMEK-ME) in patients without ME risk factors.

Methods

In this retrospective study, 107 pseudophakic eyes of 74 patients with Fuchs endothelial dystrophy (FED) (79.4%) or bullous keratopathy (BK) (20.6%) underwent DMEK surgery between 2016 and 2019 at the Department of Ophthalmology, RWTH Aachen University. Patients with intra- or postoperative complications as well as pre-existing risk factors for ME were excluded. Macular spectral-domain optical coherence tomography (SD-OCT) and best spectacle-corrected visual acuity (BSCVA) measurements were performed before, 1 week, 1 month, and 6 months after surgery. Retinal thickness (RT) was analyzed in the central foveal 1 mm (CSF), parafoveal 3 mm and 6 mm subfield.

Results

Eight eyes (7.5%) developed DMEK-ME 1 month after surgery. Six DMEK-ME eyes (75%) were rebubbled, compared with 31.3% (31 of 99; P = 0.02) of the non DMEK-ME eyes. DMEK-ME eyes had a significantly thicker CSF 1 month after surgery (432.0 ± 97.6 μm) compared with non-DMEK-ME eyes (283.7 ± 22.2 μm; P = 0.01). The other subfields and time points showed no significant RT changes. DMEK-ME significantly impaired BSCVA (0.38 ± 0.92 logMAR) only 1 month after surgery in comparison to the non DMEK-ME eyes (0.23 ± 0.87 logMAR, P = 0.015).

Conclusion

Excluding systemic and surgery-related risk factors, rebubbling increases the risk of DMEK-ME. Performing a CSF scan 1 month after surgery, particularly in rebubbled eyes, efficiently detects DMEK-ME and allows the prompt initiation of treatment, e.g., topical corticosteroid and non-steroidal (NSAID) eye drops.

Femtosecond laser-assisted descemetorhexis for Descemet membrane endothelial keratoplasty: a cell- and tissue-based ex-vivo analysis in terms of precision and safety

PURPOSE

To analyze precision and safety of femtosecond laser-assisted descemetorhexis as well as postoperative corneal wound healing in human ex vivo specimens.

SETTING

Department of Ophthalmology, University Hospital, LMU Munich, Munich, Germany.

DESIGN

Experimental ex vivo study.

METHODS

Four donor corneas underwent femtosecond laser-assisted descemetorhexis. The descemetorhexis was performed using the LDV Z8 femtosecond laser followed by live/dead staining, phase contrast microscopy and scanning electron microscopy. The descemetorhexis parameters were set using a modified optical coherence tomography image capturing of 8 segments within a focus of 100 μm at the posterior corneal stroma (reversed capsulotomy program).

RESULTS

Live/dead sample staining analysis demonstrated that the femtosecond laser had minimal impact on the vitality of surrounding endothelial cells. Phase contrast microscopy and scanning electron microscopy evaluation showed that the laser produced precise, clear-cut edges leaving no stromal tissue bridges.

CONCLUSIONS

Femtosecond laser-assisted descemetorhexis could serve as a safe and precise technique with only minimal endothelial cell damage. To minimize stromal damage, further laser energy profile adjustments are necessary to optimize corneal treatment within different stages of corneal tissue swelling.

Evolution of therapies for the corneal endothelium: past, present and future approaches

Corneal endothelial diseases are leading indications for corneal transplantations. With significant advancement in medical science and surgical techniques, corneal transplant surgeries are now increasingly effective at restoring vision in patients with corneal diseases. In the last 15 years, the introduction of endothelial keratoplasty (EK) procedures, where diseased corneal endothelium (CE) are selectively replaced, has significantly transformed the field of corneal transplantation. Compared to traditional penetrating keratoplasty, EK procedures, namely Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK), offer faster visual recovery, lower immunological rejection rates, and improved graft survival. Although these modern techniques can achieve high success, there are fundamental impediments to conventional transplantations. A lack of suitable donor corneas worldwide restricts the number of transplants that can be performed. Other barriers include the need for specialized expertise, high cost, and risks of graft rejection or failure. Research is underway to develop alternative treatments for corneal endothelial diseases, which are less dependent on the availability of allogeneic tissues - regenerative medicine and cell-based therapies. In this review, an overview of past and present transplantation procedures used to treat corneal endothelial diseases are described. Potential novel therapies that may be translated into clinical practice will also be presented.

