6-month Endothelial Cell Loss Research Articles

Rate of Endothelial Cell Loss and Graft Survival in Descemet Membrane Endothelial Keratoplasty in Eyes Requiring a Rebubble.

We aimed to compare the rate of 6-month endothelial cell loss (ECL) and 6-month graft survival in eyes that did not require a postoperative rebubble with eyes that did require a postoperative rebubble after Descemet membrane endothelial keratoplasty (DMEK) surgery. A consecutive series of DMEK surgeries performed from September 2013 to March 2020 was retrospectively analyzed. Eyes that did not require a rebubble for graft detachment were compared with eyes with 1 rebubble and eyes with 2 or more rebubbles for 6-month ECL and graft survival. A subanalysis of the rebubble rate for different indications for transplantation was also performed. One thousand two hundred ninety-eight eyes were included in this study. The 6-month ECL for eyes with no rebubbles, 1 rebubble, and ≥2 rebubbles was 29.3% ± 16.2% (n = 793), 36.4% ± 18.6% (n = 97, P = 0.001), and 50.1% ± 19.6% (n = 28, P < 0.001), respectively. The 6-month graft survival rate for eyes with no rebubbles, 1 rebubble, and ≥2 rebubbles was 99.5%, 97.8% ( P = 0.035), and 81.8% ( P < 0.001), respectively. When compared to the rebubble rate for DMEK for Fuchs dystrophy (156/1165 eyes = 13.4%), the rebubble rates were statistically higher for DMEK for failed penetrating keratoplasty (28.5%, P = 0.021) and pseudophakic bullous keratopathy (28.0%, P = 0.036). Eyes undergoing any rebubble procedure in the postoperative period after DMEK have an increased risk of endothelial cell loss and graft failure at 6 months postoperative. DMEK in eyes for failed penetrating keratoplasty and failed DMEK had the highest rebubble rate, with the former reaching statistical significance.

Descemet Membrane Endothelial Keratoplasty in Eyes With Chronic Ocular Hypotony Following Glaucoma Surgery

To assess the outcomes of Descemet membrane endothelial keratoplasty (DMEK) in patients with ocular hypotony after glaucoma surgery. retrospective case series. Setting: Multicenter retrospective case series. Hypotonic eyes with prior glaucoma surgery that underwent DMEK between January 2013 and July 2019 in Israel (2 centers) and Canada (1 center). Pre/postoperative corrected distance visual acuity, complications, 3- to 6-month endothelial cell loss, and intraocular pressure (IOP). The study included 11 DMEK procedures performed in 10 eyes of 4 males and 6 females aged 65-84 years. Indications for DMEK included 7 cases of pseudophakic bullous keratopathy, 2 cases of failed DMEK, and 1 case of failed Descemet stripping automated endothelial keratoplasty. All patients had at least 1 previous trabeculectomy operation. One patient had 2 trabeculectomy procedures and 1 tube placement procedure. Two patients had 1 previous trabeculectomy and 1 tube placement procedure. The corrected distance visual acuity improved significantly from 1.52 ± 0.68 logarithm of minimal angle of resolution preoperatively to 0.49 ± 0.32 logarithm of minimal angle of resolution 3 months postoperatively (P < .001). Rebubbling occurred in 3 of 11 procedures (27%). Endothelial cell loss 6-12 months postoperatively was 60% ± 16% (range, 41%-89%). At the last follow-up visit, 6 of 11 (54%) of the grafts were clear. The remaining 5 grafts failed at 1-4 years postoperatively. The preoperative IOP was 5.1 ± 1.6 mm Hg (range, 1-7 mm Hg). In all but one patient, the postoperative IOP did not increase to more than 13 mm Hg. In 2 cases, the IOP decreased from 5 and 7 mm Hg preoperatively to 1 mm Hg 1 year postoperatively. DMEK is a valid procedure for the treatment of corneal edema in hypotonic eyes after glaucoma procedures. These eyes benefit from improvement in vision after DMEK.

