Descemet Membrane Endothelial Keratoplasty: Safety and Outcomes: A Report by the American Academy of Ophthalmology

Techniques, Outcomes, and Complications of Preloaded, Trifolded Descemet Membrane Endothelial Keratoplasty Using the DMEK EndoGlide

PURPOSE

To describe 2 insertion techniques, outcomes, and complications of preloaded, trifolded Descemet membrane endothelial keratoplasty (DMEK) cases using the DMEK EndoGlide inserter.

METHODS

This retrospective, consecutive case series analyzed the first 35 cases using the DMEK EndoGlide performed between October 2018 and October 2019 at a single center. Preloaded, trifolded DMEK tissues were delivered through a fluid-injected or pull-through technique. To inject the tissue, a burst of fluid was delivered into the lumen of the injector with a second instrument. Postoperatively, best-spectacle corrected visual acuity (BSCVA), pachymetry, graft survival, and complications were assessed.

RESULTS

Thirty-five eyes of 29 patients underwent DMEK alone (n = 11), with cataract surgery (n = 21), or with additional surgeries (n = 3). Of these, 19 (54.3%) grafts were injected. Video analysis revealed a median time of 3.5 minutes from graft insertion to opening for gas insertion. Median preoperative BSCVA of 0.398 logMAR improved to 0.097 logMAR (P = 0.02) at 9 months. Median pachymetry decreased from 619 μm to 551 μm (P = 0.03) at 9 months. Median donor endothelial cell count of 2890.5 cells/mm2 reduced to 2123 cells/mm2 (26.6% endothelial cell loss; P = 0.008) 6 months postoperatively. One (2.9%) graft failed due to inverted marking at the eye bank and subsequent reverse implantation.

CONCLUSIONS

Pre-loaded, tri-folded tissues can be implanted with acceptable levels of endothelial cell loss. We describe a no-touch method of injecting pre-loaded, tri-folded tissue and highlight incorrect marking as a potential complication. This may not be identifiable intraoperatively due to lack of scroll formation.

Descemet Membrane Endothelial Keratoplasty Outcomes between Young and Old Graft Recipients

Purpose: To evaluated Descemet's membrane endothelial keratoplasty (DMEK) outcomes in young and old graft recipients.Materials and Methods: Data of 164 surgeries with a median age of 76 years (interquartile range 14 years) undergoing DMEK surgery between 2016 and 2018 was reviewed. Complications, graft survival, and visual acuity gain were compared between subjects in the 25th percentile (young recipients; aged 70 years and less, n = 21) and 75th percentile (old recipients; aged 85 years and over, n = 27) over the 2-year follow-up.Results: Young recipients had a lower rate of pre-operative glaucoma (14.3% vs. 51.9%, p = .014) and pseudophakic bullous keratopathy (9.5% vs. 59.3%, p < .001), and a higher rate of Fuchs endothelial dystrophy (57.1% vs. 14.8%, p = .002) and combined cataract extraction at the time of DMEK surgery (52.4% vs. 7.4%, p = .001) when compared to old recipients. Complications (primary graft failure, pupillary block, cystoid macular edema or infectious keratitis) were independent of graft recipient age. Descemet's membrane detachment requiring re-bubbling was observed more often in young compared to the old recipients (42.9% vs. 14.8%, p = .049). Visual acuity gain between the groups remained comparable up to 1-year, whereas at 2-years old recipients showed significantly declined visual acuity gains compared to the young recipients (0.14 ± 0.68 vs. 0.74 ± 0.49, p = .012). Graft recipients aged over 85 years had a considerably higher graft failure rate over the 24-months (40.7% vs. 4.8%, p = .006) and shorter graft survival time (p = .002; log-rank) when compared to the recipients aged under 70 years. After adjusting for potential confounders such as Fuchs endothelial dystrophy, pseudophakic bullous keratopathy and glaucoma, the recipients aged over 85 remained at higher risk for graft failure (HR = 17.278, 95% CI = 1.787-167.1, p = .014).Conclusions: In aged DMEK recipients, regardless of the low incidence of early postoperative complications, the rate of postoperative graft failure was significantly higher and graft survival shorter than in younger recipients.

Analysis of Immune Cells on Donor Corneal Endothelium After Corneal Transplantation Using the HRT-Rostock Cornea Module

PURPOSE

The aim of this study was to investigate the immune cells on corneal endothelium of the graft in patients who underwent penetrating keratoplasty (PK), Descemet-stripping endothelial keratoplasty (DSEK), and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

A total of 43 eyes of 43 patients who underwent PK (17 eyes), DSEK (13 eyes), and DMEK (13 eyes) and who did not show any sign of graft rejection were recruited for the study. Patients who underwent cataract surgery (26 eyes) served as controls. Immune cells on the corneal endothelium were examined with laser in vivo confocal microscopy. The associations between the corneal endothelial cell density, type of keratoplasty, aqueous flare, repeated keratoplasty, and time after surgery versus the density of immune cells were investigated.

RESULTS

In vivo confocal microscopy visualized similar numbers of immune cells on the corneal endothelium in the PK, DSEK, and DMEK groups, whereas no immune cells were observed in any of the control patients. The numbers of immune cells tended to be higher in regraft eyes in the PK group (P = 0.00221) and in the DSEK group (P = 0.168) than those in the primary graft eyes. No significant association was found between the density of immune cells and corneal endothelial cell density in the PK, DSEK, and DMEK groups.

CONCLUSIONS

Immune cells were observed to a similar extent in the eyes of PK, DSEK, and DMEK subjects even in the absence of any clinical sign of immune rejection. A further prospective longitudinal study will evaluate the effect of immune cells on long-term graft survival and the risk for graft rejection.

Predicting Edema Resolution After Descemet Membrane Endothelial Keratoplasty for Fuchs Dystrophy Using Scheimpflug Tomography

Importance

Predicting the extent of corneal edema resolution after Descemet membrane endothelial keratoplasty (DMEK) may help in preoperative decision-making by identifying patients who may benefit from restoring endothelial function.

Objective

To develop and validate a predictive model for edema resolution after DMEK using Scheimpflug tomographic imaging.

Design, Setting, and Participants

Two prospective studies recruited participants with advanced Fuchs dystrophy at a university-based tertiary referral center between July 1, 2017, and August 31, 2019. Analyses were designed in November 2019 and completed on June 30, 2020. Development of a predictive model using linear least absolute shrinkage and selection operator regression was conducted in a derivation cohort (100 eyes). Overall performance, discrimination, and calibration were tested in the separate validation cohort (32 eyes).

Exposures

Preoperative Scheimpflug parameters and patient-reported visual disability were considered as potential predictors of edema resolution: (1) tomographic features (irregularity of lines of equal corneal thickness, displacement of the thinnest point of corneal thickness from the inferior-temporal quadrant, and absolute amount of focal posterior corneal depression), (2) standardized anterior and posterior corneal backscatter, (3) preoperative central corneal thickness, and (4) Fuchs dystrophy-specific visual disability.

Main Outcomes and Measures

Decrease in central corneal thickness after DMEK indicative of edema resolution.

Results

Of the 88 patients included in the analysis, 54 were women (61%); median age was 68 years (interquartile range [IQR], 59-76 years). A median of 13 months after DMEK (IQR, 9-16 months), median corneal thickness was 77 μm lower (IQR, 51-94 μm) in the derivation cohort and 75 μm lower in the validation cohort (IQR, 54-96 μm) than before surgery. Per 10-μm edema resolution, eyes gained 0.66 Early Treatment Diabetic Retinopathy Study letters (95% CI, 0.09-1.23) in best-corrected visual acuity. Three tomographic features were present in 68 of 100 eyes (68%) in the derivation cohort and in 18 of 32 eyes (56%) in the validation cohort before DMEK and in only 1 of 132 eyes (1%) after DMEK. To predict edema resolution after DMEK based on preoperative assessment, 5 variables were selected by the statistical learning algorithm: nonparallel isopachs, focal posterior depression, anterior and posterior corneal backscatter, and central corneal thickness. In the separate validation cohort, the model showed high overall performance, discrimination, and calibration.