Descemet membrane endothelial keratoplasty in vitrectomized eyes: a case series of outcomes and complications

BACKGROUND

The aim of this study was to evaluate the clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) in vitrectomized eyes.

METHODS

A multi-surgeon, retrospective case series of previously vitrectomized eyes that underwent DMEK between 2013 and 2018 at Moorfields Eye Hospital. Patients' demographics, preoperative, intraoperative and postoperative data were collected.

RESULTS

In total, 14 eyes of 13 patients, aged 63 ± 14.6 years were included. Three eyes had intraoperative posterior dislocation of the DMEK graft into the vitreous cavity, two of these were aphakic and one had an unstable PCIOL. Postoperatively, one graft had a total detachment and required repeat keratoplasty for primary failure, two grafts had visually significant partial detachment and needed rebubbling. Three patients developed high intraocular pressure (IOP) and one required an urgent glaucoma drainage device 1-month post-DMEK. The mean corrected distance visual acuity was 0.81 ± 0.42 logMAR preoperatively, and postoperatively was 0.6 ± 0.51 at 3 months (p = 0.414); 0.69 ± 0.81 at 6 months (p = 0.684); and 0.7 ± 0.8 at 12 months (p = 0.658).

CONCLUSIONS

DMEK in vitrectomized eyes has unique challenges that necessitate careful preoperative planning. We observed a significant proportion of dislocated grafts in vitrectomized eyes with either unstable IOL or aphakic. Moreover, vitrectomized eyes with secondary glaucoma may be particularly vulnerable to uncontrolled IOP postoperatively and close monitoring is essential to prevent worsening of visual acuity. We recommend that DMEK may not be a feasible option in eyes that are prone to collapse, in particular aphakic vitrectomized eyes, as opposed to DSAEK or penetrating keratoplasty.

Descemet Membrane Endothelial Keratoplasty and light adjustable lens triple procedure

Purpose

The objective of this series is to report the early post-operative visual outcomes of a novel triple procedure utilizing Descemet membrane endothelial keratoplasty (DMEK) plus light adjustable lens (LAL) in two patients (four eyes).

Methods

Two patients with bilateral, visually significant cataracts and Fuchs' dystrophy were selected for DMEK plus LAL triple procedure. Patient B also exhibited a high amount of preoperative astigmatism. Both patients desired spectacle independence and were initially targeted for monovision with the dominant eye corrected for distance and the nondominant eye corrected for near. Best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), and manifest refraction were recorded at each postoperative appointment and light treatment.

Results

In the early post-operative course, Patient A chose to pursue binocular distance correction instead of monovision. This was adjusted for accordingly using the LAL. Following final lock-in, Patient A had a distance UCVA of 20/15 in the right eye (OD) and a distance UCVA of 20/20 in the left eye (OS). Patient B was targeted for monovision. After final lock-in, Patient B had a distance UCVA of 20/15 in the dominant eye (OD) and a near UCVA of Jaeger No. 1+ in the nondominant eye (OS).

Conclusions and Importance

The first reported cases of DMEK plus LAL triple procedures achieved exceptional UCVA at the desired target. The post-operative customizability of the LAL allows for the achievement of excellent refractive outcomes after DMEK, even in patients with significant astigmatism and in patients who change their mind regarding refractive target.

Visual Quality and Subjective Satisfaction in Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK) versus Descemet Membrane Endothelial Keratoplasty (DMEK): A Fellow-Eye Comparison

BACKGROUND

To analyze objective and subjective visual quality differences between descemet membrane endothelial keratoplasty (DMEK) and ultra-thin descemet stripping automated endothelial keratoplasty (UT-DSAEK) with a paired contralateral-eye design.

METHODS

A cross-sectional, comparative, and observational case series study between DMEK and UT-DSAEK were presented. Visual acuity, refractive status and corneal quality assessment were compared between both endothelial keratoplasty techniques. The sample consisted of 20 eyes (10 patients) diagnosed with Fuchs endothelial corneal dystrophy. All measurements were performed preoperatively and at six months after surgery. Analyzed data included the measurement of objective scattering index, modulation transfer function, Strehl ratio, and optical quality assessment (OQAS) values. Contrast sensitivity, subjective patient satisfaction, visual acuity, tomography, pachymetry, endothelial cell count, and refraction status were also analyzed.

