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

PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Younger Donor Tissue in Descemet Membrane Endothelial Keratoplasty Surgery: Clinical Outcomes.

PURPOSE: To determine whether using younger donor tissue for Descemet membrane endothelial keratoplasty (DMEK) surgery influences clinical outcomes. METHODS: Scroll tightness, unscrolling time, rebubble rate, and preoperative and 3- and 6-month postoperative endothelial cell density (ECD) and endothelial cell loss (ECL) were compared for 661 DMEK grafts prepared from younger (aged younger than 50 yrs, n = 81) and older donors (aged 50 yrs or older, n = 580) with Student t test, χ2 test, or Mann-Whitney U test. RESULTS: There was no difference in overall unscrolling time (younger donors: 3.1 ± 3.1 min, older donor: 2.9 ± 2.7 min, P = 0.503). Experienced faculty surgeons, compared with fellows, had a significantly lower unscrolling times for both younger donors (2.4 ± 2.3 vs. 4.6 ± 3.9 min, P = 0.002) and older donors (2.5 ± 2.1 vs. 3.7 ± 3.3 min, P <0.001). Rebubble rates were not statistically different between younger (12.3%) and older donors (15.0%, P = 0.527). Three-month ECD was higher in grafts from younger compared with that in those from older donors (2138 ± 442 vs. 1974 ± 470 cells/mm2, P = 0.024). Six-month ECD was similar for younger (1972 ± 509 cells/mm2) and older donors (1947 ± 460 cells/mm2, P = 0.585). There was no difference in 3- or 6-month ECL comparing younger (3-mo: 24.3% ± 13.4%; 6-mo: 31.1% ± 15.2%) with older donors (3-mo: 25.9% ± 15.5%, P = 0.489; 6-mo: 27.8% ± 15.1%, P = 0.231). CONCLUSIONS: DMEK grafts prepared from younger donors exhibited similar unscrolling times, rebubble rates, and 3- and 6-month ECL compared with older donors. Experienced surgeons might begin to accept DMEK grafts from younger donors with confidence.

Descemet Stripping Automated Endothelial Keratoplasty: The influence of preoperative endothelial cell density and triple procedures on grafts at 5 years postoperative.

The purpose is to determine if the preoperative central endothelial cell density (ECD) in triple (phacoemulsification plus intraocular lens implantation plus DSAEK) and non-triple Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) procedures have a relationship with the 5-year postoperative ECD or percent Endothelial Cell Loss (ECL).Out of 986 consecutive DSAEK surgeries for Fuchs dystrophy, 241 eyes had 5-year ECD measurements available. Endothelial cell densities were then evaluated against preoperative ECDs to obtain measures of ECL. Triple and non-triple procedures were isolated and compared independently.One hundred eighty two eyes had undergone a triple procedure and 59 had not. The mean ECD at 5 years was 1560 ±â€Š648 cells/mm for triples and 1483 ±â€Š621 cells/mm for non-triples (P = .42). Endothelial Cell loss was 44.4% ±â€Š21.7% and 44.4% ±â€Š22.0%, respectively for eyes that underwent a triple or non-triple (P = .99). There was a moderate, but significant correlation between preoperative ECD and the ECD at 5 years after DSAEK for both triples (r = 0.39, P < .001), and non-triples (r = 0.32, P = .01), respectively.In Descemets stripping automated endothelial keratoplasty grafts, higher preoperative donor ECD was correlated with higher ECD at 5 years postoperatively but was unaffected by a concurrent cataract surgery in the triple procedure.

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

PURPOSE: To determine whether specific donor characteristics influence postoperative rebubble rate and 6-month endothelial cell loss (ECL) in Descemet membrane endothelial keratoplasty (DMEK). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

The Last 200 Surgeon-Loaded Descemet Membrane Endothelial Keratoplasty Tissue Versus the First 200 Preloaded Descemet Membrane Endothelial Keratoplasty Tissue.