Donor DMEK Tissue Characteristics: Association With Rebubble Rate and 6-Month Endothelial Cell Loss.

To determine whether specific donor characteristics influence postoperative rebubble rate and 6-month endothelial cell loss (ECL) in Descemet membrane endothelial keratoplasty (DMEK). A retrospective analysis of a consecutive series of 857 DMEK surgeries using eye bank-prepared donor tissue was performed between September 2013 and April 2018. DMEK graft characteristics including donor age, preoperative endothelial cell density (ECD), preservation time, death-to-preservation time, and donor diabetes status were analyzed for correlation with rebubble rate and 6-month postoperative ECL. Subgroup analyses of donor age, preoperative ECD, preservation time, death-to-preservation time, preparation-to-surgery time, and diabetes severity were also performed. Statistically significant relationships between donor characteristics and rebubble rate or 6-month postoperative ECL were determined using Pearson correlation, one-way analysis of variance, t test, and χ analysis. The overall rate of rebubble after 857 surgeries performed by 7 surgeons during the study period was 12.6%. There was no significant relationship between postoperative rebubble rate and donor age, preoperative ECD, preservation time, death-to-preservation time, preparation-to-surgery time, or donor diabetes status. The subgroup analysis of these characteristics also yielded no significant relationship with rebubble rate. There was also no significant relationship between 6-month postoperative ECL and analyzed donor factors. Donor characteristics such as higher donor age, lower preoperative ECD (<2500), longer preservation time, and donor diabetes did not increase the rebubble rate or the 6-month ECL after DMEK. These results indicate that common surgeon preferences for donor tissues that are younger, fresher, with higher cell count, and without diabetes do not translate into superior postsurgical outcomes.

Intraoperative fibrin formation during Descemet membrane endothelial keratoplasty

PurposeTo describe Descemet membrane endothelial keratoplasty (DMEK) cases complicated by spontaneous intraoperative fibrin formation. MethodsDMEK surgeries performed at two centers using a standardized technique were reviewed retrospectively for the occurrence of intraoperative fibrin formation. Cases were assessed for recipient medical history, donor age, best spectacle-corrected visual acuity (BSCVA), intraoperative unscrolling time, 6-month endothelial cell loss (ECL), and the course of the mate donor cornea. ResultsIn this review of 868 cases of standardized DMEK surgery with surgical peripheral iridotomy, 32 eyes of 29 patients (3.7%) were complicated by the formation of intraoperative fibrin formation, including 3 patients that developed fibrin in both eyes. Three of the 32 grafts failed (9.4%). None of the mate corneas transplanted (n = 27) developed complications related to fibrin. The donor age ranged from 51 to 75 years and recipient age ranged from 49 to 82 years (median, 66 years). Unscrolling time ranged from 1 to 105 min (median, 15 min). Nine eyes required one rebubble procedure. No eyes had vision-limiting comorbidities, and the 6-month BSCVA was ≥20/40 in all eyes. Six-month ECL ranged from 19% to 73% (median, 44%). ConclusionsWe conclude that fibrin formation during DMEK surgery is an uncommon but important complication that can make graft manipulation more difficult, and may have deleterious effects on endothelial cell density and graft survival.

Endothelium-in Versus Endothelium-out Insertion With Descemet Membrane Endothelial Keratoplasty.