RESULTS

Objective and subjective visual quality variables had similar results among UT-DSAEK and DMEK procedures. Statistically significant differences favoring DMEK against UT-DSAEK were found in endothelial cell density (658.80 ± 139.33 and 1059.00 ± 421.84 cells/mm², respectively), pachymetry (621.20 ± 33.74 and 529.70 ± 30.00 µm, respectively), and follow-up (45.50 ± 24.76 and 15.50 ± 8.43 months, respectively).

CONCLUSIONS

UT-DSAEK and DMEK revealed no differences in terms of objective and subjective visual quality. However, DMEK showed a faster recovery during the follow-up, increased endothelial cell density, lower pachymetry, and a more anatomical posterior keratometry against UT-DSAEK in this case series paired-eye study.

Four-Year Survival of Descemet Membrane Endothelial Keratoplasty in Patients With Previous Glaucoma Surgery

PURPOSE

To evaluate 4-year outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with previous glaucoma surgery.

DESIGN

Retrospective, comparative case series.

METHODS

Patients with previous trabeculectomy or glaucoma drainage device (GDD) implantation who later underwent DMEK (study group) were matched for follow-up duration with Fuchs dystrophy DMEK patients (control group). The minimum follow-up was 18 months. Primary outcomes included graft survival and rejection rates, and secondary outcomes included rates of detachment/rebubble, endothelial cell loss, best spectacle-corrected visual acuity, intraocular pressure, and glaucoma medications/surgeries. Subgroup analysis compared eyes with and without a GDD.

RESULTS

Ninety-four eyes of 91 patients were included. There were 51 eyes of 49 patients in the study group (GDD = 32 eyes, no GDD = 19 eyes) and 43 eyes of 42 patients in the control group. The mean follow-up was 37.9 ± 15.2 and 33.8 ± 13.5 months, respectively (P = .322). Graft survival probability of the study group at 12, 24, 36, and 48 months was 75%, 60%, 43%, and 27%, respectively, compared with a consistent 88% in the control group (P < .001). Survival curves of study subgroups (GDD and no GDD) were significantly lower than the control group (P < .001). Rejection rates in the study and control groups were 19.6% and 2.3%, respectively (P = .010). Endothelial cell loss in the study group was 12%-22% higher than the control group at 12, 24, 36, and 48 months (P = .049, P = .027, P = .200, and P = .004).

CONCLUSIONS

In eyes with previous glaucoma surgery, DMEK has good early outcomes, but longer-term rejection and failure rates are high. Physicians and patients should be cognizant of the high likelihood of graft failure in this setting.

Surgery for glaucoma in modern corneal graft procedures

Glaucoma is a common cause of vision loss after corneal transplantion and is considered a major risk factor for graft failure. Glaucoma may be present before corneal transplant surgery, or increased intraocular pressure may develop after keratoplasty in up to one-third of patients. Pre-existing glaucoma should be controlled before keratoplasty, either medically or surgically. For postkeratoplasty increase in intraocular pressure; identifying the risk factors allows appropiate follow-up and management. Patients undergoing anterior lamellar keratoplasty may take advantage of reduced rates of postkeratoplasty glaucoma. Glaucoma also complicates eyes with endothelial keratoplasties, mostly related to management of intraocular pressure spikes derived from anterior chamber air bubbles. Nevertheless, the severity is less, and the intraocular pressure is more easily controlled when compared with penetrating keratoplasty. Adequate management of glaucoma that develops before or after keratoplasty may save eyes from irreversible damage to the optic nerve and increase graft survival.

Descemet membrane endothelial keratoplasty in patients with prior glaucoma surgery

OBJECTIVE

To present outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes with prior trabeculectomy or a glaucoma drainage device (GDD).

METHODS

A retrospective case series, including patients that had previously undergone trabeculectomy and/or GDD implantation, who later underwent DMEK between 2013 and 2016 at Toronto Western Hospital and the Kensington Eye Institute. Outcome measures: best spectacle-corrected visual acuity (BSCVA), endothelial cell (EC) density, intraoperative and postoperative complications.

