Average Endothelial Cell Density Research Articles

Culturing Discarded Peripheral Human Corneal Endothelial Cells From the Tissues Deemed for Preloaded DMEK Transplants.

To investigate if the peripheral corneal endothelium that is discarded after the preparation of preloaded Descemet membrane endothelial keratoplasty (DMEK) grafts for transplantation could be successfully used for corneal endothelial cell culture. Complete Descemet membrane-endothelial complex (11.00 mm) was peeled from research-grade tissues (n = 15). The periphery (2.75 mm) of clinical-grade tissues (n = 15) deemed for preloaded DMEK transplants was gently peeled and preserved for 48 hours in tissue culture media, followed by centrifugation at 1000 rpm for 5 minutes. After enzymatic digestion, the cells from each group were plated in 2 different wells of an 8-well chamber slide. Media were refreshed and the confluence rate was monitored every alternate day. Live/dead staining and the expression of ZO-1, Tag1A3, Tag2A12, and Ki-67 markers were used to assess the viability, morphology, tight-junctions, cell area, and number of proliferative cells. The Wilcoxon and Student's t test were applied, where P < 0.05 was deemed statistically significant. Average endothelial cell density at confluence was 2,352 cells/mm2 from complete endothelium and 2,510 cells/mm from peripheral endothelium (P = 0.0351). The confluence rate (%), hexagonality (%), polymorphism (%), cell area (μm), and Ki-67 positivity (%) did not differ between both groups (P > 0.05). All the antibodies were expressed in both groups at confluence. The discarded peripheral endothelial cells obtained after preparing a preloaded DMEK graft for clinical application has a huge reservoir of healthy endothelial cells having proliferative potential. Using these discarded tissue pieces from donor tissues will significantly increase the primary source of healthy donor endothelial cells for regenerative treatments, which are otherwise difficult to obtain.

Corneal thickness and endothelial cell density in children with type 1 diabetes mellitus.

BACKGROUND:The aim of this study was to detect the effect of diabetes on the corneal endothelium in patients of Type 1 diabetes in the pediatric age group and to compare them with age-matched controls. Further, it was proposed to establish any correlation between these changes and risk factors of diabetes, viz., age, duration of diabetes, and hemoglobin A1c (HbA1c) values.MATERIALS AND METHODS:This was a prospective cross-sectional study. Fifty children with Type 1 diabetes, between the ages of 7 and 17 years (average, 12.16 ± 2.63 years), and fifty healthy age-matched controls (average 12.28- ±3.00 years) were examined. The central corneal thickness (CCT) and endothelial cell density (CD) were assessed by the Topcon SP-1P specular microscope. The duration of diabetes (average, 3.91 ± 1.65 years) and the HbA1c values (average, 10.92 ± 2.28) were also noted.RESULTS:The average CCT in the diabetics was 525.16 ± 33.14 μ and in the controls 513.44 ± 29.46 μ. This was significantly higher (P = 0.015). The average endothelial CD in the diabetics was 3039.64 ± 292.84 cells/mm2 and in the nondiabetics 3360.41 ± 268.04 cells/mm2. This was significantly lower (P < 0.001). A significant correlation was found between the endothelial CD and age of the diabetic patients (P = 0.008). However, there was no significant correlation between the endothelial CD and the CCT with either duration of diabetes or HbA1c.CONCLUSIONS:A significant decrease in the endothelial CD and increase in the CCT occurs in children and adolescents with Type 1 diabetes. With the age of the diabetic patients, the endothelial CD significantly reduces. However, duration of diabetes and HbA1c do not affect these values.