Conclusions and Relevance

These post hoc analyses of prospective cohorts support a model for use in the prediction of edema resolution after DMEK using Scheimpflug measurement to identify patients benefitting most from DMEK.

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 Congenital Hereditary Endothelial Dystrophy: Initial Experiences

PURPOSE

To report our early experiences with Descemet membrane endothelial keratoplasty (DMEK) in congenital hereditary endothelial dystrophy (CHED).

METHODS

Retrospective analysis of medical records of eyes with CHED that underwent DMEK between January 1, 2018, and April 30, 2019, and had a minimum of 1-year follow-up.

RESULTS

Three eyes of 2 CHED patients (a 10-year-old girl and a 22-year-old man) were included. Both had decreased vision and hazy corneas from birth and underwent DMEK during the study period. Surgery was performed by a single surgeon and was uneventful in all 3 eyes. Within 1 month of surgery, the corneal edema cleared, and vision improved significantly. The mean decimal visual acuity improved from 0.15 ± 0.08 (baseline) to 0.33 ± 0.19 at 3 months. The mean central corneal thickness improved from 928 ± 2.3 μm (baseline) to 555.3 ± 25.8 μm at 3 months. The final visual outcome was less in 1 eye because of dense amblyopia. In all 3 eyes, a subtle stromal haze persisted even after resolution of edema. One eye had graft rejection 7 months after surgery because of discontinuation of medications, effectively managed by increasing the frequency of topical steroids.

CONCLUSIONS

DMEK may be a viable option in phakic eyes with CHED.

A Novel Technique for Donor Insertion and Unfolding in Descemet Membrane Endothelial Keratoplasty

PURPOSE

To describe a novel technique for insertion and unfolding of donor Descemet membrane (DM) scroll during DM endothelial keratoplasty (DMEK).

METHODS

DMEK was performed in 20 eyes. The donor DM scroll was loaded into a glass injector, and the fluid column was manipulated to achieve a double scroll configuration. After performing DM stripping and inferior iridectomy, an anterior chamber (AC) maintainer was placed in position. The glass injector was inserted into the AC and the tip rotated to ensure correct orientation of the DM scroll. After disconnecting the IV tubing from the AC maintainer, the donor DM scroll was delivered into the AC. Donor unfolding was performed using surface tapping techniques. An air bubble was injected under the graft to obtain a complete AC air fill. The outcomes of this surgical technique were analyzed.

RESULTS

Donor DM insertion and unfolding were performed without any complications in all eyes. Double scroll configuration of donor DM in the injector could be achieved in 17 of 20 eyes (85%). A controlled delivery, maintaining correct scroll orientation, was possible in all eyes. Intraoperative duration from insertion to unfolding was 252.7 ± 45.4 seconds. A clear cornea was achieved in all eyes, with 75% of eyes (15/20) achieving corrected distance visual acuity of 20/20 or better, at average follow-up duration of 13.3 ± 1.3 months. Endothelial cell loss at 6 months follow-up was noted to be 16.7%. Partial donor detachment was noted in 2 eyes (10%), which resolved spontaneously.

CONCLUSIONS

Our novel technique of donor DM insertion allows easy donor insertion and unfolding, thereby simplifying the DMEK procedure.

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 With a Pull-Through Insertion Device: Surgical Technique, Endothelial Cell Loss, and Early Clinical Results

PURPOSE

To describe a surgical technique for Descemet membrane endothelial keratoplasty (DMEK) using a pull-through, endothelium-in insertion device, the DMEK EndoGlide. We evaluated the endothelial cell loss (ECL) associated with the EndoGlide-DMEK (E-DMEK) technique in both ex vivo and prospective clinical studies.

METHODS

The ex vivo study involved calcein acetoxymethyl staining and preparation of DMEK grafts, which were trifolded endothelium-in, loaded into the EndoGlide, pulled through, and unfolded in imaging dishes. Inverted fluorescent microscopy was performed, and ECL was quantified using trainable segmentation software. The prospective clinical series describes the outcomes of consecutive surgeries using the E-DMEK technique. Grafts were pulled through the EndoGlide with forceps and unfolded in the anterior chamber endothelium-down. Our main outcome measure was ECL in both studies.

RESULTS

In the ex vivo study with 9 human donor corneas, mean ECL was 15.2% ± 5.4% (n = 9). In our clinical series of 69 eyes, leading indications for surgery were pseudophakic/aphakic bullous keratopathy (47.8%), previous failed grafts (23.2%), and Fuchs endothelial dystrophy (18.8%). Rebubbling and primary graft failure rates related to E-DMEK were 11.6% and 1.5%, respectively. Among eyes with at least 6 months of follow-up, mean preoperative endothelial cell density was 2772 (range 2457-3448) cells/mm, and postoperative endothelial cell density was 1830 (range 541-2545) cells/mm. Mean ECL was 33.6% (range 7.5-80.4; n = 32) at the 7.1 (range 6-11) months follow-up.

CONCLUSIONS

The ex vivo and pilot clinical studies suggest that E-DMEK shows acceptable rates of ECL, with safe and promising early clinical outcomes.

Real-World Outcomes of DMEK: A Prospective Dutch registry study

PURPOSE

This study analyzed real-world practice patterns, graft survival, and outcomes of Descemet membrane endothelial keratoplasty (DMEK) in the Netherlands.

DESIGN

Population-based interventional clinical study.

METHODS

In this prospective registry study, all consecutive primary DMEK procedures registered in the Netherlands Organ Transplant Registry were identified. Short-term graft survival and outcomes of primary transplants for Fuchs' endothelial dystrophy (FED) were analyzed using Kaplan-Meier survival curves with log-rank test and Cox regression. Linear mixed model analyses were used for best spectacle-corrected visual acuity (BSCVA), spherical equivalent, hyperopic shift, and endothelial cell density.

RESULTS

752 DMEKs were identified between 2011 and 2018. In 90% of cases, the indication for DMEK was FED. Graft survival measured 87% at 3 months, 85% at 6 months, 85% at 1 year, and 78% at 2 years. DMEK procedures after 2015 showed better survival compared to previous years (Hazard ratio = 0.4; P < .001). Baseline BSCVA in primary transplants with FED measured on average 0.45 logarithm of the minimum angle of resolution (logMAR) (95% confidence interval [CI], 0.41-0.49), and significantly improved (overall P < .001) to 0.17 logMAR (95% CI, 0.14-0.21) at 3 months, 0.15 logMAR (95% CI, 0.11-0.18) at 6 months, 0.12 logMAR (95% CI, 0.08-0.16) at 1 year, and 0.08 (95% CI, 0.05-0.12) at 2 years. At 3 months, a hyperopic shift of +0.36 diopters (P < .001) was observed and endothelial cell loss measured 33%.

CONCLUSION

Our findings provide real-world support that DMEK is an effective treatment for FED with respect to vision restoration, inducing a small hyperopic shift with an acceptable endothelial cell loss. Graft survival improved over time, suggesting a learning curve on a national level.

Laser-assisted corneal transplantation surgery

Corneal transplant surgeries have a broad range of indications with outcomes largely dependent on surgeon experience. Traditional manual techniques have certain limitations pertaining to the preparation of donor tissue and the recipient bed that might affect the predictability of visual outcomes. Use of lasers for keratoplasty procedures not only improves the repeatability and consistency of the technique, but also enables the surgeon to control the thickness and shape of the transplant tissue tailored to the specific condition. Despite the advantages, cost-effectiveness and technical know-how remain the major challenges. We discuss the various techniques of laser-assisted keratoplasties with respect to their methods, precision, and efficacy in various corneal indications.

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.

Refractive accuracy in eyes undergoing combined cataract extraction and Descemet membrane endothelial keratoplasty

PURPOSE

To evaluate the refractive accuracy of current intraocular lens (IOL) formulas and propose a modification in calculation of corneal power in eyes undergoing combined cataract extraction and Descemet membrane endothelial keratoplasty (DMEK).

DESIGN

Retrospective cohort study.