PURPOSE: The purpose of this study was to compare the clinical outcomes from using eye bank-prepared, endothelium-out preloaded Descemet membrane endothelial keratoplasty (DMEK) tissue with those obtained with endothelium-out surgeon-loaded DMEK tissue using the same surgical technique at 1 site. METHODS: This study retrospectively reviewed 400 consecutive cases of DMEK from March 2016 to April 2018. The last 200 cases using surgeon-loaded tissue were compared with the first 200 cases using preloaded tissue. Statistical analysis was performed using the Wilcoxon signed-rank test, binomial logistic regression, Kruskal-Wallis 1-way analysis of variance, Student t test, or Pearson χ tests. RESULTS: Comparing surgeon-loaded versus preloaded DMEK tissue, respectively, no statistical difference was found in the mean 6-month postoperative values for endothelial cell loss (32.9% ± 18.5% vs. 29.9% ± 16.4%, P = 0.31), best corrected visual acuity (20/26 vs. 20/25, P = 0.54), or change in central corneal thickness (-14.4% ± 8.9% vs. -15.6% ± 11.7%, P = 0.43). The mean 1-year endothelial cell loss was also not significantly different (37.6% ± 17.2% vs. 33.2% ± 14.8%, P = 0.07). Overall, the rebubble rate for surgeon-loaded tissue was 17.5% and 12.5% for preloaded tissue, a statistically nonsignificant difference. Operative outcomes for mean tissue scroll tightness (1-4) and tissue unscroll time (minutes) for surgeon-loaded and preloaded tissue were similar between groups (2.4 vs. 2.2, P = 0.12 and 3.5 vs. 3.3 minutes, P = 0.50). CONCLUSIONS: Tissue that is trephinated, stained, and loaded into an injector by the eye bank and then shipped to the surgeon had no difference in clinical outcomes compared with tissue where the surgeon performs these steps. The safety and speed of using preloaded tissue should be considered by DMEK surgeons.

Intraoperative fibrin formation during Descemet membrane endothelial keratoplasty.

PURPOSE: To describe Descemet membrane endothelial keratoplasty (DMEK) cases complicated by spontaneous intraoperative fibrin formation. METHODS: DMEK 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. RESULTS: In 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%). CONCLUSIONS: We 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.

Patent Blue V as an Alternative Stain for DMEK Grafts: Safety, Stain Retention, and Feasibility.

PURPOSE: To determine whether Patent Blue V (PB) can be used as an alternative dye for staining Descemet membrane endothelial keratoplasty (DMEK) grafts. METHODS: DMEK grafts from donor corneas were stained with 2.5% PB for 4 minutes (n = 2), 2.5% PB for 10 minutes (n = 2), or 0.06% trypan blue (TB) for 4 minutes (n = 1). The stain intensity of the grafts was compared initially and at different time points over a 15-minute period of balanced salt solution wash using a grading scale based on a serial dilution series of PB. Three additional grafts were stained with 2.5% PB for 10 minutes and used in mock surgeries to assess stain retention after injection and manipulation in a donor eye model for 25 minutes. To assess the safety of PB, DMEK grafts were prepared from 10 pairs of corneas where one cornea was stained with 0.06% TB for 4 minutes and the mate cornea was stained with 2.5% PB for 10 minutes. The grafts were preloaded and stored for 5 days in Optisol-GS at 2°C to 8°C, and endothelial cell loss was quantified using Calcein-AM staining and FIJI segmentation by 2 masked readers. RESULTS: PB stain intensities were lighter than TB-stained grafts. Grafts stained with 2.5% PB for 10 minutes retained sufficient color for the 25-minute duration of mock surgery. The average endothelial cell loss for PB versus TB grafts was 21.6% ± 5.3% versus 20.2% ± 5.4% (P = 0.202) as determined by reader 1 and 23.6% ± 4.8% versus 21.2% ± 5.8% (P = 0.092) as determined by reader 2. CONCLUSIONS: PB is a viable alternative dye in DMEK grafts for applications where TB may not be available or approved for use.

Reports of Post-keratoplasty Infections for Eye Bank-prepared and Non-Eye Bank-prepared Corneas: 12 Years of Data From a Single Eye Bank.