RESULTS

Twenty-seven eyes of 27 patients were included. All DMEK procedures were uneventful. Mean follow-up time was 14.6 ± 6.1 months. In eyes with no visually limiting comorbidities (n = 16), BSCVA improved from 1.34 ± 0.65 logMAR (Snellen equivalent ~20/440) preoperatively to 0.51 ± 0.24 logMAR (Snellen equivalent ~20/65) and 0.50 ± 0.33 logMAR (Snellen equivalent ~20/65) at 6 and 12 months, respectively (p < 0.001 for both). In eyes with visually limiting comorbidities (n = 11), BSCVA improved from 1.92 ± 0.72 logMAR (Snellen equivalent ~20/1665) preoperatively to 1.43 ± 0.83 logMAR (Snellen equivalent ~20/540) and 1.37 ± 0.99 logMAR (Snellen equivalent ~20/470) at 6 and 12 months, respectively (p = 0.008 and p = 0.037).Graft detachment rate was 24.1% and rebubble rate was 17.2%. Primary and secondary graft failure rates were 3.7% and 10.3%, respectively. Rejection rate was 17.2%. EC-loss rate at 6 months and 12 months was 36.7% and 50.5%, respectively.

CONCLUSIONS

DMEK performed in eyes with previous trabeculectomy or a GDD is more challenging than conventional DMEK, but has good outcomes. Higher rates of graft rejection and secondary graft failure in this setting should be further evaluated in long-term studies.

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

Background

To compare the visual outcome and patients’ satisfaction after ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) performed on fellow eyes of the same patients.

Methods

In this retrospective study, the records of 18 pseudophakic patients affected by Fuchs endothelial dystrophy who underwent DMEK in one eye and UT-DSAEK in the fellow eye were reviewed. Best corrected visual acuity (BCVA), corneal pachymetry, keratometry, corneal aberrations, photopic and mesopic contrast sensitivity, and endothelial cell counts measured 12 months after surgery in either eye were analyzed and compared. The results of a satisfaction questionnaire were also reviewed.

Results

Twelve months after surgery, BCVA was not significantly different in UT-DSAEK and DMEK eyes (0.10 ± 0.04 and 0.07 ± 0.07 logMAR, respectively); at both 4- and 6 mm optical zones total and posterior corneal higher order aberrations (HOAs), posterior astigmatism and total coma were significantly lower after DMEK; BCVA in both groups was significantly correlated mainly with anterior corneal aberrations; contrast sensitivity was higher after DMEK especially in mesopic conditions and at medium spatial frequencies; the endothelial cell density was similar, although slightly higher in the UT-DSAEK group (p = 0.10). The satisfaction questionnaire showed that although patients were highly satisfied from both procedures, more than half of them preferred DMEK and reported a more comfortable and quicker postoperative recovery.

Conclusions

DMEK and UT-DSAEK showed no evidence of difference in terms of postoperative BCVA, although DMEK had a better performance in terms of contrast sensitivity, posterior corneal aberrations and overall patient satisfaction.

Descemet Membrane Endothelial Keratoplasty Versus Descemet Stripping Automated Endothelial Keratoplasty and Penetrating Keratoplasty

PURPOSE

To compare the long-term graft survival outcomes and complications of patients who underwent Descemet membrane endothelial keratoplasty (DMEK), Descemet stripping automated endothelial keratoplasty (DSAEK), and penetrating keratoplasty (PK) for Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK).

DESIGN

Retrospective comparative cohort study.

METHODS

Patients with FECD and BK who underwent DMEK (121 eyes), DSAEK (423 eyes), or PK (405 eyes) from the prospective cohort from the Singapore Corneal Transplant Registry were included. A Kaplan-Meier survival analysis was conducted to compare the survival probabilities of the 3 groups. The main outcome measure was graft survival.

RESULTS

The DMEK group had the best overall cumulative graft survival of 97.4%, compared to DSAEK (78.4%) and PK (54.6%) (P < .001). In eyes with FECD, the DMEK group had the best graft survival of 98.7% compared to DSAEK (96.2%) and PK (73.5%) (P = .009). The graft survival in eyes with BK was poorer overall; however, the DMEK group still had the best graft survival of 94.7%, compared to DSAEK (65.1%) and PK (47.0%, P = .001). Eyes that underwent DMEK had the lowest rate of graft rejection (1.7% vs DSAEK 5.0% vs PK 14.1%, P < .001) and postoperative elevation of intraocular pressure (11.6% vs DSAEK 23.6% vs PK 22.5%, P = .015).