METHODS

Patients with Fuchs endothelial corneal dystrophy undergoing uncomplicated combined cataract surgery and DMEK at a single institution were included. The Hoffer Q, SRK/T, Holladay I, Barrett Universal II and Haigis formulas were compared. A modified corneal power was calculated using a thick lens equation based on anterior and posterior corneal radii and corneal thickness from Pentacam imaging. Error calculations were adjusted based on the difference in optical biometry and the modified corneal power. Mean absolute error (MAE) for each formula was compared between the corneal power modification and optical biometry corneal power.

RESULTS

In 86 eyes, the mean error ranged from 0.90 D for the Barrett Universal II formula to -0.10 D for the Haigis formula, with 4 of 5 formulas resulting in a mean hyperopic error. The corneal power modification resulted in a significantly lower MAE for the Hoffer Q (0.82 D), Holladay I (0.85 D), SRK/T (0.85 D) and Barrett Universal II (0.90 D) formulas compared with optical biometry corneal power for the Hoffer Q (1.02 D; p<0.005), Holladay I (0.97 D; p<0.005), SRK/T (0.93 D; p<0.01) and Barrett Universal II (1.16 D; p<0.005) formulas.

CONCLUSIONS

All formulas except the Haigis formula resulted in a hyperopic error. The corneal power modification significantly reduced error in four out of five IOL formulas.

Outcomes of Gel Stent Implantation for Glaucoma in Patients With Previous Corneal Graft Surgery: A Case Series

PURPOSE

To report a series of 5 cases with successful placement of a minimally invasive glaucoma surgery (MIGS) device for glaucoma refractory to medical management in patients with previous corneal grafts.

METHODS

This is a retrospective analysis of all cases with a Xen45 Gel Stent (Allergan plc, Dublin, Ireland) for ocular hypertension and glaucoma refractory to medical treatment after corneal graft surgery between 2016 and 2019 at the Rothschild Foundation, Paris. We did the imaging studies and studied the intraocular pressure (IOP) and the endothelial cell count preimplantation and postimplantation with a MIGS device.

RESULTS

Five cases were included in this study, demonstrating a well-tolerated, highly effective, and sustained method for controlling the IOP, which was refractory to previous treatment. An average IOP reduction of 70.5% was noted with a needling rate of 20%, and no adverse events were noted except 1 IOP spike day 7 post-op with no long-term effects.

CONCLUSIONS

Glaucoma after graft surgery is a well-known and devastating complication, and as numbers of graft surgery performed increases, so will the incidence of glaucoma. MIGS devices such as the Xen45 Gel Stent (Allergan plc) should become a part of our accepted armory to treat raised IOP refractory to medical treatment without delay.

Graft detachments in endothelial keratoplasty

Graft detachment is the most common complication of endothelial keratoplasty. With the ongoing advancements in the field of endothelial keratoplasty, our understanding of risk factors of graft detachments and its management has been evolving. Various prevention measures have been described in literature including presoaking the donor graft, anterior chamber tamponade, venting incisions, sutures to prevent dislocation of graft. Management of a detached graft involves secondary interventions such as rebubbling, suturing and regrafts. In this review, we discuss graft detachment in different types of endothelial keratoplasty techniques including Descemet stripping endothelial keratoplasty, Descemet stripping automated endothelial keratoplasty and Descemet's membrane endothelial keratoplasty; with emphasis on incidence, risk factors, preventive measures and their management.

Risk Factors for Repeat Keratoplasty after Endothelial Keratoplasty in the Medicare Population

PURPOSE

To evaluate long-term rates of repeated keratoplasty after endothelial keratoplasty (EK), and to explore risk factors associated with graft failure.

DESIGN

Retrospective, cohort study.

METHODS

Population-based using 2010-2019 Medicare carrier claims.

STUDY POPULATION

Medicare beneficiaries aged ≥65 years who underwent endothelial keratoplasty (EK) procedures. Main outcome measures were 1) occurrence of repeated keratoplasty for the overall cohort as well as stratified by clinical indication, and 2), risk factors associated with repeated keratoplasty. The probability of undergoing repeated keratoplasty for different indications was estimated using the Kaplan-Meier method and compared using the log-rank test. A Cox proportional hazards regression model was constructed to determine patient and physician factors associated with the risk of repeated keratoplasty.

RESULTS

A total of 94,829 Medicare EK procedures (N = 71,040 unique patients) were included in the analysis. Over the study period, 11,013 of 94,829 EK procedures were followed by repeated keratoplasty. The overall probability of receiving a repeated keratoplasty was 6.1% at 6 months, 7.6% at 1 year, 14.3% at 5 years and 16.9% at 8 years. The probability of repeated keratoplasty was highest for procedures performed for prior failed grafts: 10.2% at 1 year, 29.9% at 8 years. Whereas 6.4% and 11.4% of grafts performed for Fuchs' endothelial dystrophy (FED) required repeated keratoplasty at 1 and 8 years of follow-up, respectively. For bullous keratoplasty and/or corneal edema, 8.6% and 22% of grafts underwent repeated keratoplasty at 1 and 8 years, respectively. In a multivariate analysis, patient factors associated with increased risk of repeated keratoplasty were black (hazard ratio [HR]: 1.29; 95% confidence interval [CI]: 1.20-1.38) or Asians (HR: 1.26; 95% CI: 1.10-1.45) having a glaucoma diagnosis (HR: 1.53; 95% CI: 1.46-1.60), prior glaucoma surgery (HR: 1.26; 95% CI: 1.18-1.35), and concurrent glaucoma surgery (HR: 1.31; 95% CI: 1.20-1.44). Surgeons with higher EK volumes had a decreased risk of repeated keratoplasty. Physicians who graduated medical school >30 years previously had increased risk of repeated keratoplasty compared to those who graduated within 10 years (HR: 1.16; 95% CI: 1.10-1.23).

CONCLUSIONS

Blacks or Asians, comorbid glaucoma, concurrent or prior glaucoma surgery, and lower volumes of surgery are associated with increased risk of repeated keratoplasty. Racial disparities identified in this study warrant further investigation.

Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty in Pseudophakic Eyes Compared With Triple-DMEK at 1-Year Follow-up

PURPOSE

To compare the survival rate 1 year after Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic eyes versus combined phacoemulsification and DMEK (triple-DMEK).

METHODS

Retrospective, interventional, consecutive case series. From all DMEKs performed from January 1, 2017, to June 30, 2018, we selected those performed in pseudophakic eyes (pseudophakic DMEK) and those that underwent triple-DMEK. We compared the survival rate 1 year after surgery between both groups and between the Fuchs endothelial dystrophy (FED) cases in both groups, plus the FED cases versus the pseudophakic bullous keratopathy (PBK) cases in the pseudophakic DMEK group. Second, we compared rebubbling rates and the influence of the use of gas or corneal sutures on rebubbling and dislocation rates.

RESULTS

A total of 329 eyes were included (218 eyes pseudophakic DMEK and 111 eyes triple-DMEK). The survival rate at 1 year was 79.8% and 90%, respectively (P = 0.03). When only FED cases were included (133 pseudophakic DMEK and 108 triple-DMEK), no significant difference was found (87.9% vs. 90.7%, P = 0.59). Within the pseudophakic DMEK group, the survival rate was higher in FED cases (87.8%) compared with PBK cases (66.6%) (P = 0.0001). Rebubbling rates were 21.1% (pseudophakic DMEK) and 17.1% (triple-DMEK) (P = 0.39). The use of gas versus air or placing corneal sutures did not seem to influence the rebubbling (P = 0.64 and P = 0.13, respectively) or dislocation rates (P = 0.71 and P = 0.53, respectively).

CONCLUSIONS

In the FED cases, performing phacoemulsification before DMEK or doing a combined procedure did not seem to affect the rebubbling or survival rate up to 1 year postoperatively. PBK was associated with a higher failure rate compared with that of FED.

A Novel Marking Technique for Descemet Membrane Endothelial Graft Using an Ophthalmic Viscoelastic Device

PURPOSE

To describe the viscoelastic marking technique, a novel marking technique of Descemet membrane endothelial keratoplasty (DMEK) grafts that enables usage of a single donor cornea for 2 surgeries-one that uses Descemet membrane and endothelium (DMEK) and the other using the stroma and Bowman layer.