PURPOSE: To examine postoperative reports of infection rates for eye bank-prepared and non-eye bank-prepared corneas from January 1, 2006 to December 31, 2017, from a single eye bank. METHOD: A retrospective review of reported fungal and bacterial infections with corneal transplant surgeries using corneas distributed by our eye bank was conducted. The reported number of infections for corneas that underwent eye bank preparation (pre-cut and pre-stripped corneas) and for those distributed without eye bank preparation was quantified. The potential association between infection rates in tissue prepared by the eye bank and those in corneas that had no additional eye bank processing was also examined. RESULTS: Four of 17,035 corneas distributed during the study period were associated with fungal infections (1 eye bank-prepared and 3 non-eye bank-prepared corneas) and were attributed to the tissue after investigation by eye bank medical directors. There was no ascending trend of infections reported with eye bank-prepared corneas in the first 3 years (2 of 1054 corneas, 0.19%) compared with that in the last 3 years of the study period (6 of 3500 corneas, 0.17%; P = 0.901) when the eye bank distributed 3 times more prepared corneas than non-eye bank-prepared corneas. A significant increase in the numbers of reported infections for non-eye bank-prepared corneas was observed between these 3-year intervals (0.1% in the first 3 years to 1.58% in the last 3 years; P = 0.001). CONCLUSIONS: Reports of infections remained low despite increased use of eye bank-prepared tissue. These results suggest that factors other than eye bank tissue preparation should be considered when investigating potential sources of pathogen contamination in donor corneas.

Minimizing Endothelial Cell Loss Caused by Orientation Stamps on Preloaded Descemet Membrane Endothelial Keratoplasty Grafts.

PURPOSE: To quantify endothelial cell loss (ECL) caused by orientation stamps on prestripped and preloaded Descemet membrane endothelial keratoplasty (DMEK) grafts, and to examine a method for reducing ECL using a smaller stamp. METHODS: Ten prestripped and 10 preloaded DMEK grafts were prepared with S-stamps. Ten additional preloaded DMEK grafts were prepared with both an S-stamp and a smaller F-stamp in different paracentral areas of the graft. The footprint of each stamp was measured using ink on cardstock. DMEK grafts were stored in viewing chambers filled with 20 mL of Optisol-GS for 3 days at 4°C. ECL was quantified using Calcein-AM staining and FIJI Weka Segmentation. RESULTS: S-stamps on prestripped DMEK grafts contributed an average ECL of 1.1% ± 0.5% (range: 0.6%-2.2%) toward total graft damage, whereas S-stamps on preloaded DMEK grafts contributed approximately twice that amount (average ECL: 2.0% ± 0.7%, range: 1.3%-3.1%, P = 0.004). Overall ECL for prestripped grafts (average: 7.1% ± 3.3%, range: 3.3%-13.7%) and preloaded grafts (average: 11.3% ± 4.2%, range: 6.9%-19.4%) was similar to previous reports. The footprint of the S-stamp was approximately 45% larger than that of the F-stamp. In 10 preloaded grafts marked with both stamps, the S-stamp caused an average ECL of 1.9% ± 0.6% (range: 1.2%-3.2%), whereas the smaller F-stamp caused an average ECL of 1.0% ± 0.2% (range: 0.8%-1.4%, P = 0.0002). CONCLUSIONS: Loss of endothelial cells associated with graft-stamping was greater in preloaded tissue than in prestripped tissue and was less with a smaller F-stamp than with a larger S-stamp. Using a smaller stamp could help minimize ECL in prestripped and preloaded DMEK grafts.

Preloaded Descemet Membrane Endothelial Keratoplasty Donor Tissue: Surgical Technique and Early Clinical Results.