CONCLUSIONS

Patients who underwent DMEK for FECD and BK had better graft survival compared to DSAEK and PK. Eyes that underwent DMEK also had a significantly lower rate of graft rejection and elevated intraocular pressure compared to DSAEK and PK for the same indications.

Favourable outcome after late reorientation of an upside-down Descemet Membrane Endothelial Keratoplasty (DMEK) graft: a case report

Background

Clinical outcome after successful reorientation of an upside-down implanted DMEK (Descemet Membrane Endothelial Keratoplasty) graft 4 weeks after initial transplantation.

Case presentation

A 71-year-old woman presented with Fuchs’ endothelial corneal dystrophy for DMEK. After initial DMEK the donor graft was fully attached and well centred during intracameral gas filling. When the gas bubble was fully resorbed the graft started to detach. Therefore, two intracameral gas injections were consecutively performed. During the second re-bubbling, an upside-down orientation was observed and so the graft was flipped, centred, re-attached and finally stabilized by an intracameral gas bubble. Three weeks after reorientation slit lamp examinations showed a well centred and attached graft, endothelial cells that started functioning and a patient’s visual acuity of 20/40. Visual acuity increased to a 20/32 vision in the observed eye three months later and further improved to 20/20 6 months after reorientation and stayed stable between 20/32 and 20/20 during the remaining 15 months of follow-up, with a clear and well-attached graft.

Conclusion

Reorientation of an upside down DMEK graft was successful even 4 weeks after initial DMEK. Visual recovery and endothelial cell count increase were stepwise noticed during the first 6 months and 15 months after reorientation, respectively. Finally a favourable outcome with 20/32 to 20/20 vision at least 6 months after graft reorientation was achieved. Therefore, restoring full graft function could last several weeks or even months following (late) reorientation of an upside-down DMEK graft.

Three-Year Outcome Comparison Between Femtosecond Laser-Assisted and Manual Descemet Membrane Endothelial Keratoplasty

PURPOSE

To evaluate 3-year outcomes of femtosecond laser-assisted Descemet membrane endothelial keratoplasty (F-DMEK) compared with manual Descemet membrane endothelial keratoplasty (M-DMEK) in patients with Fuchs endothelial corneal dystrophy (FECD).

METHODS

A retrospective, interventional study, including eyes with FECD and cataract that underwent either F-DMEK or M-DMEK combined with cataract extraction at either the Toronto Western Hospital or Kensington Eye Institute, and that had at least 18 months' follow-up was conducted.

EXCLUSION CRITERIA

complicated anterior segments, previous vitrectomy, previous keratoplasty, corneal opacity, or any other visually significant ocular comorbidity.

RESULTS

Included were 16 eyes of 15 patients in the F-DMEK group (average follow-up 33.0 ± 9.0 months) and 45 eyes of 40 patients in the M-DMEK group (average follow-up 32.0 ± 7.0 months). There were no issues with the creation of femtosecond descemetorhexis (in the F-DMEK group)-all descemetorhexis cuts were complete. Best spectacle-corrected visual acuity improvement did not differ significantly between the groups at 1, 2, and 3 years (P = 0.849, P = 0.465 and P = 0.936, respectively). Rates of significant detachment in F-DMEK and M-DMEK were 1 of 16 eyes (6.25%) and 16 of 45 eyes (35.6%) (P = 0.027). Rebubbling rates were 1 of 16 eyes (6.25%) and 15 of 45 eyes (33.3%) (P = 0.047). Cell-loss rates following F-DMEK and M-DMEK were 26.8% and 36.5% at 1 year (P = 0.042), 30.5% and 42.3% at 2 years (P = 0.008), 37% and 47.5% at 3 years (P = 0.057), respectively. Graft failure rate was 0% in F-DMEK and 8.9% in M-DMEK (all were primary failures; P = 0.565).

CONCLUSIONS

F-DMEK showed good efficacy with reduced detachment, rebubble, and cell-loss rates, compared with M-DMEK.

Cost-Effectiveness Analysis of Descemet's Membrane Endothelial Keratoplasty Versus Descemet's Stripping Endothelial Keratoplasty in the United States

PURPOSE

To determine the cost-effectiveness of Descemet's membrane endothelial keratoplasty (DMEK) compared with Descemet's stripping automated endothelial keratoplasty (DSAEK) in the United States.