METHODS

A retrospective case analysis was performed on 26 eyes of 26 consecutive patients who underwent DMEK using the "viscoelastic marking technique." In this novel technique, an ophthalmic viscoelastic device (Healon 5) is placed over the endothelial side. Descemet membrane is then folded in half over the ophthalmic viscoelastic device with the stromal side up, and the F mark is drawn on the stromal side of the folded Descemet membrane. Primary outcome was best spectacle-corrected visual acuity, and secondary outcomes included graft detachment and rebubble rate, graft failure, and endothelial cell density.

RESULTS

Mean best spectacle-corrected visual acuity improved significantly from 1.0 ± 0.7 logarithm of the minimum angle of resolution (LogMAR) before the surgery to 0.9 ± 0.7 LogMAR, 0.5 ± 0.6 LogMAR, 0.4 ± 0.2 LogMAR, and 0.4 ± 0.4 LogMAR at 1, 3, 6, and 12 months after surgery, respectively. Seven eyes (27%) had partial graft detachment that required air injection. Primary failure occurred in 3 eyes (11%). There were no free-floating donors or recognized inverted donors. The endothelial cell density loss at 12 months after surgery was a cell-loss rate of 38.3%.

CONCLUSIONS

The viscoelastic marking technique is a simple, approachable, and safe technique for marking DMEK grafts while preserving the anterior cornea for additional surgery.

Vertical Scrolling Axis of Corneal Endothelial Grafts for Descemet Membrane Endothelial Keratoplasty

PURPOSE

Heterogeneity in scrolling behavior of Descemet membrane endothelial keratoplasty (DMEK) grafts complicates DMEK surgery. This prospective observational study assessed scrolling axes of DMEK grafts relative to the donor's eye.

METHODS

The eye bank randomly marked the rim of corneoscleral donor buttons during trephination and recorded the position relative to the donor's axis. Surgeons were masked to the absolute position of the eye bank marking and recorded the scrolling axis relative to the eye bank marking and DMEK upside-down orientation. The scrolling axis was categorized as vertical (0 to 30 degrees and 150 to 180 degrees), oblique (>30 to 60 degrees and 120 to <150 degrees), and horizontal (>60 to <120 degrees). Scrolling patterns of corneas from the same donor were assessed.

RESULTS

Scrolling patterns of 202 donor corneas from 149 donors were determined. The donor graft scrolled predominantly vertically to the donor's cornea [75%; 95% confidence interval (CI), 68%-80%]. Horizontal axes (11%) and oblique axes (14%) were less common. The median deviation in scrolling axes after unfolding the grafts was 0 degrees from the original scrolling axis (interquartile range, 0-15), indicating that scrolling axes were stable. Fellow eyes of 46 donors had 3.55 times higher odds of a nonvertical scrolling pattern if the first eye had a nonvertical scrolling pattern (95% CI, 1.37-9.20), suggesting that donor factors influencing both eyes could contribute to scrolling patterns.

CONCLUSIONS

DMEK grafts have a natural and stable scrolling tendency at vertical axis of donor's cornea. Anticipating scrolling axes might help improve preparation techniques for DMEK grafts and outcomes.

Outcomes of Descemet's membrane endothelial keratoplasty for congenital hereditary endothelial dystrophy

PURPOSE

To report outcomes of Descemet's membrane endothelial keratoplasty (DMEK) in eyes with congenital hereditary endothelial dystrophy (CHED).

METHODS

The medical records of patients with CHED who underwent DMEK were retrospectively reviewed. Pre- and postoperative visual acuity, corneal thickness, corneal clarity, and graft survival, were analyzed, and intra- and postoperative complications were assessed.

RESULTS

A total of 14 eyes of 8 patients were included. Surgery was performed at a mean age of 10 ± 7 years (range, 2-23). DMEK was successfully performed in all eyes, with 13 of 14 eyes (93%) maintaining a clear cornea at final follow-up (mean, 16.9 ± 8.1 months). Following surgery, corrected distance visual acuity improved from 0.9 ± 0.3 logMAR (Snellen 20/158) to 0.4 ± 0.2 (20/50), and pachymetry improved from 932 ± 57 μm to 642 ± 93 μm. Endothelial cell loss was 33%, and average cell counts were 1767 ± 281 cells/mm² at final follow-up. Intraoperative aqueous misdirection occurred in both eyes of a 2-year-old child, requiring pars plana vitrectomy. Postoperative donor Descemet's membrane detachment occurred in 4 eyes. Rebubbling was performed in 3 eyes (21%); 1 eye had spontaneous reattachment. One eye (8%) had possible graft failure during follow-up, requiring repeat DMEK surgery.

CONCLUSIONS

In our study cohort of eyes with CHED, DMEK was performed with good visual outcome. Rebubbling was necessary for donor reattachment in the early postoperative period in some cases.

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.

Scrolling of the Donor Cornea in Dependence of Temperature and Osmolarity for Descemet Membrane Endothelial Keratoplasty

BACKGROUND

After preparation of a graft for Descemet membrane endothelial keratoplasty (DMEK), the diameter of the graft's scroll varies significantly. In particular, narrow scrolls may complicate DMEK surgery. In this study we investigated how temperature, osmolarity, and deswelling of the donor tissue influence scrolling diameter.

MATERIAL AND METHODS

In this study we examined donor corneas that could not be used for transplantation. The diameter of the DMEK donor scrolls was measured after graft preparation by reflected light microscopy under different conditions: (1) The diameter of the roll was measured in Ringer's solution at temperatures of 5 °C, 24 °C and 35 °C. (2) To study the effect of different culture conditions we used 6% dextran-containing medium for 10 min, 20 min, 16 h and 24 h, and hyper- and hypoosmolar fluids (5% NaCl or aqua dest) for 5 min each.

RESULTS

The median donors age was 62 years. The median endothelial cell density of the donor corneas was 1679 cells/mm². The median diameter of the DMEK scroll was 1.35 mm in Ringer's solution at 24 °C (IQR, 1.04 - 1.89). In Ringer's solution at different temperatures, the scrolling diameter changed between 0.02 mm and 0.29 mm. The change in osmolarity resulted in a difference of 0.02 mm to 0.46 mm. Deswelling with dextran resulted in a change of scrolling diameter between 0.02 mm and 0.09 mm.

SUMMARY

In this experimental case series, the diameter of the DMEK scroll did not change due to changes of temperature, osmolarity or deswelling. Influencing the graft's scroll to standardize and simplify the DMEK surgery remains an interesting goal for future studies.

Impact of Re-bubbling after Descemet Membrane Endothelial Keratoplasty on Long-term Results

Purpose/Aim of the study: Graft detachment after DMEK can be treated easily with an additional air injection - re-bubbling. The aim of our study was to investigate the effect of a re-bubbling on the postoperative outcome.Materials and Methods: In this retrospective, comparative, cohort study we included eyes from patients that underwent DMEK surgery. A graft detachment was diagnosed by slit-lamp examination and OCT scan. All eyes were divided into three groups: no re-bubbling, one re-bubbling, more than one re-bubbling. We analyzed the visual acuity, endothelial cell density and rate of graft failure.Results: In 163 of 463 eyes (35.2%) a re-bubbling was performed (119 eyes 1 re-bubbling, 44 eyes more than one re-bubbling). Visual acuity improved significantly in all groups. After controlling for donor age, reason for surgery, time of cultivation of the graft and preoperative visual acuity, no difference in the visual acuity was seen at any point of follow-up. All patients showed a significant reduction in endothelial cell density 1 month after DMEK. Controlling for donor age, reason for surgery, type of surgery (DMEK-only or DMEK combined with cataract surgery) and the time of cultivation of the graft, the difference in endothelial cell density at 1 month post-surgery between no re-bubbling and one re-bubbling was 157 cells/mm² (95% CI 2-310, p = .047) and between no re-bubbling and more than one re-bubbling 504 cells/mm² (95% CI 267 - 741, p < .001). The difference in endothelial cell density remained over the course of follow-up. Twenty patients (4.3%) developed a graft failure during postoperative follow-up. Controlling for donor age, reason for surgery and the time of cultivation of the graft, we did not find any difference in the risk of graft failure between re-bubbling categories.Conclusions: Re-bubbling increased the risk for an endothelial cell loss, but did not influence the postoperative visual acuity and the rate of graft failure.