PURPOSE: To describe the technique, advantages, and early complication rates of using Descemet membrane endothelial keratoplasty (DMEK) donor tissue that is prestained and preloaded into an injector at the eye bank and delivered in a storage medium to the surgeon for transplantation 1 to 2 days later. METHODS: A total of 111 eyes with endothelial failure underwent DMEK using donors that were prestripped, prestained, S-stamped, and preloaded into a Straiko modified Jones tube and delivered in an Optisol-filled viewing chamber 1 to 2 days later. Scroll tightness, time to unscroll and center the tissue, postoperative rebubble rate, and graft failure rate were recorded. Endothelial cell density was measured at 3 and 6 months. RESULTS: All tissues remained well stained with easy visualization at the time of surgery (n = 111). The mean scroll tightness was 2.2 (range: 1-4). The mean time to center and unscroll the tissue was 3.5 minutes (range: 0.5-11.25 min). There was no primary graft failure. There were 16 cases with the placement of another bubble postoperatively (with a 14.4% rebubble rate). Of those 16 cases, 2 required a second rebubble. Endothelial cell loss at 3 and 6 months postoperatively was 26.7% (n = 63 eyes) and 30.9% (n = 67 eyes), respectively. CONCLUSIONS: This is the first report of the clinical use of prestained, preloaded tissue for DMEK. The characteristics and handling of the tissue were not different from those of surgeon-loaded tissue. Because punching, staining, and loading the graft intraoperatively is not necessary, the surgery time and risk of damaging donor tissue are reduced when using preloaded tissue.

Partitioning an Artificial Anterior Chamber With a Latex Diaphragm to Simulate Anterior and Posterior Segment Pressure Dynamics: The "DMEK Practice Stage," Where Surgeons Can Rehearse the "DMEK Dance".

PURPOSE: To present a novel apparatus for simulating the anterior and posterior segment pressure dynamics involved in executing Descemet membrane endothelial keratoplasty (DMEK) surgery when using a chamber-shallowing technique. METHODS: An artificial anterior chamber (AAC), 18-mm trephine, latex glove, two 3-mL syringes, and one donor cornea comprising an intact corneoscleral cap from which a DMEK tissue was peeled and punched are required for the model. After making the corneal incisions with the corneoscleral cap mounted on the AAC in the usual fashion, the corneoscleral cap is remounted onto the dried AAC over an 18-mm latex diaphragm. The space between the latex diaphragm and the cornea is filled with saline to pressurize the anterior chamber, and the posterior segment is pressurized with air from a syringe. The resulting apparatus comprises a posterior segment and anterior chamber that exert pressure on each other by way of a distensible latex diaphragm. RESULTS: A novice and experienced DMEK surgeon and 2 eye bank technicians were able to assemble the apparatus and perform the routine steps of a DMEK procedure, including maneuvers that require shallowing the anterior chamber and lowering its pressure. Only one cornea was required per apparatus. CONCLUSIONS: We present a novel in vitro model of the human eye that more closely mimics the anterior and posterior segment pressure dynamics of in vivo DMEK surgery than average human and animal cadaveric globes. The model is easy to assemble, inexpensive, and applicable to a range of teaching environments.

Light scattering measurements in electron-beam sterilized corneas stored in recombinant human serum albumin.

Irradiated corneal tissues have been used for a variety of ophthalmic procedures including glaucoma drainage device covers and lamellar grafts. The maintenance of corneal clarity is important, as light obstructions resulting from processing or long-term storage of irradiated corneas may negatively affect vision and postoperative cosmesis. It has been reported that corneal tissues can be preserved in human serum albumin (HSA), however, the clarity of corneas after long-term storage in HSA has not been well described. Furthermore, the use of donor-pooled serum increases the risk for transmission of blood-borne diseases and may induce an immune response in the recipient. Here, we examined changes in corneal clarity due to electron-beam (e-beam) irradiation and storage in a recombinant human serum albumin (rHSA). Dark-field microscopy was employed to examine the light scattering effects of fresh and irradiated corneas. Compared to measurements taken prior to tissue preparation and e-beam treatment, irradiated corneas showed an average 2.6% increase in light scattering (P = 0.002). Irradiated corneas stored in rHSA at room-temperature for 20 months showed an average increase of 11.6% light scattering compared to fresh corneas (P â‰ª 0.01), but did not negatively affect the visualization of printed text, and were deemed suitable for transplant use. Therefore, the slight increase in cornea light scattering, and resulting reduction in corneal clarity, after e-beam treatment and long-term storage in rHSA may not be clinically significant. These results suggest that e-beam sterilized corneal grafts may be used as an alternative to fresh tissue for certain ophthalmic applications.

