How Would Nature See Our Corneal Triumphs? The LXXIX Edward Jackson Lecture.

PURPOSE: To describe discrepancies between clinical observation and current teachings in corneal endothelial disease, particularly in Fuchs endothelial dystrophy and its potential association with primary open angle glaucoma. DESIGN: Perspective. METHODS: A perspective is presented on Fuchs dystrophy, a disorder that commonly presents with a compromised endothelium but minimal stromal edema, indicating that the corneal imbibition pressure is relatively "too high." RESULTS: The discrepancy between the relative lack of stromal edema in the absence of an endothelial cell layer cannot be explained by the current theories involving a circulatory pumping mechanism over the endothelial cell layer, but may point to the following: (1) secondary involvement of the corneal endothelium in Fuchs dystrophy; (2) separate hydration systems for maintaining the imbibition pressure (vertical static hydration) and corneal nutrition (horizontal dynamic hydration); (3) the cornea as net contributor of aqueous humor; (4) a close relationship between the corneal imbibition and intraocular pressure, with potentially a shared regulatory system; and (5) a potential steroid-type hormone dependency of this regulatory system. CONCLUSIONS: Clinical observation shows that the stromal imbibition pressure is "too high" in Fuchs endothelial dystrophy, indicating that it may not primarily be an endothelial disease, but a type of "corneal glaucoma."

Corneal Guttae After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: The aim of this study was to report on the occurrence of corneal guttae after Descemet membrane endothelial keratoplasty (DMEK). METHODS: In this retrospective case series, 13 eyes of 13 patients who underwent DMEK at 2 tertiary referral centers between 2007 and 2021 (average available follow-up 73 ± 52 months, range 18-174 months) and showed corneal guttae during postoperative examinations were included. Eye bank images were retrospectively reviewed. RESULTS: Occurrence of guttae was observed by specular microscopy in 13 eyes. In 11 cases, presence of guttae was confirmed by confocal microscopy and in 1 case by histology. Five eyes showed an increase in guttae density during the postoperative course. Surgery indications were Fuchs endothelial corneal dystrophy (n = 11), pseudophakic bullous keratopathy (n = 1), and DMEK graft failure after allograft rejection (n = 1); the latter eye had shown no signs of guttae after primary DMEK. Two eyes with guttae required a repeat DMEK due to graft failure. At the last available follow-up, all 11 remaining eyes had clear corneas and 10 eyes had a best-corrected visual acuity of ≥0.9 (decimal). During donor cornea processing in the eye bank, no guttae were observed on the donor tissue. CONCLUSIONS: Corneal guttae can occur after DMEK including in eyes operated for indications other than Fuchs endothelial corneal dystrophy and most likely guttae were present on the donor graft but were not detectable by routine slit-lamp and light microscopy evaluation in the eye bank. Postoperative guttae density varies among patients and especially small isolated guttae do not seem to affect clinical outcomes.

Corneal endothelial wound healing: understanding the regenerative capacity of the innermost layer of the cornea.

Currently, there are very few well-established treatments to stimulate corneal endothelial cell regeneration in vivo as a cure for corneal endothelial dysfunctions. The most frequently performed intervention for a damaged or dysfunctional corneal endothelium nowadays is corneal endothelial keratoplasty, also known as lamellar corneal transplantation surgery. Newer medical therapies are emerging and are targeting the regeneration of the corneal endothelium, helping the patients regain their vision without the need for donor tissue. Alternatives to donor tissues are needed as the aging population requiring transplants, has further exacerbated the pressure on the corneal eye banking system. Significant ongoing research efforts in the field of corneal regenerative medicine have been made to elucidate the underlying pathways and effector proteins involved in corneal endothelial regeneration. However, the literature offers little guidance and selective attention to the question of how to fully exploit these pathways. The purpose of this paper is to provide an overview of wound healing characteristics from a biochemical level in the lab to the regenerative features seen in the clinic. Studying the pathways involved in corneal wound healing together with their key effector proteins, can help explain the effect on the proliferation and migration capacity of the corneal endothelial cells.

Long-Term Outcomes of Bowman Layer Inlay Transplantation for the Treatment of Progressive Keratoconus.