DESIGN

Cost-effectiveness analysis in a surgical center in the United States.

PARTICIPANTS

Binocular adult patient undergoing endothelial keratoplasty.

METHODS

A base case of a 70-year-old man undergoing his first endothelial keratoplasty for bilateral Fuchs endothelial dystrophy. The cost-effectiveness of DMEK was compared with DSAEK over a 15-year time horizon. The incidences and costs of complications were derived from PubMed English literature searches, Medicare reimbursements, and average wholesale prices. All costs were discounted 3% per annum and adjusted for inflation to 2018 U.S. dollars. Uncertainty was evaluated using deterministic and probabilistic sensitivity analyses.

MAIN OUTCOME MEASURES

Incremental cost-effectiveness ratios and incremental cost-utility ratios, measured in cost per quality-adjusted life-years (QALYs).

RESULTS

Performing a DMEK instead of a DSAEK generated an extra 0.4 QALYs over a 15-year period. From a societal and third-party payer perspective, DMEK was cost-saving when compared with DSAEK in improving visual acuity in the base case. Probabilistic sensitivity analyses with variations in the costs and rebubble rates revealed that DMEK was cost-saving compared with DSAEK in 38% of iterations and was within a societal willingness-to-pay threshold of $50 000 in 98% of models.

CONCLUSIONS

From the societal and third-party payer perspectives in the United States, DMEK generated greater utilities and was less costly than DSAEK. Therefore, DMEK was the dominant procedure and was cost-saving with respect to DSAEK. The economic model was robust based on sensitivity analyses.

Descemet's membrane endothelial keratoplasty (DMEK) versus Descemet's stripping automated endothelial keratoplasty (DSAEK) for corneal endothelial failure

BACKGROUND

Corneal endothelial transplantation has become the gold standard for the treatment of corneal endothelial dysfunctions, replacing full thickness transplantation, known as penetrating keratoplasty. Corneal endothelial transplantation has been described using two different techniques: Descemet's membrane endothelial keratoplasty (DMEK) and Descemet's stripping automated endothelial keratoplasty (DSAEK). Both are still performed worldwide.

OBJECTIVES

To compare the effectiveness and safety of Descemet's membrane endothelial keratoplasty (DMEK) versus Descemet's stripping automated endothelial keratoplasty (DSAEK) for the treatment of corneal endothelial failure in people with Fuch's endothelial dystropy (FED) and pseudophakic bullous keratopathy (PBK).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 7); MEDLINE Ovid; Embase Ovid; LILACS BIREME; the ISRCTN registry; ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). The date of the search was 11 August 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and non-randomised paired, contralateral-eye studies in any setting where DMEK was compared with DSAEK to treat people with corneal endothelial failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, assessed trial quality and extracted data using the standard methodological procedures expected by Cochrane. Our primary outcome was best corrected visual acuity (BCVA) measured in logarithm of the Minimum Angle of Resolution (logMAR). Secondary outcomes were endothelial cell count, graft rejection, primary graft failure and graft dislocation. We graded the risk of bias of non-randomised studies (NRSs) using ROBINS-I.

MAIN RESULTS

We did not identify any RCTs but found four non-randomised studies (NRSs) including 72 participants (144 eyes), who had received DSAEK in the first eye followed by DMEK in the fellow eye. All the studies included adult participants where there was evidence of FED and endothelial failure requiring a corneal transplant for the treatment of visual impairment. We did not find any studies that included PBK. The trials were published between 2011 and 2015, and we assessed them as high risk of bias due to potential unknown confounding factors since DSAEK preceded DMEK in all participants. Two studies reported results at 12 months, one at 6 months, and one between 6 and 24 months. At one year, using DMEK in cases of endothelial failure may result in better BCVA compared with DSAEK (mean difference (MD) -0.14, 95% confidence interval (CI) -0.18 to -0.10 logMAR, 4 studies, 140 eyes, low-certainty evidence). None of the participants had severe visual loss (BCVA of 1.0 logMAR or more; very low-certainty evidence). Regarding endothelial cell count data (4 studies, 134 eyes) it is hard to draw any conclusions since two studies suggested no difference and the other two reported that DMEK provides a higher cell density at one year (very low-certainty evidence). No primary graft failure and only one graft rejection were recorded over four studies (144 eyes) (very low-certainty evidence). The most common complications reported were graft dislocations, which were recorded in one or two out of 100 participants with DSAEK but were more common using DMEK, although this difference could not be precisely estimated (risk ratio (RR) 5.40, 95% CI 1.51 to 19.3; 4 studies, 144 eyes, very low-certainty evidence).