Descemet Membrane Endothelial Keratoplasty in Eyes With Previous Laser Refractive Surgery: Outcomes and Complications.

PURPOSE: To evaluate the refractive predictability and efficacy of Descemet membrane endothelial keratoplasty (DMEK) for patients with previous laser refractive surgery. METHODS: We retrospectively reviewed our cohort of endothelial keratoplasty surgical cases. We identified 21 eyes that underwent laser-assisted in situ keratomileusis (n = 17) or photorefractive keratectomy (n = 4) and were treated with DMEK for endothelial failure. Patients were analyzed preoperatively and at 6 months postoperatively for changes in visual acuity, refraction, and corneal topography. RESULTS: Six months after surgery, eyes significantly improved to a mean best-corrected visual acuity of 20/23 (P < 0.001). Mean astigmatism amplitude changed from 1.13 ± 0.96 preoperatively to 0.92 ± 0.51 diopters postoperatively (P = 0.28). However, shifts in the axis of corneal astigmatism ranged from 1 to 70 degrees, with 6 eyes (30%) showing an axis shift of more than 30 degrees. Spherical equivalents in nontriple procedures remained unchanged (n = 16; P = 0.69) at 6 months. CONCLUSIONS: DMEK and DMEK triple procedures are predictable in patients with previous refractive surgery achieving good visual results. However, refraction after the use of toric intraocular lenses may be unpredictable because of the variability in changes of the magnitude and axis of corneal astigmatism; we recommend extreme caution in the use of the toric intraocular lens in this group of patients and proper counseling for possible individual postoperative residual astigmatism.

Prestained and Preloaded DMEK Grafts: An Evaluation of Tissue Quality and Stain Retention.

PURPOSE: To examine endothelial cell damage and stain retention of prestained preloaded Descemet membrane endothelial keratoplasty (DMEK) grafts. METHODS: DMEK grafts were stained with trypan blue or left unstained before loading into a Straiko modified Jones tube. A protocol to stain preloaded grafts inside the modified Jones tube and resulting cell loss was also examined. Endothelial cell loss was determined by vital dye staining after 3 days of cold storage and compared between the 3 groups. Eight additional grafts were stained, loaded, and shipped from Oregon to New York to assess stain stability. Stain retention and the ability to successfully inject and open these "prestained preloaded" grafts in cadaveric donor eyes were also evaluated. RESULTS: Unstained preloaded DMEK grafts showed an overall cell loss of 15% ± 3% [95% confidence interval (CI), 11%-18%]. Prestained grafts had a cell loss of 16% ± 4% (95% CI, 10%-22%) and were not significantly different from unstained grafts (P = 1). Grafts stained while inside the modified Jones tubes had an average cell loss of 18% ± 2% (95% CI, 16%-20%, Pprestained = 0.15, Punstained = 0.09). All grafts shipped across the country and examined 3 days after preparation showed a decrease in stain intensity but were still deemed suitable for transplantation by an experienced DMEK surgeon. CONCLUSIONS: It is possible to prestain and preload DMEK grafts without inducing additional endothelial cell loss. Consideration should be given to the interval between staining and surgery because stain can fade.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Evaluation and Quality Assessment of Prestripped, Preloaded Descemet Membrane Endothelial Keratoplasty Grafts.