Refractive Outcomes After Descemet Membrane Endothelial Keratoplasty + Cataract/Intraocular Lens Triple Procedure: A Fellow Eye Comparison

PURPOSE

Descemet membrane endothelial keratoplasty is often combined with phacoemulsification and intraocular lens implantation (DMEK + cataract/IOL triple procedure) in phakic patients. This procedure results in a refractive shift that is difficult to predict. The aim of this study was to evaluate the hypothesis that the refractive shift in the second eye follows the shift in the first eye.

METHODS

In this retrospective, single-center, consecutive case series, the refractive outcomes of 254 eyes of 127 patients who underwent DMEK + cataract/IOL triple procedure in both eyes for Fuchs endothelial corneal dystrophy have been analyzed. Main outcome measures were spherical equivalent outcome (shift calculations), best spectacle-corrected visual acuity, central corneal thickness, and posterior simulated keratometry.

RESULTS

The mean best spectacle-corrected visual acuity before surgery was 0.51 ± 0.24 and increased to 0.19 ± 0.15 (logMAR) after surgery (P < 0.001). After surgery, a mean hyperopic shift of 0.98 ± 0.89 D was observed. The refractive shift was 1.03 ± 0.93 D and 0.92 ± 1.02 D, in the first and second eyes, respectively (P = 0.435). In a paired analysis, the mean difference of the refractive shift between the first and second eyes was 0.49 ± 0.43 D.

CONCLUSIONS

In our fellow eye comparison, the refractive shift after DMEK + cataract/IOL triple procedure in the second eye was comparable with the shift in the first eye. As a consequence, the refractive outcome of the first eye might serve as a reference for optimizing the refractive target in the second eye. Further studies investigating the influence of corneal parameters on refractive shift are needed for a more predictable lens power selection.

Postoperative Complications in Medicare Beneficiaries Following Endothelial Keratoplasty Surgery

PURPOSE

To determine national-level incidence rates of major postoperative complications following endothelial keratoplasty (EK) procedures and to stratify these rates based on EK indications over an 8-year period using Medicare claims data.

DESIGN

Retrospective, cohort study.

METHODS

Setting: population-based; study population: Medicare beneficiaries aged ≥65 years who underwent EK procedures; main outcome measurements: 1) occurrence of major postoperative complications (i.e., endophthalmitis, choroidal hemorrhage, infectious keratitis, cystoid macular edema [CME], retinal detachment [RD], or RD surgery) following EK surgery; 2) time-to-event analysis for glaucoma surgery; and 3) occurrence of graft complications.

RESULTS

A total of 94,829 EK procedures (n = 71,040 unique patients) were included in the analysis. Of the total, 29% of patients had pre-existing glaucoma. The overall 90-day cumulative incidence of postoperative endophthalmitis and choroidal hemorrhage following EK was 0.03% and 0.05%, respectively. The overall 1-year cumulative rates of RD or RD surgery, infectious keratitis, and CME were 1.0%, 0.8%, and 4.1%, respectively. Approximately 7.6%, 12.2%, and 13.8% of all eyes in this study needed glaucoma surgery at 1-, 5-, and 8-years of follow-up, respectively. The probability of glaucoma surgery among patients with pre-existing glaucoma was 29% vs. 8% among those without pre-existing glaucoma at 8 years. The cumulative probabilities of developing any graft complications were 13%, 23.2%, and 27.1% at 1, 5, and 8 years, respectively, of follow-up. On average, patients undergoing EK procedures for a prior failed graft had the highest rate of complications, whereas those with Fuchs' corneal endothelial dystrophy had the lowest.

CONCLUSIONS

The incidence of major postoperative complications including endophthalmitis, retinal detachment, and choroidal hemorrhage following EK procedures is low. A high proportion of eyes undergoing EK eventually require glaucoma surgery and experience graft-related complications. Postoperative outcomes are typically worse for patients undergoing EK for prior failed grafts than for those undergoing EK for Fuchs' corneal endothelial dystrophy.

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.

Eye bank versus surgeon prepared DMEK tissues: influence on adhesion and re-bubbling rate

Aim

To investigate the difference in adhesion and rebubbling rate between eye bank and surgeon prepared Descemet membrane endothelial keratoplasty (DMEK) tissues.

Methods

Laboratory and clinical retrospective comparative interventional case series. Research corneal tissues were obtained for laboratory investigation. The clinical study involved patients with endothelial dysfunction who underwent DMEK surgery and tamponade with air. Tissues were stripped using a standard DMEK stripping technique (SCUBA) and shipped as prestripped or loaded in a 2.2 intra-ocular lens cartridge with endothelium facing inwards (preloaded) before transporting from the eye bank to the surgeon. For surgeon prepared tissues, all the grafts were stripped in the theatre and transplanted or stripped in the laboratory and tested immediately. Adhesion force and elastic modulus were measured in the centre and mid-periphery in a laboratory ex vivo investigation using atomic force microscopy, while rebubbling rates were recorded in the clinical study.

Results

There was no difference in endothelial cell viability between surgeon or eye bank prepared tissue. Surgeon-stripped DMEK grafts in the laboratory investigation showed significantly higher elastic modulus and adhesion force compared to prestripped and preloaded tissues (p<0.0001). In the clinical data, rebubbling rates of 48%, 40% and 15% were observed in preloaded, prestripped and surgeon-stripped DMEK grafts, respectively. Rebubbling rates were significantly associated with combined cataract surgery (p=0.009) and with time from harvesting the graft to the surgery (p=0.02).

Conclusions

Decreased adhesion forces and elastic modulus in eye bank prepared tissues may contribute to increased rebubbling rates.

Clinical outcomes of pre-loaded ultra-thin DSAEK and pre-loaded DMEK

Objective

To compare clinical outcomes and complications between pre-loaded ultra-thin Descemet stripping automated endothelialkeratoplasty (pl-UT-DSAEK) and pre-loaded Descemet membrane endothelial keratoplasty (pl-DMEK).

Methods and analysis

Comparative study in patients with endothelial dysfunction associated with Fuchs endothelial corneal dystrophy and pseudophakic bullous keratopathy who underwent pl-UT-DSAEK or pl-DMEK transplants. For both groups, the tissues were pre-loaded at the Fondazione Banca degli Occhi del Veneto (Venice, Italy) and shipped to The Royal Liverpool University Hospital (Liverpool, UK). Best corrected visual acuity (BCVA) and re-bubbling rates were the main outcome measures.

Results

56 eyes of 56 patients were included. 31 received pl-UT-DSAEK and 25 received pl-DMEK. At 12 months, BCVA (LogMAR) was significantly better for pl-DMEK (0.17±0.20 LogMAR) compared with pl-UT-DSAEK (0.37±0.37 LogMAR, p<0.01). The percentage of people that achieved ≥20/30 was significantly higher in the pl-DMEK group. The rate of re-bubbling, however, was significantly higher for pl-DMEK (44.0%) than for Pl-UT-DSAEK (12.9%), p<0.01.

Conclusion

Pl-DMEK offers better BCVA than pl-UT-DSAEK. The higher re-bubbling rate associated with pre-loaded DMEK is of concern.

Corneal transplantation after failed grafts: Options and outcomes

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Because of the large number of transplants, corneal graft failure has become one of the most common indications for corneal transplantation. The relatively recently developed lamellar transplant techniques have brought about specific potential complications leading to graft failure that may require different approaches to repeat transplantation other than penetrating keratoplasty. On the other hand, these new lamellar techniques also provide novel ways of rescuing failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as reduced intraoperative risks and faster visual rehabilitation. We summarize the incidence and risk factors of graft failure for penetrating and lamellar (stromal and endothelial) corneal transplants and discuss the various surgical alternatives currently available to rescue such failed grafts, with a focus on the reported outcomes and limitations.

Characteristics of preoperative and postoperative astigmatism in patients having Descemet membrane endothelial keratoplasty

PURPOSE

To evaluate the characteristics of preoperative and postoperative astigmatism in patients having Descemet membrane endothelial keratoplasty (DMEK).

SETTING

Department of Ophthalmology, Goethe University, Frankfurt, Germany.

DESIGN

Retrospective case series.