PURPOSE: To report long-term clinical outcomes and estimated success rates after Bowman layer (BL) inlay transplantation in eyes treated for progressive keratoconus (KC). METHODS: Thirty-five eyes (29 patients) with progressive KC underwent BL inlay transplantation. Best-corrected spectacle and contact lens visual acuity, Scheimpflug-based corneal tomography [simulated and maximum keratometry (Kmax)], central corneal thickness, thinnest point thickness, complications, and success rate were evaluated up to 8 years postoperatively for the total group and 2 subgroups [group 1: preoperative Kmax > 69 diopter (D) (n = 26); group 2: preoperative Kmax < 69D (n = 9)]. RESULTS: Mean logarithm of the minimum angle of resolution best contact lens-corrected visual acuity for the total group and the 2 subgroups did not change from preoperative up to the last available follow-up (all P > 0.05), whereas best spectacle-corrected visual acuity improved for group 1 ( P = 0.03). Group 1 showed an average Kmax reduction of 7D in the first month ( P < 0.001) with no further changes up to 8 years postoperatively ( P > 0.05), whereas no significant changes were observed in group 2 (all P > 0.05). Postoperative KC progression occurred in 4 eyes (n = 3 group 1, n = 1 group 2) and 1 eye (group 2) underwent retransplantation for unsatisfactory visual performance. Kaplan-Meier analysis showed an estimated success rate of 85% at the 5 to 8 years follow-up in group 1 and of 75% at the 5 to 7 years follow-up for group 2. CONCLUSIONS: BL inlay transplantation stabilized KC in most eyes along with preservation of contact lens tolerance up to 8 years postoperatively and may be a successful treatment option, in particular for eyes with progressive advanced KC (Kmax > 69D).

Endothelial Cell Viability after DMEK Graft Preparation.

Aim: To evaluate the effect of graft preparation and organ-culture storage on endothelial cell density (ECD) and viability of Descemet membrane endothelial keratoplasty (DMEK) grafts.Materials and methods: DMEK grafts (n = 27) were prepared at Amnitrans EyeBank Rotterdam from 27 corneas (15 donors) that were eligible for transplantation but could not be allocated due to the Covid-19-related cancellation of elective surgeries. Cell viability (by Calcein-AM staining) and ECD of five grafts originally scheduled for transplantation were evaluated on the originally planned surgery day, whereas 22 grafts from paired donor corneas were evaluated either directly post-preparation or after 3-7 days of storage. ECD was analyzed by light microscopy (LM ECD) and Calcein-AM staining (Calcein-ECD).Results: Light microscopy (LM) evaluation of all grafts showed an unremarkable endothelial cell monolayer directly after preparation. However, median Calcein-ECD for the five grafts initially allocated for transplantation was 18% (range 92-73%) lower than median LM ECD. For the paired DMEK grafts, Calcein-ECD determined by Calcein-AM staining on the day of graft preparation and after 3-7 days of graft storage showed a median decrease of 1% and 2%, respectively. Median percentage of central graft area populated by viable cells after preparation and after 3-7 days of graft storage was 88% and 92%, respectively.Conclusion: Cell viability of most of the grafts will not be affected by preparation and storage. Endothelial cell damage may be observed for some grafts within hours after preparation, with insignificant additional ECD changes during 3-7 days of graft storage. Implementing an additional post-preparation step in the eye bank to evaluate cell density before graft release for transplantation may help to reduce postoperative DMEK complications.

Preclinical testing of small diameter Descemet membrane endothelial keratoplasty grafts to increase tissue availability.