Complications and outcomes of descemet stripping automated endothelial keratoplasty with artisan aphakia intraocular lens implantation

To evaluate the complications and outcomes of descemet stripping automated endothelial keratoplasty (DSAEK) combined with artisan aphakia intraocular lens (IOL) implantation in severely damaged eyes without capsular support. DSAEK combined with artisan iris claw IOL implantation was performed on 29 eyes. All eyes were of abnormal structure due to complications from prior intraocular surgeries and ocular trauma. Ocular complications observed included graft dislocations, high intraocular pressure (IOP), IOL dislocations, macular edema and hyphema. Best corrected visual acuity (BCVA), IOP and mean central endothelial cell density (ECD) were recorded. Thirteen eyes had a history of ocular trauma, 10 eyes had an anterior chamber IOL, 16 eyes had prior vitrectomy. The iris was abnormal in 22 cases. Graft dislocation occurred in 5 (17.2%) of 29 eyes. IOL dislocation occurred in 2 eyes (6.9%). High IOP was found in 9 eyes and was controlled with treatment. The preoperative mean BCVA was 20/286. The 6mo postoperative mean BCVA was 20/42. The average center ECD was 1965.3 cells/mm2 at 6mo, and the rate of the donor cell loss was 34.7%. DSAEK combined with artisan aphakia IOL implantation is an alternative option for resolving endothelial and lens disorders in aphakic eyes without capsular support. However, it should be performed cautiously for eyes with severe iris defects.

Endothelial assessment of donated tectonic corneas: a viable option for posterior lamellar transplantation.

Donated corneas are classified as tectonic if there are defects within any layers of the cornea which would prevent a satisfactory visual outcome after transplantation. This study aimed to evaluate whether some tectonic corneas have sufficient endothelial characteristics to allow their use in posterior lamellar keratoplasty, and explored their reclassification for use in this sight-improving procedure. A retrospective review of all corneal tissues preserved by the Sorocaba Eye Bank from January to April of 2014 was performed. All donated corneas classified as tectonic were included. Endothelial tissue was defined as healthy and viable for posterior lamellar keratoplasty if endothelial cell density was ≥2000 cells/mm2. Additional parameters analyzed included Descemet folds and stretch marks, loss of endothelial cells, corneal endothelial polymegathism/ pleomorphism, pseudo-guttata, and reflectivity. During the study period, 2,847 corneas were preserved, of which 423 (14.85%) were classified as tectonic. Of these, 87 (20.56%) were reported as having endothelial viability and were included in the posterior lamellar keratoplasty group. Average corneal endothelial cell density of this group was 2,471 SD ± 256 cells/mm2 (range 2012-2967 cells/mm2). A significant number of corneas classified as tectonic showed endothelial viability and were included in the posterior lamellar keratoplasty group (20.56%). Despite stromal and/or epithelial alterations, these corneas could have been potentially distributed for posterior lamellar transplantation to improve vision, thus reducing the corneal transplantation waiting period. This study highlights how corneal tissue reclassification could increase the potential amount of corneal tissue available for optical transplantation.

Comparaison des résultats anatomiques et fonctionnels à 12 mois d’une série de kératoplasties lamellaires profondes assistées au laser femtoseconde Z6 versus trépanation manuelle pour kératocônes sévères