AUTHORS' CONCLUSIONS

This review included studies conducted on people with corneal endothelium failure due to FED for whom both DMEK and DSAEK can be considered, and found low-certainty evidence that DMEK provides some advantage in terms of final BCVA, at the cost of more graft dislocations needing 're-bubbling' (very low-certainty of evidence).

Scheimpflug Densitometry After DMEK Versus DSAEK-Two-Year Outcomes

PURPOSE

To compare the course of Scheimpflug corneal densitometry (CD) after Descemet membrane endothelial keratoplasty (DMEK) versus Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

Fifty-four DMEK and 25 DSAEK cases without previous corneal surgery, complicated intraoperative or postoperative course, or vision-limiting ocular comorbidities were included. Pseudophakic eyes of age-matched subjects were recruited as controls (n = 20). Scheimpflug CD of the optically relevant zones (0-2 and 2-6 mm), best-corrected visual acuity (BCVA), endothelial cell density, and central corneal thickness were evaluated preoperatively and at 3, 6, 12, and 24 months postoperatively.

RESULTS

CD of the optical zone decreased from 34.4 ± 9.4 grayscale units (GSU) before to 19.2 ± 2.7 GSU at 24 months after DMEK. Respectively, CD decreased from 34.0 ± 13.4 GSU before to 21.2 ± 2.5 GSU at 24 months after DSAEK. Mean central CD in group 3 was 18.1 ± 1.3 GSU. Compared with DSAEK, DMEK cases showed lower central CD at 3 and 6 months (P ≤ 0.012) but not at 12 and 24 months postoperatively. DSAEK showed higher CD values throughout the postoperative period compared with healthy controls (P < 0.001). DMEK showed higher CD compared with controls at 3, 6, and 12 but not at 24 months after surgery (P = 0.152). Postoperative BCVA was significantly better after DMEK for every examination time point. No difference in endothelial cell density was found between DMEK and DSAEK at any time point.

CONCLUSIONS

DMEK showed lower CD and better BCVA compared with DSAEK in the first 6 postoperative months. Notably, although CD reached similar levels in the midterm after both DMEK and DSAEK, BCVA remained significantly better after DMEK.

Incidence of Cystoid Macular Edema After Descemet Membrane Endothelial Keratoplasty

Purpose:

The incidence of and risk factors for cystoid macular edema (CME) after Descemet membrane endothelial keratoplasty (DMEK) remain uncertain. This study examines the incidence of and risk factors for CME after DMEK.

Methods:

This retrospective, single-center study included patients with no history of CME who had undergone DMEK. Patients were examined weekly for 1 month after surgery and at 3 and 6 months after surgery. Follow-up examinations included visual acuity (VA) assessment, pachymetry, anterior segment optical coherence tomography, biomicroscopy, intraocular pressure measurement, and fundoscopy. Eyes suspected of having CME (reduced VA and/or abnormal fundoscopic findings) underwent macular optical coherence tomography. Potential risk factors for CME examined included age, axial length, anterior chamber rebubbling, not using a topical nonsteroidal antiinflammatory after surgery, and concurrent DMEK and cataract surgery (triple-DMEK).

Results:

Eighty eyes (74 subjects) were included. Eleven eyes (13.8%) developed CME within 6 months after undergoing DMEK. Univariate analyses did not identify any significant CME risk factors. Interestingly, the triple-DMEK procedure did not put subjects at risk for developing CME (P = 0.184). Visual prognosis after medical treatment for CME was excellent, and subjects with and without CME had comparable VA at 6 months [CME: logarithm of the minimum angle of resolution (logMAR) VA = 0.3 (first–third quartile: 0.1–1.0), 20/40; no CME: logMAR VA = 0.3 (0.1–0.5), 20/40; P = 0.391].

Conclusions:

Although CME frequently occurred after DMEK, no CME risk factors were identified. In addition, CME did not significantly affect long-term visual outcomes when it was appropriately treated.