In this study, we describe a process of preparing, surgically manipulating, and validating a novel "small diameter" 4mm circular Descemet membrane endothelial keratoplasty (DMEK) graft in vitro. Three small diameter DMEK grafts can be prepared from a single donor endothelium and could, therefore, potentially expand the donor pool. Prior to clinical use, however, we aimed to examine each step of the process to determine the effect on the endothelial cell loss and whether or not cells retained their capacity to migrate uniformly. For this study, circular small diameter grafts, obtained from twelve corneas of ten donors deemed ineligible for transplantation, were included. Small diameter DMEK graft preparation was successful in all cases (n = 36). Endothelial cell density (ECD), determined in the eye bank on seventeen grafts, showed an average decrease from 2413 (±189) cells/mm2 before to 2240 (±413) cells/mm2 after preparation. Twenty-four grafts were used to simulate DMEK-surgery in vitro and were successfully stained with 0.06% trypan blue, loaded into a straight DMEK-injector, unfolded, positioned, and centered within the circular ~ 4mm descemetorhexis. The estimated % area populated by viable cells on the grafts decreased from on average 92 (±3) % before to 78 (±10) % (n = 4) after in vitro surgery. Cells displayed a capacity for uniform cell migration from all edges of the graft (n = 4) when embedded in the 3D hydrogel system. Our data show, that by using an in vitro model of DMEK-surgery it was possible to test the 4mm circular DMEK grafts from eye bank preparation to surgical implantation. The cell loss after in vitro surgery was comparable with the in vivo ECD decline early after DMEK and the capacity of the cells to migrate to potentially cover bare stroma indicates that these small diameter grafts may be a viable clinical option to treat central endothelial disease.

Phacoemulsification After Descemet Membrane Endothelial Keratoplasty: Incidence and Influence on Endothelial Cell Density.

PURPOSE: To analyze the incidence of cataract extraction after Descemet membrane endothelial keratoplasty (DMEK) in phakic eyes and to evaluate the effect of phacoemulsification after DMEK on the donor endothelial cell density (ECD). METHODS: The clinical data of phakic patients with DMEK were examined. From this cohort, all patients who subsequently underwent phacoemulsification after DMEK were reviewed. Data from a prospectively collected dataset were analyzed, including demographic profile, ECD, corrected distance visual acuity (CDVA), central corneal thickness (CCT), and complications. RESULTS: From a series of 261 phakic patients with DMEK, 35 eyes (13.4%) required cataract surgery within the mean follow-up period of 54.2 ± 28 months. The mean time from DMEK to phacoemulsification was 18 ± 13 months (range: 3 to 69 months). The probability of cataract extraction after DMEK was 0.06 (95% CI: 0.03 to 0.09) at 1 year and 0.17 (95% CI: 0.12 to 0.22) at 10 years, respectively. ECD decreased from 1,314 ± 524 cells/mm2 before phacoemulsification to 1,167 ± 443 cells/mm2 (-11%) at 1 to 6 months postoperatively (P = .333). CDVA improved from 0.27 ± 0.13 logMAR preoperatively to 0.07 ± 0.12 logMAR at 1 to 6 months postoperatively. CCT before phacoemulsification was 532 ± 46 µm and remained stable at 539 ± 56 µm at 1 to 6 months after phacoemulsification. Phacoemulsification did not elicit DMEK graft detachment in any of the eyes studied. CONCLUSIONS: The incidence and 10-year projection of cataract extraction in phakic eyes with DMEK was relatively low. Phacoemulsification after DMEK provided excellent CDVA outcomes, did not induce graft detachment, and was associated with an acceptable decrease in ECD. [J Refract Surg. 2021;37(2):119-125.].

New developments in corneal endothelial cell replacement.

Corneal transplantation is currently the most effective treatment to restore corneal clarity in patients with endothelial disorders. Endothelial transplantation, either by Descemet membrane endothelial keratoplasty (DMEK) or by Descemet stripping (automated) endothelial keratoplasty (DS(A)EK), is a surgical approach that replaces diseased Descemet membrane and endothelium with tissue from a healthy donor eye. Its application, however, is limited by the availability of healthy donor tissue. To increase the pool of endothelial grafts, research has focused on developing new treatment options as alternatives to conventional corneal transplantation. These treatment options can be considered as either 'surgery-based', that is tissue-efficient modifications of the current techniques (e.g. Descemet stripping only (DSO)/Descemetorhexis without endothelial keratoplasty (DWEK) and Quarter-DMEK), or 'cell-based' approaches, which rely on in vitro expansion of human corneal endothelial cells (hCEC) (i.e. cultured corneal endothelial cell sheet transplantation and cell injection). In this review, we will focus on the most recent developments in the field of the 'cell-based' approaches. Starting with the description of aspects involved in the isolation of hCEC from donor tissue, we then describe the different natural and bioengineered carriers currently used in endothelial cell sheet transplantation, and finally, we discuss the current 'state of the art' in novel therapeutic approaches such as endothelial cell injection.