The management of severe keratoconus requires corneal transplantation, for which the gold standard is deep anterior lamellar keratoplasty (DALK), preserving the healthy Descemet's membrane and endothelium. The safety and reproducibility of corneal cuts have been improved by the evolution of femtosecond lasers in refractive surgery, and femtosecond laser in DALK would seem to provide the same advantages over the manual method. In our retrospective study, we compare functional and anatomical results of femtosecond assisted DALK versus manual trephination DALK in patients with keratoconus in stage 4of the Krumeich classification. It is a retrospective study including all patients with stage 4keratoconus who underwent femtosecond laser assisted DALK between November 2012and November 2015in Nantes hospital. We compared those patients to a group of patients who underwent manual DALK in the same period, paired by age and maximal keratometry. We assessed visual acuity, pachymetry, endothelial cell density (specular microscopy), and keratometry before surgery and at 4, 8and 12months of follow-up. Laser settings and intraoperative complications were recorded. Nineteen patients underwent surgery by femtosecond assisted DALK, 6women and 12men with average age 30.2±10.8years at transplantation. They were paired with a group of 17patients who underwent manual DALK in order to compare results. Before surgery, mean visual acuity in the femtosecond group was 0.90logMAR versus 0.89logMAR in the manual group, showing no statistically significant difference (P=0.96). Both groups were similar in terms of preoperative age, mean keratometry, pachymetry and endothelial cell density. Average visual acuity post-surgery was 0.27, 0.26; and 0.14logMAR for femtosecond DALK versus 0.27, 0.17et 0.25for manual DALK at 4, 8and 12months follow-up, respectively showing no statistically significant difference. After surgery, at 4, 8and 12months, mean pachymetry was similar in both groups, and average endothelial cell density was 2390cells/mm2in femtoDALK versus 2531cells/mm2in manual DALK at 12months of follow-up, showing no statistically significant difference (P=0.5726). The rate of Descemet's membrane microperforations during the procedure was low and similar for both groups. Our study allows for a 12month follow-up, with assessment of visual recovery, anatomical result and endothelial safety in a sample of 19femtosecond laser assisted DALK with no statistical significant difference versus the manual trephination group. Femtosecond laser allows for increased reproducibility of the DALK procedure without reducing adverse effects during surgery. Femtosecond laser seems to improve the technique of the DALK procedure, and future developments could improve the reproducibility of DALK even further. A medical economics study would be necessary to determine the cost effectiveness of femtosecond laser assisted DALK.

Ophthalmic features of spinocerebellar ataxia type 7.

PurposeTo analyze the relation between ophthalmologic and motor changes in spinocerebellar ataxia type 7 (SCA7).Patients and methodsThis was a case series study. Sixteen SCA7 patients underwent a comprehensive ophthalmic examination, including ocular extrinsic motility testing, color vision test, and optical coherence tomography of the optic nerve and macula. Changes in the corneal endothelium, electroretinographic patterns, and a complete neurologic evaluation using the Scale for the Assessment and Rating of Ataxia (SARA) were evaluated. Correlations of endothelial cell density (ECD) with number of CAG repetitions and the SARA scores were estimated.ResultsAll patients showed various degrees of visual impairment mainly due to macular deterioration. Notably, they also presented decreased ECD. Pairwise correlations of ECD with number of CAG repeats and severity of motor symptoms quantified with the SARA scores were inverse (r=-0.46, P=0.083 and r=-0.64, P=0.009, respectively). Further analyses indicated an average ECD decrease of 48 cells/mm2 (P=0.006) per unit of change on the number of CAG repeats, and of 75 cells/mm2 (P=0.001) per unit of change on the SARA scores.ConclusionsThe results agree with previous ophthalmological findings regarding the widespread effect of SCA7 mutation on the patient's visual system. However, the results also show a significant negative correlation of decreased ECD with both CAG repetitions and SARA scores. This suggests that motor systems could degenerate in parallel with visual systems, although more research is needed to determine whether the degeneration is caused by the same mechanisms.

Comparison of 12-month anatomic and functional results between Z6 femtosecond laser-assisted and manual trephination in deep anterior lamellar keratoplasty for advanced keratoconus