To determine whether graft orientation during insertion affects Descemet membrane endothelial keratoplasty (DMEK) outcomes. This was a retrospective analysis of 754 consecutive DMEK cases performed by 2 experienced surgeons to treat Fuchs dystrophy. Both surgeons used an intraocular lens insertor. One surgeon always inserted the tissue scrolled endothelium outward (group 1, n = 245). The other surgeon tested 3 methods: endothelium-outward scroll configuration (group 2, n = 161), endothelium-inward trifold configuration (group 3, n = 172), and trifold configuration with concurrent use of an anterior chamber maintainer (group 4, n = 176). The main outcome measures were rebubbling rate, regrafting or failure within 6 months, and 6-month endothelial cell loss. The tissue unfolding time from graft insertion to air fill was measured in a subset of 120 cases by 1 surgeon. The rebubbling rates were comparable across groups (ie, 12%, 10%, 10%, and 13% for groups 1, 2, 3, and 4, respectively, P = 0.21). The 6-month graft failure/replacement rates were comparable across groups (ie, 0.8%, 1.2%, 2.3%, and 0.6%, respectively, P = 0.18). Similarly, the 6-month endothelial cell loss did not differ significantly between groups (ie, 28% ± 11%, 30% ± 13%, 28% ± 15%, and 27% ± 13%, respectively, P = 0.019). In the subset analysis, the tissue unfolding time was similar for scroll and trifold configurations (6.0 ± 3.5 vs. 5.4 ± 3.0 minutes, respectively, P = 0.43). The outcomes were similar for endothelium-out and endothelium-in (trifold) insertion methods with DMEK, suggesting that the choice is a matter of surgeon preference.

Intraoperative hyphema in Descemet membrane endothelial keratoplasty alone or combined with phacoemulsification

To identify whether intraoperative hyphema from the peripheral iridotomy during Descemet membrane endothelial keratoplasty (DMEK) is associated with anticoagulant or antiplatelet use, age, combined phacoemulsification, or adverse outcomes. Price Vision Group, Indianapolis, Indiana, USA. Retrospective case series. Data were obtained from consecutive DMEK cases with an intraoperative iridotomy from July 2015 through July 2016. Hyphema was classified as negative or positive (small or large). Associations with possible risk factors and with transplant outcomes were assessed. Of 445 cases, 262 (59%) were negative for hyphema and 183 (41%) were positive. The proportion of patients who used preoperative anticoagulant or antiplatelet medication did not differ significantly with the hyphema classification (negative hyphema 42%, small hyphema 34%, large hyphema 46%) (P=.31). Likewise, recipient age was not a risk factor for hyphema (P=.085). Hyphema was more likely in cases combined with phacoemulsification than in single DMEK procedures (relative risk, 1.5 [95% confidence interval, 1.2-1.9]). Hyphema was not associated with postoperative rebubbling rates (negative hyphema 10.5%, small hyphema 10.3%, large hyphema 8.0%) (P=.33), 6-month endothelial cell loss (mean=29%, P=.19), or 6-month visual acuity (mean=20/25 Snellen in all hyphema groups, P=.98). Preoperative anticoagulant or antiplatelet use was not a significant risk factor for hyphema. The risk for hyphema was increased somewhat when DMEK was combined with cataract surgery. Intraoperative hyphema did not significantly affect the rebubbling rate, endothelial cell loss, or visual acuity outcomes.

Intraoperative S-Stamp Enabled Rescue of 3 Inverted Descemet Membrane Endothelial Keratoplasty Grafts

To report the clinical outcomes of 3 Descemet membrane endothelial keratoplasty (DMEK) grafts, in which an upside down DMEK graft orientation was discovered after SF6 gas insufflation of the anterior chamber and the orientation was then corrected intraoperatively. A total of 371 consecutive DMEK cases using an S-stamp were analyzed and found to include 3 cases in which the DMEK graft was initially elevated with SF6 gas in an upside down orientation, as demonstrated intraoperatively by the S-stamp. In each case, the graft was immediately manipulated into the proper orientation and the rescued case completed using our standard technique. The postoperative complications of these cases were reported and the percentage of endothelial cell loss at 6 months was compared with that of cases in this series without this rare intraoperative complication. All 3 rescued grafts achieved successful recipient corneal clearance and improved vision for the patient. There was no graft failure, rebubble, or rejection in these 3 cases. The average 6-month endothelial cell loss in the 3 initially inverted grafts was 51%, 58.3%, and 67% compared with 31.6% (SD ± 17.4%) in the series at large. Incorporation of a stromal-sided S-stamp has been previously shown to reduce the risk of iatrogenic primary graft failure through the prevention of upside down graft implantation. In these 3 instances, although the stamp did not prevent initial upside down graft elevation, it did allow the surgeon to immediately recognize this rare problem, correct it intraoperatively, and prevent iatrogenic graft failure in each case.

Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty During the Surgeon Learning Curve Versus Descemet Stripping Endothelial Keratoplasty Performed at the Same Time.

PurposeTo compare outcomes after Descemet Membrane Endothelial Keratoplasty (DMEK) and traditional Descemet Stripping Endothelial Keratoplasty (DSEK) during the surgeon’s DMEK learning curve in a prospective, non-randomized, consecutive, interventional case series.MethodsConsecutive patients presenting to the university eye clinics and undergoing endothelial keratoplasty were included. Data including patient demographics, visual acuity, endothelial cell counts and complications were recorded at baseline, as well as 3 and 6 months post-operatively. The primary outcome for this study was BSCVA at 6 months. Pre-specified secondary outcomes included endothelial cell counts and complication rates.ResultsA total of 60 eyes of 42 consecutive patients met inclusion criteria, underwent endothelial keratoplasty, and were included in this analysis. Of these, 18 eyes of 14 patients had DSEK while 42 eyes of 28 patients had DMEK. After controlling for baseline visual acuity, study participants undergoing DMEK had a statistically significant approximately half-line improvement in visual acuity compared with DSEK at 3 months (P=0.05) but not at 6 months (P=0.22). DMEK patients experienced an average of 43% endothelial cell loss compared with 25% in DSEK. There were 5 primary graft failures after DMEK compared with 0 after DSEK and but this was not a statistically significant difference (P=0.09).ConclusionDuring the surgeon’s DMEK learning curve there was some evidence of improved visual acuity outcomes in DMEK. We observed worse 6-month endothelial cell loss among DMEK patients; however this may improve with surgeon experience.

The S-stamp in Descemet Membrane Endothelial Keratoplasty Safely Eliminates Upside-down Graft Implantation

To present 6-month clinical outcomes from a series of 165 consecutive Descemet membrane endothelial keratoplasty (DMEK) procedures before and after the introduction of a novel stromal-sided S-stamp preparation technique that has decreased the incidence of iatrogenic primary graft failure by eliminating upside-down grafts. Retrospective nonrandomized comparative case series. We included 165 consecutive eyes that had undergone DMEK surgery for Fuchs' or pseudophakic bullous keratopathy. These cases were divided into 2 cohorts: the first cohort comprised 31 cases that used unstamped tissue before the S-stamp was introduced, and the second cohort comprised 133 cases after the S-stamp was incorporated into the standardized technique. A single unstamped DMEK case was performed after the introduction of the S-stamp for a total of 32 unstamped cases. Donor materials were prepared at a single eye bank using a standardized technique, which subsequently incorporated the addition of a dry ink gentian violet S-stamp to the stromal side of Descemet membrane. All surgeries were performed at a single clinical site by 5 surgeons (2 attending surgeons and 3 fellows). Two of the 165 DMEK cases were performed for pseudophakic bullous keratopathy (2 cases, 1 in each cohort), and the remaining cases were for Fuchs' endothelial dystrophy. Primary outcome measures were assessed at 6 months and maintained in a prospective institutional review board-approved study. We analyzed the 6-month endothelial cell density, incidence of iatrogenic primary graft failure, upside-down graft implantation, and rebubble events. The S-stamp eliminated upside-down graft implantations (0/133 S-stamped vs 3/32 unstamped) and did not significantly alter 6-month endothelial cell loss (31±17% S-stamped vs 29±14% unstamped; P = 0.62) or frequency of rebubble (17/133 S-stamped vs 1/32 unstamped; P = 0.20). The incorporation of a stromal-sided S-stamp eliminates iatrogenic primary graft failure owing to upside-down implantation of DMEK grafts, without adversely affecting early postoperative complications or 6-month endothelial cell loss.