Three-quarter DMEK in eyes with glaucoma draining devices to avoid secondary graft failure.

PURPOSE: To present a case series of a modified three-quarter Descemet's membrane endothelial keratoplasty (3/4-DMEK) technique to treat pseudophakic bullous keratopathy in the presence of a glaucoma drainage device (GDD) tube in the anterior chamber by reducing the risk of donor endothelial damage due to absence of donor endothelial cells overlying the GGD tube area. METHODS: In this prospective case series, four eyes of three patients with stable glaucoma underwent 3/4-DMEK surgery for pseudophakic bullous keratopathy after GDD insertion. The patients were followed up to 24 ± 2.5 months postoperatively. RESULTS: No intraoperative or postoperative complications were noted. The average central endothelial cell density (ECD) was 1093 ± 74 cells/mm2 at 12 months postoperatively, corresponding to an ECD decrease of 58 (±6)% as compared to preoperative values. Average best-corrected visual acuity increased from finger counting before surgery to 20/60 (logMar 0.5) at 12 months after 3/4-DMEK and remained stable up to 24 months postoperatively. All corneas remained clear at the last available follow-up. CONCLUSION: This case series demonstrates the technical feasibility of 3/4-DMEK in eyes with pseudophakic bullous keratopathy in the presence of a GDD tube. The absence of a donor DM and donor cells above the silicone tube excludes direct tube contact with the graft. Longer term studies are needed to show the effect of this modified graft pattern and dimensions on transplant survival.

In Vitro Evaluation and Transplantation of Human Corneal Endothelial Cells Cultured on Biocompatible Carriers.

Corneal transplantation is currently the only effective treatment option for dysfunctional corneal endothelial cells (CEC). In this study, we test in vitro the surgical potential of cultivated human corneal endothelial cells (hCEC) on human anterior lens capsule (HALC), LinkCell™ bioengineered collagen sheets of 20-µm thickness (LK20), and denuded Descemet membrane (dDM) as tissue-engineered grafts for Descemet membrane (DM) endothelial keratoplasty (DMEK) to bypass the problem of donor tissue availability. Primary hCEC cultured on all carriers formed a monolayer of tightly packed cells with a high cell viability rate (96% ± 4%). hCEC on HALC and LK20 showed unremarkable expression of zonula occludens-1 (ZO-1) and Na+/K+-adenosine triphosphatase (ATPase), while Na+/K+-ATPase expression of cells seeded on dDM was mainly cytoplasmic. All hCEC-carrier constructs were evaluated by simulating DMEK surgery in vitro using a human donor cornea without DM mounted on an artificial anterior chamber (AC) and a regular DMEK-graft used as a surgical reference model. During in vitro surgery, hCEC-HALC constructs behaved most similarly to a DMEK-graft during implantation and unfolding, showing good adhesion to the bare stroma. On the other hand, hCEC-LK20 and hCEC-dDM constructs required some additional handling because of challenges related to the surgical procedure, although they were both successfully unfolded and implanted in the artificial AC. The hCEC-dDM constructs showed similar graft adherence as hCEC-HALC constructs, while adherence of hCEC-LK20 constructs was less effective. After the in vitro surgery, the estimated area populated by viable cells on the hCEC-HALC and hCEC-LK20 constructs was ∼83% and ∼67%, respectively. Overall, hCEC-HALC constructs behaved most similarly to a DMEK-graft during in vitro DMEK surgery, while graft adhesion and surgical handling, respectively, are parameters still requiring optimization for hCEC-LK20 and hCEC-dDM constructs.

Bowman Layer Onlay Graft for Reducing Fluctuation in Visual Acuity After Previous Radial Keratotomy.