The management of severe keratoconus requires corneal transplantation, for which the gold standard is deep anterior lamellar keratoplasty (DALK), preserving the healthy Descemet's membrane and endothelium. The safety and reproducibility of corneal cuts have been improved by the evolution of femtosecond lasers in refractive surgery, and femtosecond laser in DALK would seem to provide the same advantages over the manual method. In our retrospective study, we compare functional and anatomical results of femtosecond-assisted DALK versus manual trephination DALK in patients with keratoconus in stage 4 of the Krumeich classification. It is a retrospective study including all patients with stage 4 keratoconus who underwent femtosecond laser-assisted DALK between November 2012 and November 2015 in Nantes university medical center. We compared those patients to a group of patients who underwent manual DALK in the same period, paired by age and maximal keratometry. We assessed visual acuity, pachymetry, endothelial cell density (specular microscopy), and keratometry before surgery and at 4, 8 and 12months of follow-up. Laser settings and intraoperative complications were recorded. Nineteen patients underwent surgery by femtosecond-assisted DALK, 6women and 12men with average age 30.2±10.8years at transplantation. They were paired with a group of 17patients who underwent manual DALK in order to compare results. Before surgery, mean visual acuity in the femtosecond group was 0.90logMAR versus 0.89logMAR in the manual group, showing no statistically significant difference (P=0.96). Both groups were similar in terms of preoperative age, mean keratometry, pachymetry and endothelial cell density. Average visual acuity post-surgery was 0.27; 0.26; and 0.14logMAR for femtosecond DALK versus 0.27; 0.17et 0.25 for manual DALK at 4, 8 and 12months follow-up respectively, showing no statistically significant difference. After surgery, at 4, 8 and 12months, mean pachymetry was similar in both groups, and average endothelial cell density was 2390cells/mm2 for femto DALK versus 2531cells/mm2 for manual DALK at 12months of follow-up, showing no statistically significant difference (P=0.5726). The rate of Descemet's membrane microperforations during the procedure was low and similar for both groups. Our study allows for a 12-month follow-up, with assessment of visual recovery, anatomic result and endothelial safety in a series of 19femtosecond laser-assisted DALK with no statistical significant difference versus the manual trephination group. Femtosecond laser allows for increased reproducibility of the DALK procedure without reducing adverse effects during surgery. Femtosecond laser seems to improve the technique of the DALK procedure, and future developments could improve the reproducibility of DALK even further. A medical economics study would be necessary to determine the cost-effectiveness of femtosecond laser-assisted DALK.

Endothelial cell loss in penetrating keratoplasty, endothelial keratoplasty, and deep anterior lamellar keratoplasty.

PURPOSE:To compare endothelial cell density (ECD) loss rates in penetrating keratoplasty (PKP), Descemet's stripping automated endothelial keratoplasty (DSAEK), and deep anterior lamellar keratoplasty (DALK).DESIGN:Single-center, multiple-surgeon, retrospective cohort study.MATERIALS AND METHODS:Patients who received PKP, DSAEK, or DALK from 2009 to 2014 were analyzed (68 vs. 38 vs. 11 patients, respectively). We excluded patients with therapeutic PKP or regraft, infection, endothelial rejection, or uncontrolled glaucoma. Only clear grafts and initial ECD more than 1000 cell/mm2 were included in the study. The main outcome was ECD loss rate. The follow-up time period was divided into five subgroups: 0–1.5 months, 1.5–6 months, 6–12 months, 12–24 months, and longer than 24 months.RESULTS:Average ECD loss rate (cell/mm2/month) declined in all three groups (PKP group: −561.5, −113.2, −36.6, −31.4, and −53.7; DSAEK group: −686.4, −68.3, −21.8, −14.4, and −5.1; DALK group: −576.5, −68, −23.7, 5.9, and 18.3). Although DSAEK group showed faster ECD loss rate in the early postoperative period, it became slower compared to the PKP group within the postoperative 6th month and demonstrated significant difference within 2 years. No ECD loss developed in the DALK group after the 1st postoperative year; this was significantly different from the PKP group.CONCLUSIONS:Although ECD loss rate in the DSAEK group was initially larger than that in the PKP group, the DSAEK group possessed better long-term endothelial cell survival rate. The DALK group had a lower ECD loss rate than that of the other groups and maintained a stable ECD at 1 year after surgery.

Analyses of Factors Affecting Endothelial Cell Density in an Eye Bank Corneal Donor Database.