METHODS

Measurements were obtained using a Scheimpflug camera (Pentacam AXL) preoperatively and 3 months and 12 months postoperatively. Values of front and back astigmatism and total astigmatism in the central 4.0 mm diameter zone (TCA4) were analyzed.

RESULTS

Fifty-three eyes of 45 patients were included. The prevalence of TCA4 above 1.0 diopter (D) was considerably higher (79%) and with-the-rule astigmatism was less frequent in this cohort of European patients with Fuchs endothelial dystrophy (mean age 65 years) than that reported in a meta-analysis of healthy European eyes. The TCA4 values correlated with anterior astigmatism preoperatively and postoperatively (P < .001) and with posterior astigmatism at the 1-year follow-up (P < .01). Although, no correlation was found between the preoperative and 1-year results for anterior astigmatism (P = .12), posterior astigmatism (P = .35), or total corneal astigmatism (P = .47), the difference in vector analysis between the two measurements was only 0.01 at 109 degrees, 0.03 at 98 degrees, and 0.02 at 157 degrees, respectively. However, the greater the difference between the preoperative TCA3 and preoperative TCA5 values, the greater the decrease in corneal astigmatism (P < .001).

CONCLUSIONS

The percentage of eyes with corneal astigmatism above 1.0 D was higher preoperatively and postoperatively in patients with Fuchs endothelial dystrophy than in a healthy population. Predicting postoperative astigmatism based on preoperative results is not possible; however, in eyes with a high difference between TCA3 and TCA5, a reduction in corneal astigmatism after DMEK is likely.

Endothelial Cell Loss After Descemet's Membrane Endothelial Keratoplasty for Fuchs' Endothelial Dystrophy: DMEK Compared to Triple DMEK

PURPOSE

This study compared the outcomes after Descemet's membrane endothelial keratoplasty (DMEK) in pseudophakic patients with the outcomes after DMEK combined with cataract surgery (triple-DMEK) in patients with Fuchs' endothelial dystrophy (FED).

DESIGN

Retrospective, single-institution, interventional, consecutive case series.

METHODS

Outcomes of 114 DMEKs in patients with FED at a minimum of 1-year follow-up were reviewed. A total of 34 eyes (29 patients) were pseudophakic and underwent only DMEK (DMEK-only), and 80 eyes (56 patients) underwent triple-DMEK. Main outcome measurements included endothelial cell loss (ECL), best-corrected visual acuity (BCVA), central corneal thickness (CCT), and complications.

RESULTS

At 1 month, ECL was 25% (±16%) and 35% (±15%) in DMEK-only and triple-DMEK groups, respectively. At 1 year, ECL was 33% (±13%) and 41% (±16%) in DMEK-only and triple-DMEK groups, respectively. There was statistically significantly less ECL after DMEK-only than after triple-DMEK at both 1 month (95% confidence interval [CI]: 1.67-15.02; P = .016) and 1 year (95% CI: 1.06-14.07; P = .034). CCT was significantly lower after DMEK-only than after triple-DMEK at 1 month but not at 1 year. BCVA was excellent and similar in the 2 groups. There were no cases of graft failure. Graft rejection and rebubbling rates were similar in DMEK-only and triple-DMEK groups: rejection occured in 8.8% and 8.75% of cases respectively (P = .50), and rebubbling in 2.9% and 2.5% respectively (P = .44).

CONCLUSIONS

Both the DMEK-only and the triple-DMEK groups had low rebubbling rates and good visual outcomes, but the combined triple-DMEK procedure resulted in significantly greater loss of endothelial cells than DMEK-only surgery at both 1 month and 1 year.

Long-Term Outcomes of Descemet Membrane Endothelial Keratoplasty in Eyes with Prior Glaucoma Surgery

PURPOSE

The purpose of this study was to evaluate the long-term outcomes of Descemet membrane endothelial keratoplasty (DMEK) in eyes that had previously undergone trabeculectomy and/or drainage device implantation.

DESIGN

Retrospective, noncomparative case series.

METHODS

Medical records of 251 consecutive DMEK procedures performed by 1 surgeon (S.X.D.) from 2013 to 2017 were reviewed. Patients with ≥2 years of follow-up were divided into 3 groups: eyes with prior glaucoma surgery (ST), eyes with medically treated glaucoma (MT), and eyes without glaucoma (NG). Main outcomes measured were visual acuity, endothelial cell count (ECC), rates of secondary graft failure (SGF), and postoperative complications.

RESULTS

Ninety procedures (87 eyes) met inclusion criteria. The mean follow-up period of all eyes was 38.4 ± 11.2 months (range, 24.2-64.4 months). At last follow-up, the proportion of eyes reaching a vision of ≥20/40 was higher than that before the DMEK procedure in each group (all P < .05). The rate of ECC loss was the highest in the ST group compared to that in the MT and NG groups (63.8% vs 47.6% vs 44.0%, respectively; P < .05) as well as the rate of SGF (41.6% vs 0% vs 2.4%, respectively; P < .05). The rate of SGF of repeat DMEK was higher than that of primary DMEK (P < .05). The rates of postoperative complications were similar among all groups (all P > .05).

CONCLUSIONS

In eyes with prior glaucoma surgery, DMEK achieved good long-term visual outcomes but experienced a higher rate of SGF than eyes without such comorbidity.

Descemet Membrane Endothelial Keratoplasty in Children

PURPOSE

To describe the outcomes of Descemet membrane endothelial keratoplasty (DMEK) performed in amblyopic aged (younger than 8 years) children.

METHODS

This is a single-center retrospective study, including 11 eyes (7 congenital hereditary endothelial dystrophy and 4 congenital glaucoma) of 6 children in amblyopic age undergoing DMEK by a single surgeon (N.C.P.) at Sorocaba Eye Hospital from December 2015 to November 2017. Best spectacle-corrected visual acuity, biomicroscopy, pachymetry, endothelial cell density, and complications were evaluated.

RESULTS

No intraoperative complications occurred. Graft detachment occurred in 1 eye (9.1%) and was successfully managed with rebubbling. No primary graft failure or pupillary block was observed. All pachymetric measurements improved, and the corneal edema clinically resolved in all eyes within 2 weeks after the procedure. At the last follow-up (mean 30 months), best spectacle-corrected visual acuity was ≥20/40 in 7 (77.8%) of 9 eyes from patients cooperative enough to assess vision. All children began visual stimulation therapy and amblyopic treatment within 1 month of surgery, and all grafts remained clear until the last follow-up. The mean preoperative donor endothelial cell density was 2588 ± 236 cells/mm, which decreased to 1726 ± 292 cells/mm 2 years after surgery, yielding a 33% reduction (P < 0.001). No immunologic graft reaction, secondary graft failure, or cataracts were observed during the follow-up period.

CONCLUSIONS

In this series, DMEK was performed to successfully treat endothelial dysfunction in children. However, the procedure is more challenging, and more studies with more patients and longer follow-up are needed to confirm the superiority of DMEK in treating endothelial dysfunction in children.

Long-term clinical outcomes after Descemet Membrane Endothelial Keratoplasty (DMEK) in Irido-Corneal Endothelial Syndrome

Purpose

To evaluate the long-term clinical outcomes after Descemet Membrane Endothelial Keratoplasty (DMEK) in Irido-Corneal Endothelial Syndrome (ICE).

Observation

Four eyes of four patients diagnosed with ICE syndrome were treated with DMEK. Postoperatively, best corrected visual acuity (BCVA) and central endothelial cell density (ECD) were documented at 6, 12, 24 and 36 months for all the cases. All procedures were uneventful. Average follow-up time was 36 months. BCVA improved in all eyes. Mean BCVA improved significantly from 1.54 ± 0.71 log MAR preoperatively to 0.11 ± 0.14 logMAR at the final follow-up. Average donor ECD was 2895 ± 357 cells/mm² preoperatively and 1992 ± 321 cells/mm², 1816 ± 395 cells/mm², 1571 ± 299 cells/mm² and 1305 ± 246 cells/mm² at 6, 12, 24 and 36 months after DMEK surgery respectively. This represented an average endothelial cell loss (ECL) of 31.3%, 37.7%, 46.8% and 55.1% at 6, 12, 24 and 36 months respectively. Postoperative intraocular pressure (IOP) rise was seen in 3 eyes at 1 month which normalized under topical antiglaucoma medications.