PURPOSE: To describe the clinical outcome of a first patient undergoing Bowman layer (BL) transplantation with an onlay graft to reduce fluctuation in visual acuity and refractive error after previous radial keratotomy (RK) surgery. METHODS: In 2018, a 66-year-old woman presented with complaints of long-standing diurnal fluctuation in best-spectacle corrected visual acuity (BSCVA) after RK in 1983. After the removal of host epithelium, a BL graft was positioned onto the host cornea. BSCVA, Scheimpflug-based corneal tomography, and anterior segment optical coherence tomography were evaluated up to 12 months postoperatively. RESULTS: The surgery and postoperative course were uneventful. After surgery, the subjective complaints of visual fluctuation were reduced from 10 to 3 on a scale from 1 to 10. BSCVA (20/40; 0.5) did not change from preoperative to postoperative. Corneal tomography showed an overall central corneal steepening of 5.9 diopters. Biomicroscopy, Scheimpflug imaging, and anterior segment optical coherence tomography showed a completely epithelialized and well-integrated graft, with some minor epithelial remnants located in the preexisting keratotomy incisions. CONCLUSIONS: BL onlay grafting may have the potential to manage patients with subjective complaints of diurnal fluctuation in visual acuity after previous RK.

Spontaneous Descemet Membrane Detachment After Penetrating Keratoplasty-Clinical Presentation and Outcome of Air/Gas Descemetopexy.

PURPOSE: To describe the clinical characteristics and treatment of spontaneous Descemet membrane (DM) detachment occurring decades after penetrating keratoplasty (PK). METHODS: A multicenter interventional case series design was used. We reviewed the medical records of 4 patients with a history of PK presenting with spontaneous DM detachment at 3 university hospitals in Israel and an ocular surgery institute in The Netherlands in 2016 to 2019. Patient demographic and clinical data, postoperative best corrected visual acuity, findings on preoperative and postoperative anterior segment optical coherence tomography (AS-OCT), and graft survival were recorded. RESULTS: Patients were aged 46 to 50 years. All had undergone PK for keratoconus 20 to 26 years previously. Patients presented within 18 to 180 days of onset of visual disturbance. Symptoms included sudden painless visual loss (2 patients), gradual visual loss and foreign body sensation (1 patients), and visual loss not otherwise specified (1 patient). Slit-lamp examination showed corneal edema, and AS-OCT showed DM detachment of variable extent. In 2 patients, the initial diagnosis was graft rejection and failure. Treatment consisted of anterior chamber injection of air (n = 3) or 20% SF6 (n = 1). In 3 patients, the DM reattached and the cornea regained its clarity. The fourth patient had persistent DM detachment that required repeated PK. CONCLUSIONS: Spontaneous DM detachment can mimic late graft failure in patients after PK. If diagnosed early, DM reattachment may be performed by air/gas injection, avoiding repeated keratoplasty. Eyes with presumed late penetrating graft rejection or failure should be examined by AS-OCT to exclude DM detachment.

Descemet Membrane Endothelial Keratoplasty: Ten-Year Graft Survival and Clinical Outcomes.

PURPOSE: To evaluate the 10-year graft survival and clinical outcomes of the first case series after Descemet membrane endothelial keratoplasty (DMEK). DESIGN: Retrospective, interventional case series. METHODS: After excluding the very first 25 DMEK eyes that constitute the technique learning curve, the following 100 consecutive primary DMEK eyes (88 patients) were included. Main outcome parameters (survival, best-corrected visual acuity [BCVA], central endothelial cell density [ECD], and central corneal thickness [CCT]) were evaluated up to 10 years postoperatively, and postoperative complications were documented. RESULTS: At 5 and 10 years after DMEK, 68 and 57 of 100 eyes, respectively, were still available for analysis. Of those eyes, 82% and 89% reached a BCVA of ≥20/25 (decimal VA ≥0.8) at 5- and 10 years postoperatively, respectively. Preoperative donor ECD decreased by 59% at 5 years and 68% at 10 years postoperatively. CCT averaged 668 ±74 µm preoperatively and 540 ± 33 µm and 553 ± 43 µm at 5 and 10 years, respectively, after surgery. Within 10 years, 4% of eyes developed allograft rejection, no primary graft failures occurred, and 6% of the eyes developed secondary graft failure. Graft survival probability was 0.83 (95% confidence interval [CI], 0.75-0.92) and 0.79 (95% CI, 0.70-0.88) at 5 and 10 years postoperatively, respectively. CONCLUSIONS: Most eyes that underwent surgery in the pioneering phase of DMEK showed excellent and stable clinical outcomes with low postoperative complication rates and promising graft longevity over the first decade after surgery. This suggests that DMEK may be a safe long-term treatment option for corneal endothelial diseases.