To analyze the factors affecting central corneal endothelial cell density (ECD) in an eye bank corneal donor database. The Lion's Eye Institute corneal donor database consisting of 18,665 donors (34,234 corneas) aged 20 years or older was analyzed. In particular, differences in the ECD based on age, sex, race, prior ocular surgery, a history of systemic diseases, and smoking were investigated. Furthermore, risk factors for donor cell count inadequacy (defined here as ECD less than 2000/mm) were identified. ECD decreased with age. Regarding race, the average ECD of African American donors was higher than those of white or Hispanic donors. A history of diabetes mellitus (DM) and ocular surgery were associated with a lower ECD. Donor medical history of hypertension, glaucoma, depression, dementia, Parkinson disease, hyper- or hypothyroidism, or smoking did not seem to affect the ECD. The risk factors for donor cell count inadequacy, based on binary logistic regression analyses were advanced age [65-74 years yielded an odds ratio of 17.8; confidence interval (CI), 10.6-29.8; P < 0.001; and 75-99 years yielded an odds ratio of 24.6 (CI, 14.5-41.61; P < 0.001) when compared with 20-34 years], cataract surgery (odds ratio, 4.3; CI, 4.0-4.8; P < 0.001), and DM (odds ratio, 1.2; CI, 1.1-1.3; P = 0.001). Age, race, ocular surgery (cataract and refractive), and DM seem to significantly affect donor corneal ECD. Of these variables, age, a history of cataract surgery, and DM were found to be the greatest risk factors for inadequate donor cell density (less than 2000/mm).

Clinical observation on the corneal endothelium transplantation for the treatment of corneal decompensation

Objective To investigate the clinical effect of corneal endothelium transplantation for corneal decompensation. Methods Six eyes of 6 patients of secondary corneal decompensation after cataract surgery were enrolled. They had undergone corneal endothelium transplantation. The 13~14 mm diameter of deep lamellar corneal endothelial implant was separated with cornea knife, and it was transplanted into receptor anterior chamber. Results The six eyes were followed up for over 6 months. The cornea was transparent in all cases, and the endothelial implant attached well. The visual acuity was improved from preoperative FC-0.05 to 0.12-0.3 six months after surgery. The average corneal endothelial cell density increased significantly from ≤656/mm2 preoperatively to 1889-2456/mm2 postopevatively. Conclusion The corneal endothelium transplantation is an effective method for the treatment of corneal decompensation. Key words: Corneal endothelium transplantation; Corneal decompensation

Comparison of human corneal cell density by age and corneal location: an in vivo confocal microscopy study.

BackgroundPeripheral and central regions of the cornea are optically different and have different repair capacity and pathology. For this reason, we characterized the cellular morphology and quantified the cell density of the central and peripheral regions of the cornea with age.MethodsEighty healthy subjects were enrolled in the study and divided into four groups according to age: A (0–19 years), B (20–39 years), C (40–59 years), and D (>60 years). In vivo confocal microscopy was used to measure the following parameters for the central and peripheral regions of the cornea: average cellular density and area of the superficial and basal epithelium; average density of the anterior and posterior keratocytes; average endothelial cell density and cellular area; percentage of hexagonal endothelial cells.ResultsStatistically significant differences between the central and peripheral cornea were observed for the cellular density of basal epithelial cells in group A. The density of keratocytes in the anterior stroma was significantly greater in the central region compared with the peripheral region in group B and group C. The percentage of hexagonal cells in the endothelial layer was significantly greater in the central region compared with the peripheral region. Age-related changes were found in peripheral basal epithelial cell density, central and peripheral endothelial cell density, and the percentage of hexagonal endothelial cells.ConclusionBoth similarities and differences in morphology of the central and peripheral regions of the transparent cornea were observed. These observations would provide a histological basis for further studies to define its regional pathological mechanisms.

Retropupillary iris-claw intraocular lens in ectopia lentis in Marfan syndrome.