Conclusion

DMEK is a relatively safe procedure providing favourable clinical outcomes in eyes with ICE syndrome. Since angle closure is progressive in these condition, regular IOP monitoring and glaucoma control is critical for long term survival of the graft.

Importance

Till date management of ICE syndrome has always been a great challenge due to its varied presentation and complex anatomical abnormalities. Replacing the endothelial cells in an irregular anterior chamber poses additional difficulty. Even well-trained DMEK surgeons find it difficult to appose the Descemet's Membrane (DM) in such a scenario and we in this article provide key surgical tips for successful long term management of these cases.

Analyzing pre-symptomatic tissue to gain insights into the molecular and mechanistic origins of late-onset degenerative trinucleotide repeat disease

How genetic defects trigger the molecular changes that cause late-onset disease is important for understanding disease progression and therapeutic development. Fuchs' endothelial corneal dystrophy (FECD) is an RNA-mediated disease caused by a trinucleotide CTG expansion in an intron within the TCF4 gene. The mutant intronic CUG RNA is present at one-two copies per cell, posing a challenge to understand how a rare RNA can cause disease. Late-onset FECD is a uniquely advantageous model for studying how RNA triggers disease because: (i) Affected tissue is routinely removed during surgery; (ii) The expanded CTG mutation is one of the most prevalent disease-causing mutations, making it possible to obtain pre-symptomatic tissue from eye bank donors to probe how gene expression changes precede disease; and (iii) The affected tissue is a homogeneous single cell monolayer, facilitating accurate transcriptome analysis. Here, we use RNA sequencing (RNAseq) to compare tissue from individuals who are pre-symptomatic (Pre_S) to tissue from patients with late stage FECD (FECD_REP). The abundance of mutant repeat intronic RNA in Pre_S and FECD_REP tissue is elevated due to increased half-life in a corneal cells. In Pre_S tissue, changes in splicing and extracellular matrix gene expression foreshadow the changes observed in advanced disease and predict the activation of the fibrosis pathway and immune system seen in late-stage patients. The absolute magnitude of splicing changes is similar in pre-symptomatic and late stage tissue. Our data identify gene candidates for early drivers of disease and biomarkers that may represent diagnostic and therapeutic targets for FECD. We conclude that changes in alternative splicing and gene expression are observable decades prior to the diagnosis of late-onset trinucleotide repeat disease.

Survival of the fittest: phacoemulsification outcomes in four corneal transplants by Dr Ramon Castroviejo

AIM

To evaluate and report the outcomes following phacoemulsification on four eyes, 45 years or more after corneal transplantation.

METHODS

A retrospective case series of four eyes in three patients (P1, P2, P3), undergoing phacoemulsification at least 45 years after corneal transplantation by Dr Ramon Castroviejo. Corneal graft survival outcome measures included central corneal thickness (CCT), best-corrected visual acuity (BCVA), corneal clarity and endothelial cell count (ECC).

RESULTS

Phacoemulsification was successfully completed in all four cases with no instances of graft failure during the postoperative follow-up period, which ranged from 17 months to 76 months. At the conclusion of the follow-up period, all four grafts remained clear, and BCVA remained better than or similar to preoperative values. Long-term follow-up revealed no meaningful changes in CCT after phacoemulsification. All but one case experienced a decrease in ECC, with ECC values in the four cases ranging from 538 cells/mm² to 1436 cells/mm² at the conclusion of postoperative follow-up.

CONCLUSION

Limited data have been published on the long-term survival of corneal grafts after intraocular surgery, especially for extremely 'mature' corneal transplants. This case series demonstrates that with appropriate preoperative, intraoperative and postoperative measures, successful phacoemulsification can be performed in these cases with excellent long-term results.

Ischemic optic neuropathy after Descemet-stripping automated endothelial keratoplasty

An 82-year-old woman presented with a failed Descemet-stripping automated endothelial keratoplasty (DSAEK) in her right eye performed a month earlier. The patient underwent uneventful repeat DSAEK. Six days after the procedure, the patient was found to have an afferent pupillary defect and optic nerve swelling in her right eye on fundoscopy and optical coherence tomography. A comprehensive workup, including bilateral temporal artery biopsies and magnetic resonance imaging, for vasculitic etiologies was negative. A diagnosis of nonarteritic anterior ischemic optic neuropathy (NAION) was made. Although NAION has been reported after various ocular surgeries, to the authors' knowledge, this is the first reported case of NAION after uneventful corneal transplantation. Therefore, NAION should be considered a rare complication of corneal transplantation surgery. Meticulous preoperative and postoperative evaluation, including an attentive pupillary and dilated fundus examination, are essential in assessing a patient's risk factors for this condition and monitoring for its occurrence in the perioperative period.

Corneal Folds After Descemet Membrane Endothelial Keratoplasty in Congenital Hereditary Endotheial Dystrophy

PURPOSE

To report a new clinical sign of corneal folds after Descemet membrane endothelial keratoplasty (DMEK) in the eyes with congenital hereditary endothelial dystrophy (CHED).

METHODS

Retrospective review of cases of CHED who presented with unusual folds in recipient cornea after the DMEK procedure for CHED. Clinical outcomes including visual acuity, pachymetry, specular microscopy, anterior segment optical coherence tomography, and corneal clarity, besides postoperative complications were analyzed.

RESULTS

Fifteen eyes of 11 cases of CHED successfully underwent DMEK. Five eyes of 4 patients, mean age 17.2 ± 5.8 years (range 10-23 years), developed unusual folds in the anterior cornea after resolution of stromal edema. Mean follow-up was 7.8 ± 2.5 months (range 6-12 months). Mean best spectacle-corrected visual acuity improved from 0.8 ± 0.3 LogMAR preoperatively to 0.3 ± 0.2 LogMAR postoperatively. Corneal thickness improved from 991 ± 65 μm (range 924-1088 μm) preoperatively to 595 ± 78 μm postoperatively (range 525-730 μm). Average endothelial cell counts were 1708 ± 271 cell/mm2 at the last follow-up. No intraoperative or postoperative complications were reported. The corneal folds remained unchanged during the follow-up. Comparative analysis with remaining 10 eyes did not show any significant differences.

CONCLUSIONS

Cornea can present with unusual folds in the anterior stroma after successful DMEK in CHED. These folds may possibly be due to difference in collagen structure between anterior and posterior corneal stroma and needs to be studied further.

Quantifying Graft Detachment after Descemet's Membrane Endothelial Keratoplasty with Deep Convolutional Neural Networks

Purpose

We developed a method to automatically locate and quantify graft detachment after Descemet's membrane endothelial keratoplasty (DMEK) in anterior segment optical coherence tomography (AS-OCT) scans.

Methods

A total of 1280 AS-OCT B-scans were annotated by a DMEK expert. Using the annotations, a deep learning pipeline was developed to localize scleral spur, center the AS-OCT B-scans and segment the detached graft sections. Detachment segmentation model performance was evaluated per B-scan by comparing (1) length of detachment and (2) horizontal projection of the detached sections with the expert annotations. Horizontal projections were used to construct graft detachment maps. All final evaluations were done on a test set that was set apart during training of the models. A second DMEK expert annotated the test set to determine interrater performance.

Results

Mean scleral spur localization error was 0.155 mm, whereas the interrater difference was 0.090 mm. The estimated graft detachment lengths were in 69% of the cases within a 10-pixel (∼150 µm) difference from the ground truth (77% for the second DMEK expert). Dice scores for the horizontal projections of all B-scans with detachments were 0.896 and 0.880 for our model and the second DMEK expert, respectively.

Conclusions

Our deep learning model can be used to automatically and instantly localize graft detachment in AS-OCT B-scans. Horizontal detachment projections can be determined with the same accuracy as a human DMEK expert, allowing for the construction of accurate graft detachment maps.

Translational Relevance

Automated localization and quantification of graft detachment can support DMEK research and standardize clinical decision-making.

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.

Corneal graft surgery: A monocentric long-term analysis

PURPOSE

To investigate indications, outcomes and changes in clinical patterns of keratoplasty surgery in a Spanish tertiary eye center.