DMEK in Super-Seniors: Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty Performed in Patients ≥ 90 Years Old.

PURPOSE/AIMS OF THE STUDY: To evaluate the clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) performed in the "oldest old" patients, i.e. ≥ 90 years. MATERIALS AND METHODS: Between the years of 2009 and 2019, 20 consecutive eyes of 17 patients aged ≥ 90 underwent DMEK for endothelial dysfunction. Best corrected visual acuity (BCVA), central corneal thickness (CCT), endothelial cell density (ECD), graft survival, and intra- and postoperative complications were assessed. RESULTS: Except in one case in which the DMEK surgery could not be completed, all operated eyes experienced an improvement in BCVA, although only 50% achieved ≥ 20/40 (0.5) by 1 year postoperatively. One year after surgery, median CCT had declined from 641(±161) µm to 480 (±34) µm, and median endothelial cell density was reduced by 53%, from 2574 (±286) to 1226 (±404) cells/mm2. Six of 19 eyes receiving DMEK grafts (32%) developed partial graft detachments requiring re-bubbling. One eye experienced a secondary graft failure at 6 months and underwent repeat endothelial keratoplasty. CONCLUSION: DMEK is technically feasible in the oldest old patients and may yield significant visual improvements, although an elevated risk of some postoperative complications including graft detachment with corresponding need for re-bubbling may be anticipated.

In Vitro Evaluation of the Feasibility of Slit-Lamp Nd: YAG Laser Descemetorhexis.

PURPOSE: To evaluate in vitro the feasibility and tissue effects of using a slit-lamp neodymium-doped yttrium aluminum garnet (Nd:YAG) laser to create a central descemetorhexis in human donor corneas. METHODS: Twelve human donor corneas ineligible for transplantation were divided into 2 groups, A and B. Group A: 2 "healthy" corneas, which were used to validate the laser parameters; group B: 10 corneas with endothelial guttae, which were used to perform a 4-mm descemetorhexis. Slit-lamp photography, light microscopy, corneal endothelial microscopy, Scheimpflug imaging, optical coherence tomography (OCT) imaging, and histological staining were performed to visualize the efficacy of slit-lamp Nd:YAG laser removal of Descemet membrane and to assess potential tissue damage to the overlying stroma and peripheral endothelium. RESULTS: In all corneas, an Nd:YAG laser 4-mm central descemetorhexis could be consistently performed. The total energy required ranged from 1143 to 2784 mJ. Side effects such as stromal pitting and corneal swelling were observed. CONCLUSIONS: Creating a central descemetorhexis with a slit-lamp Nd:YAG laser proved feasible in vitro. This new technical approach might open the door to a customized in vivo "descemetorhexis-only" treatment for Fuchs endothelial corneal dystrophy eyes, while avoiding the risks associated with intraocular surgery.

Parameters Associated With Endothelial Cell Density Variability After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To evaluate which parameters may affect endothelial cell loss after Descemet membrane endothelial keratoplasty (DMEK) by comparing eyes in the low vs high quartile of endothelial cell loss over a follow-up period of 4 years. DESIGN: Retrospective cohort study. METHODS: Donor endothelial cell density (ECD) decline was evaluated for 351 eyes of 275 patients up to 4 years after DMEK for Fuchs endothelial corneal dystrophy (FECD). Eyes with a postoperative endothelial cell loss in the lower quartile at all available follow-up moments were assigned to Group 1 (n = 51) and those in the upper quartile to Group 2 (n = 42). Multinomial regression was used to assess which covariates were related to greater ECD decline. RESULTS: Mean endothelial cell loss as compared to preoperative donor ECD for the entire study group was 33 (±16)%, 36 (±17)%, and 52 (±18)% at 1, 6, and 48 months postoperatively. Endothelial cell loss of Group 1 was 12 (±7)%, 13 (±6)%, and 26 (±8)% at, respectively, 1, 6, and 48 months postoperatively, and 59 (±10)%, 64 (±9)%, and 75 (±5)% in Group 2. Partial graft detachment, donor death cause cardiovascular/stroke (vs cancer), postoperative complications other than graft detachment, and severity of preoperative FECD (all P < .01) showed the strongest relation with greater ECD decline. CONCLUSIONS: DMEK eyes with a completely attached graft and operated in an early stage of FECD may show the lowest endothelial cell loss postoperatively.