PURPOSE: To determine graft quality and feasibility of Descemet membrane endothelial keratoplasty (DMEK) grafts that are prestripped and preloaded into injectors by eye bank technicians before shipping to surgeons. METHODS: DMEK grafts (n = 31) were prepared from donor corneas and preloaded into Straiko Modified Jones tubes and set inside viewing chambers filled with 20 mL of Optisol-GS. Preloaded grafts were evaluated using specular microscopy and slit-lamp biomicroscopy. Endothelial cell loss (ECL) was captured by vital dye staining and quantified using FIJI. A subset of preloaded tissues was subjected to a shipping validation and 5-day storage assay. Fourteen additional DMEK grafts (not preloaded) were examined to quantify damage resulting from prestripping alone. RESULTS: Specular microscopy was able to be performed for all preloaded tissues. Average ECL for preloaded tissues quantified by vital dye staining and FIJI after overnight storage was 16.8% ± 5.9%, and differed from slit-lamp ECL estimation by an average of 5.3% ± 3.6%. The average damage caused by prestripping alone was 9.3% ± 5.9%, and it was significantly less than that of preloaded tissues (P < 0.01). Average ECL for preloaded tissues subjected to round-trip shipping events was 18.5% ± 12.4%, and ECL for tissues stored at 4°C for 5 days after preloading was 13.1% ± 9.5%. CONCLUSIONS: It is possible to prepare, evaluate, and ship DMEK grafts loaded inside a glass carrier and viewing chamber. The ability to evaluate tissues after processing allows for adherence to the Eye Bank Association of America Medical Standards, and for surgeons to receive the most accurate tissue information.

Astigmatism Correction With Toric Intraocular Lenses in Descemet Membrane Endothelial Keratoplasty Triple Procedures.

PURPOSE: To report the clinical efficacy of astigmatism correction with toric intraocular lenses (IOLs) in patients undergoing the Descemet membrane endothelial keratoplasty (DMEK) triple procedure and to evaluate the accuracy of the correction. METHODS: Fifteen eyes of 10 patients who received cataract extraction, toric IOL placement, and DMEK surgery for Fuchs corneal dystrophy and cataracts were evaluated. The cylinder power of toric IOLs was determined by an online toric calculator with keratoscopy measurements obtained using Scheimpflug corneal imaging. Prediction errors were assessed as a difference vector between the anticipated minus postoperative residual astigmatism. RESULTS: At 10.1 ± 4.9 months postoperatively, 8/13 (61.5%) of eyes achieved uncorrected distance visual acuity better than 20/40. Mean best spectacle-corrected distance visual acuity (logMAR) improved from 0.21 ± 0.15 preoperatively to 0.08 ± 0.12 postoperatively (P < 0.01). The magnitude of refractive astigmatism was also significantly decreased from 2.23 ± 1.10 D (range 0.75-4.25 D) preoperatively to 0.87 ± 0.75 D (range 0.00-3.00 D) postoperatively (P < 0.01). In 1 eye with rotational misalignment by 43 degrees, we found no improvement of astigmatism. The prediction error of astigmatism at the corneal plane was 0.77 ± 0.54 D (range 0.10-1.77 D). Four eyes with preoperative "with-the-rule" corneal astigmatism had postoperative "against-the-rule" refractive astigmatism. CONCLUSIONS: For patients with Fuchs corneal dystrophy and cataracts, use of toric IOLs might be a valuable option in triple DMEK surgery. Additionally, care should be taken to prevent excessive IOL rotation.

Corneal Astigmatism Stability in Descemet Membrane Endothelial Keratoplasty for Fuchs Corneal Dystrophy.