SETTING

Vissum Instituto Oftalmológico, Alicante, Spain.

METHODS

A retrospective review was performed on clinical records of patients that underwent any kind of corneal transplant from 2001 to 2017 in the study center. Inclusion criteria involved the presence of detailed preoperative examination, surgical report and at least 12 months follow-up after the surgery. A statistical analysis was performed on the indications for keratoplasty, survival rates, type of graft failures, and visual outcomes.

RESULTS

A total of 907 keratoplasties procedures were identified. About 432 penetrating keratoplasty (PK), 148 deep anterior lamellar keratoplasty (DALK), and 134 endothelial keratoplasty (EK) met the inclusion criteria. Cumulative survival rate ranged from 94% to 69% in a 1-year period and from 85% to 45% in a 5-years period according to the different graft types. The main cause for failure was immunological rejection for PK, surface diseases for DALK and primary graft failure for EK. Postoperative visual function improved for all the surgical techniques.

CONCLUSION

Corneal transplant is a challenging surgery still complicated by a relevant risk of failure. Our study offers a useful opinion of the current trends on keratoplasty in our country, where the outcomes of the grafts differ considerably in relation to the indications and the different surgical techniques, with lamellar procedures that showed higher rates of success and better visual outcomes than full-thickness grafts.

One-Year Clinical Outcomes of Preloaded Descemet Membrane Endothelial Keratoplasty Versus Non-Preloaded Descemet Membrane Endothelial Keratoplasty

PURPOSE

To compare the one-year outcomes of preloaded Descemet membrane endothelial keratoplasty (pDMEK) and non-preloaded DMEK (n-pDMEK) in patients with Fuchs endothelial corneal dystrophy (FECD).

METHODS

This retrospective comparative cohort study consecutively included 68 eyes with Fuchs endothelial corneal dystrophy who underwent either pDMEK (n = 38) or n-pDMEK (n = 30) performed by cornea fellows with an experienced surgeon between 2016 and 2018 at the Massachusetts Eye and Ear Infirmary. Exclusion criteria were previous surgery (other than uncomplicated cataract surgery) and any documented evidence of macular or other corneal diseases. Corrected distance visual acuity (CDVA), central corneal thickness, intraocular pressure, patient characteristics, postprocessing endothelial cell count, donor graft data, and complications were compared.

RESULTS

CDVA showed similar results for pDMEK (0.12 ± 0.11 logarithm of the minimal angle of resolution [LogMAR]) and n-pDMEK (0.13 ± 0.13 LogMAR) (P = 0.827). Sixty-six percent of the pDMEK eyes and 57% of the n-pDMEK eyes achieved a VA of ≥0.1 LogMAR, and 95% and 97%, respectively, achieved a CDVA ≥0.3 LogMAR. The preoperative central corneal thickness of pDMEK and n-pDMEK (644 ± 62.2 μm, 660.5 ± 56.2 μm) decreased significantly after surgery (525.1 ± 43.6 μm, 526.5 ± 45.2 μm, P < 0.001), with no difference between groups (P = 0.840). The postprocessing endothelial cell count did not differ between pDMEK (2959.2 ± 182.9 cells/mm2) and n-pDMEK (2939.3 ± 278.7 cells/mm2) (P = 0.484). Complication rates were comparable with just the rebubbling performed in a minor procedure room showing a lower rate for pDMEK (13.16%) compared with n-pDMEK (33.33%) (P < 0.045).

CONCLUSIONS

One-year clinical outcomes were similar between pDMEK and n-pDMEK procedures, rendering eye bank-prepared pDMEK tissues a useful tool in the treatment of endothelial dysfunction.

Role of Anterior Segment OCT for Descemet Membrane Stripping During Descemet Membrane Endothelial Keratoplasty in Eyes With Congenital Hereditary Endothelial Dystrophy

PURPOSE

To report the utility of preoperative anterior segment optical coherence tomography (ASOCT) in decision-making for stripping of the Descemet membrane (DM) during Descemet membrane endothelial keratoplasty (DMEK) in eyes with congenital hereditary endothelial dystrophy (CHED).

METHODS

ASOCT was performed in eyes with CHED undergoing DMEK. Host DM was retained if the DM appearance was normal on ASOCT. Outcomes of DMEK with or without DM stripping (non DM stripping [DMEK]) were analyzed and compared regarding graft adhesion, graft clarity, visual acuity, and complications.

RESULTS

Twelve eyes of 8 patients were included in the series. Of these, 6 eyes (mean age, 6 ± 2.6 years, range 3-8 years) underwent nDMEK and 6 eyes (mean age, 23.6 ± 10.2 years, range 13-39 years) underwent standard DMEK. There were no intraoperative complications in either group. During the early postoperative period, one eye in the nDMEK group had donor detachment that was successfully managed by repeat air injection. The mean preoperative and postoperative corrected visual acuities were 1.15 and 0.37 logarithm of the minimum angle of resolution (LogMAR) in the nDMEK group, and 0.95 and 0.25 LogMAR in the DMEK group (P 0.39 and 0.06). Average endothelial cell counts were 1826 ± 318 cell/mm in the nDMEK group (32.3% loss), and 1708 ± 271 cells/mm in the DMEK group (33.6% loss) at the last follow-up.

CONCLUSIONS

Preoperative anterior segment OCT is useful in decision-making regarding stripping of host DM during DMEK in eyes with CHED. The outcomes of nDMEK were similar to DMEK in this small series.

New Technologies in Clinical Trials in Corneal Diseases and Limbal Stem Cell Deficiency: Review from the European Vision Institute Special Interest Focus Group Meeting

To discuss and evaluate new technologies for a better diagnosis of corneal diseases and limbal stem cell deficiency, the outcomes of a consensus process within the European Vision Institute (and of a workshop at the University of Cologne) are outlined. Various technologies are presented and analyzed for their potential clinical use also in defining new end points in clinical trials. The disease areas which are discussed comprise dry eye and ocular surface inflammation, imaging, and corneal neovascularization and corneal grafting/stem cell and cell transplantation. The unmet needs in the abovementioned disease areas are discussed, and realistically achievable new technologies for better diagnosis and use in clinical trials are outlined. To sum up, it can be said that there are several new technologies that can improve current diagnostics in the field of ophthalmology in the near future and will have impact on clinical trial end point design.

Comparison of the Success Rate of Two Different Marking Techniques (F-Mark and Asymmetric Triangular Mark) to Orient the Donor Graft During Descemet Membrane Endothelial Keratoplasty

OBJECTIVES

We evaluated the effects of various graft-marking techniques on surgical results in patients undergoing Descemet membrane endothelial keratoplasty.

MATERIALS AND METHODS

In this single-center retrospective study, 65 eyes from 55 patients that had received various types of marking or no marking and that had been used for Descemet membrane endothelial keratoplasty endothelial graft preparation were included. Patients were divided into 3 groups according to the marking technique used: group I (F-marked graft; 17 eyes), group II (asymmetric triangle-marked graft; 12 eyes), and group III (unmarked graft; 36 eyes). The main outcome measurements were best-corrected visual acuity, endothelial cell density, central corneal thickness, postoperative complications, rebubbling, and secondary keratoplasty rates.

RESULTS

In groups I, II, and III, rates of patients with 6-month best-corrected visual acuity ≥ 20/32 were 35.7%, 77.8%, and 71.9%, respectively (P = .04). The mean 6-month endothelial cell density decrease for each group was 43.3%, 48.8%, and 46.4%, respectively (P = .589), whereas the mean 6-month central corneal thickness decrease for each group was 7.7%, 15.8%, and 34.0%, respectively (P = .001). Rates of primary graft failure for groups I, II, and III were 35.3%, 8.3%, and 13.9%, respectively. Rebubbling was performed in 21.5% of eyes, and secondary keratoplasty was required in 29.2% of eyes.

CONCLUSIONS

Although graft-marking techniques for Descemet membrane endothelial keratoplasty greatly facilitate graft positioning during surgery, both the potential toxic effects of alcohol on the endothelium when marking with gentian violet dye and the risk of graft detachment with asymmetric marking must be considered.