Five-Year Graft Survival and Clinical Outcomes of 500 Consecutive Cases After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To report the 5-year graft survival and clinical outcomes after Descemet membrane endothelial keratoplasty (DMEK). METHODS: A retrospective, interventional case series was performed at a tertiary referral center. Five hundred eyes of 393 patients that underwent DMEK for Fuchs endothelial corneal dystrophy, bullous keratopathy, failed previous corneal transplants other than DMEK, or other indications were evaluated for graft survival, best-corrected visual acuity (BCVA), endothelial cell density, postoperative complications, and retransplantation rate. RESULTS: Kaplan-Meier analysis demonstrated an estimated survival probability of 0.90 [95% confidence interval, 0.87-0.94] for the entire cohort at 5 years after DMEK. At this time point, 82% of the eyes achieved a BCVA of ≥20/25 (0.8), 54% achieved ≥20/20 (1.0), and 16% achieved ≥20/17 (1.2). BCVA continued to improve from 6 to 36 months after DMEK surgery (P ≤ 0.005) and then remained stable up to 60 months postoperatively (P > 0.08). Preoperative donor endothelial cell density averaged 2530 (±210) cells/mm and decreased by 37% at 6 months, 40% at 1 year, and 55% at 5 years after DMEK surgery (P < 0.001 between all follow-up time points). During the study period, allograft rejection episodes developed in 2.8% of the eyes, primary graft failure occurred in 0.2%, and secondary graft failure in 2.8% of the eyes. Re-keratoplasty was required in 8.8% of the eyes. CONCLUSIONS: Five-year graft survival after DMEK is high, and visual acuity outcomes remain excellent and are accompanied by a low longer-term complication rate.

Effect of Surgical Indication and Preoperative Lens Status on Descemet Membrane Endothelial Keratoplasty Outcomes.

PURPOSE: To analyze 6-month results of 1000 consecutive Descemet membrane endothelial keratoplasty (DMEK) cases, and to evaluate if outcomes are influenced by surgical indication and preoperative lens status. DESIGN: Retrospective, interventional case series. METHODS: A series of 1000 eyes (738 patients) underwent DMEK mainly for Fuchs endothelial corneal dystrophy (FECD; 85.3%) or bullous keratopathy (BK; 10.5%). Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density, postoperative complications, and retransplantations. RESULTS: At 6 months after DMEK, there was no difference in BCVA outcome between FECD and BK eyes (P = .170), or between phakic and pseudophakic FECD eyes (P = .066) after correcting for patient age and preoperative BCVA. Endothelial cell loss at 6 months postoperatively was similar for phakic and pseudophakic FECD eyes (39%; P = .852), but higher for BK eyes than for FECD eyes (46% vs 39%, P = .001). Primary and secondary graft failure occurred in 3 (0.3%) and 2 eyes (0.2%), respectively, and 7 eyes developed allograft rejection (0.7%). Eighty-two eyes (8.2%) received rebubbling for graft detachment and retransplantation was performed in 20 eyes (2.0%). Rebubbling was more often required in eyes treated for BK vs FECD eyes (12.4% vs 7.4%, P = .022). CONCLUSION: DMEK consistently provides excellent short-term results, with similar high visual acuity levels for both FECD and BK eyes. As preoperative lens status did not influence DMEK outcomes, for phakic FECD eyes with a still relatively clear crystalline lens, lens preservation may be preferable in a selected group of younger patients, who may still benefit from their residual accommodative capacity.