PURPOSE: To calculate the magnitude and angle of the shift in corneal astigmatism associated with Descemet membrane endothelial keratoplasty (DMEK) surgery to determine the feasibility of concurrent astigmatism correction at the time of DMEK triple procedures. DESIGN: Retrospective study. METHODS: Forty-seven eyes that previously underwent the DMEK procedure for Fuchs endothelial corneal dystrophy and that had more than 1.0 diopter (D) of front corneal astigmatism preoperatively were identified. All DMEK surgeries used a clear corneal temporal incision of 3.2 mm. Surgically induced astigmatism (SIA) was evaluated 6 months postsurgery with vector analysis using Scheimpflug image reading. RESULTS: We did not find a difference between pre- and postoperative magnitude of front astigmatism (P = 0.88; paired t test). The magnitude of the SIA front surface was 0.77 ± 0.63 D (range, 0.10-3.14 D). The centroid vector of the SIA front surface was 0.14 at 89.3°. A hyperopic corneal power shift was noted in both the front surface by 0.26 ± 0.74 D (range, 0.45-3.05 D) (P = 0.018; paired t test) and back surface by 0.56 ± 0.55 D (range, 0.25-2.40 D) (P < 0.01; paired t test). CONCLUSIONS: DMEK surgery induces minimal amounts of corneal astigmatism that is a with-the-rule shift associated with a temporal clear corneal incision. The stability of these data from preop to postop supports the plausibility of incorporating astigmatism correction with the cautious use of toric intraocular lenses for patients with Fuchs corneal dystrophy and cataract.

Descemet Membrane Endothelial Keratoplasty (DMEK) Tissue Preparation: A Donor Diabetes Mellitus Categorical Risk Stratification Scale for Assessing Tissue Suitability and Reducing Tissue Loss.

PURPOSE: This study assessed a novel diabetes mellitus (DM) rating scale in relation to its utility in reducing Descemet membrane endothelial keratoplasty (DMEK) tissue preparation failure. METHODS: A 5-point DM rating scale was defined, in which 1 demonstrated relatively good health associated with DM and 5 represented comorbidities associated with DM. A chart review from consecutive donors who had at least 1 tissue prepared for DMEK was performed. Using the donor profile, the first tissue processed from each donor was categorized according to the DM severity and if the tissue passed or failed the DMEK preparation. Failure rates per rating group were evaluated using logistic regression and odds of preparation failure. RESULTS: A total of 125 tissues prepared for DMEK were categorized based on the defined DM rating scale. Of these, 9 tissues were rated 1 (11.1% failure), 25 were rated 2 (0% failure), 31 were rated 3 (6.5% failure), 24 were rated 4 (16.7% failure), and 36 were rated 5 (30.6% failure). The odds ratios were significant for tissues rated as 5 and 3 (P < 0.05). No other rating categories were found to influence the odds of failure. A χ test comparing categories of low risk (1-3) and high risk (4-5) was also performed (P = 0.001). CONCLUSIONS: The DM rating scale does seem to stratify the risk of preparation failure associated with the severity of DM and associated comorbidities. Inclusion of some diabetic donors for the preparation of DMEK grafts may be warranted given proper screening of the donor history and application of the rating scale.

Relationship Between Tissue Unscrolling Time and Endothelial Cell Loss.

PURPOSE: To assess the relationship between intraoperative unscrolling time of the donor Descemet membrane endothelial keratoplasty (DMEK) tissue and 6-month postoperative endothelial cell loss (ECL), and to determine whether donor age, scroll tightness, and the presence of an S stamp are related to unscrolling time. METHODS: Ninety-three consecutive uncomplicated DMEK surgeries performed on eyes with Fuchs endothelial dystrophy using our standardized technique (ie, prestripped tissue with or without a premarked S stamp from our eye bank, overstripping the recipient, Straiko glass injector, no-touch tap technique, and bubble of 20% SF6 gas) were evaluated. Intraoperative unscrolling times and 6-month endothelial cell densities were measured and analyzed. RESULTS: Sixty-nine cases comprised the study cohort. The median unscrolling time was 4 minutes (range: 0.8-17.5 minutes), and the median ECL was 26.9% (range: -4.3% to 80.0%). There was no relationship between unscrolling time and ECL at 6 months by the Pearson correlation coefficient (r = -0.02, P = 0.89). Younger donor age, tighter scrolls, and absence of an S stamp had no correlation with longer unscrolling times (all P > 0.05). Only 2 of 4 cases of iatrogenic primary graft failure had unscrolling times available for analysis; in this limited sample, there was no association between iatrogenic primary graft failure and unscrolling time. CONCLUSIONS: Once the DMEK tissue is safely in the anterior chamber, surgeons need not rush the "DMEK dance" because longer unscrolling times may not endanger the endothelium.