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

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

Descemet Membrane Endothelial Keratoplasty Combined With Epithelial Debridement and Mitomycin-C Application for Fuchs Dystrophy With Preoperative Subepithelial Fibrosis or Anterior Basement Membrane Dystrophy

The aim of this study was to evaluate the anterior corneal surface regularity and light scattering before and after Descemet membrane endothelial keratoplasty (DMEK) with epithelial debridement and application of mitomycin C in Fuchs dystrophy-affected eyes with preoperative subepithelial fibrosis or anterior basement membrane dystrophy. In this case-control study, a chart review identified 37 eyes with Fuchs dystrophy and anterior corneal changes evident on preoperative slit lamp examination and that underwent DMEK combined with epithelial removal plus mitomycin-C application. These cases were compared with 83 contemporaneous DMEK procedures performed in eyes with Fuchs dystrophy without clinically evident anterior surface problems (controls). The outcome measures were corrected distance visual acuity (CDVA), corneal surface regularity assessed by topography, anterior corneal light scattering by densitometry, endothelial cell loss, and complications. Cases and controls had comparable demographics. Preoperatively, the cases had significantly poorer corneal surface regularity and transparency than did controls (P < 0.0001). Six months postoperatively, the cases achieved comparable CDVA, corneal surface regularity, and transparency as did controls (all P > 0.05), and 77% had a CDVA ≥ 20/25, excluding 2 eyes with preexisting retinal problems. The median 6-month endothelial cell loss was 25% and did not differ significantly between cases and controls (P = 0.31). In 1 case, there was delayed epithelial healing. Even patients with endothelial dysfunction with anterior stromal changes can realize a significant improvement in corneal surface topography and transparency by undergoing combined epithelial removal with DMEK, and this can preclude the need for a subsequent procedure to address residual corneal surface problems or the need for a penetrating keratoplasty.

Prospective Study of Visual Outcomes and Endothelial Survival With Descemet Membrane Automated Endothelial Keratoplasty

To evaluate vision and endothelial cell survival in an initial Descemet membrane automated endothelial keratoplasty (DMAEK) series. This was a prospective nonrandomized study of an initial consecutive series of 40 DMAEK cases, performed with or without concomitant phacoemulsification and intraocular lens implantation. The graft was dissected with a microkeratome. A central 6- to 7-mm big bubble was created to separate endothelium from stroma, and the overlying stroma was excised. The graft was cut to 8.5- to 9.5-mm diameter and inserted with a pull through technique. Eyes were treated for Fuchs endothelial dystrophy, secondary corneal decompensation, or previous failed endothelial transplant. Best spectacle-corrected visual acuity, manifest refraction, pachymetry, and endothelial cell density were assessed. Median best spectacle-corrected visual acuity was 20/30 at 1 month (range: 20/15-20/50), improved from 20/40 (range: 20/25-20/400) preoperatively, excluding 7 eyes (18%) with significant retinal pathology. Rates of 20/20, 20/25, 20/30, and 20/40 vision were 25%, 71%, 89%, and 100%, respectively, at 3 months and 48%, 74%, 93%, and 100%, respectively, at 6 months. Median endothelial cell loss relative to baseline donor cell density was 31% at 6 months. Air was reinjected in 10 eyes (25%) to promote graft attachment, and 2 grafts (5%) failed to clear. DMAEK provided significant improvement in visual acuity and marked reduction in central corneal thickness. DMAEK had a higher rate of postoperative air reinjection than Descemet stripping endothelial keratoplasty and comparable 6-month endothelial cell loss.