ObjectiveTo report visual outcomes, complication rate, and safety of retropupillary iris-claw intraocular lens (ICIOL) in ectopia lentis in Marfan syndrome (MFS).DesignRetrospective study.MethodsSix eyes of three MFS patients with ectopia lentis underwent surgery for subluxation lens and retropupillary ICIOL implantation from October 2014 to October 2015 at the Department of Ophthalmology, Santa Maria Hospital in Lisbon, Portugal. Demographics, preoperative and postoperative best-corrected visual acuity (BCVA), and intraocular pressure were evaluated. Endothelium cell count was assessed using specular microscopy; anterior chamber depth was measured using Pentacam postoperatively; and intraocular lens position was viewed by ultrasound biomicroscopy. All patients were female; mean age was 20±14.264 years (range: 7–38 years).ResultsThe average follow-up period was 6.66 months (range: 4–16 months). Preoperative BCVA was 0.568±0.149 logMAR units, and postoperative BCVA was 0.066±0.121 logMAR units. The mean BCVA gain was −0.502±0.221 on the logMAR scale. Postoperative average astigmatism and intraocular pressure were 1.292±0.697 mmHg (range: 0.5–2.25 mmHg) and 16 mmHg (range: 12–18 mmHg), respectively. The average endothelial cell density decreased from 3,121±178 cells/mm2 before surgery to 2,835±533 cells/mm2 after surgery (measured at last follow-up visit) and in the last follow-up, representing an average endothelial cell loss of 9.16%. Mean anterior chamber depth was 4.01 mm (±0.77 mm), as measured by Pentacam. No complications were found intra- or postoperatively in any of the six studied eyes.ConclusionRetropupillary ICIOL implantation is a safe and effective procedure in the treatment of aphakia in MFS eyes, without capsular support after surgery for ectopia lens. The six eyes that underwent lensectomy and retropupillary ICIOL implantation have had excellent visual outcomes with no complications so far.

Single-Pass Microkeratome System for Eye Bank DSAEK Tissue Preparation: Is Stromal Bed Thickness Predictable and Reproducible?

To evaluate the predictability and reproducibility of stromal bed thickness for single-pass donor Descemet stripping automated endothelial keratoplasty (DSAEK) tissue preparation, using the ML7 Microkeratome Donor Cornea System (Med-logics Inc, Athens, TX). In this retrospective chart review of 256 consecutive corneal tissue preparations for DSAEK surgery, from June 2013 to August 2014, tissue thicknesses were divided into 3 groups, depending on surgeon preference: <91 μm (group A), 90 to 120 μm (group B), and 120 to 160 μm (group C). Precut and postcut data were recorded. Average postcut donor corneal thickness was 114 ± 30 μm (range 60-183 μm), whereas the average in group A was 97 ± 23 μm (range 60-128), in group B was 113 ± 21 μm (range 77-179), and in group C was 134 ± 43 (range 89-183). Average postcut endothelial cell density was very adequate at 3013 ± 250 cells per square millimeter. There were a total of 7 failed procedures from 256 attempts, which represents a rate of 2.7%. This rate decreases to 1.5% when analyzing the last 200 cuts. The ML7 Microkeratome Donor Cornea System allows for reliable and reproducible DSAEK tissue preparation. Ultrathin DSAEK tissues can be prepared with a single-pass. Aiming for a graft thickness between 90 and 120 μm seems to be most reliable.

Contact Lens-Assisted Pull-Through Technique for Delivery of Tri-Folded (Endothelium in) DMEK Grafts Minimizes Surgical Time and Cell Loss

To evaluate the feasibility and outcomes of contact lens-assisted bimanual pull-through delivery of Descemet membrane endothelial keratoplasty (DMEK) tissue trifolded with the endothelium inward. Prospective, noncomparative, interventional case series. Forty-two consecutive eyes of 42 patients with Fuchs endothelial dystrophy with or without cataract. Standardized DMEK was performed as a single procedure (n = 9) or in combination with phacoemulsification and implantation of a posterior chamber intraocular lens (n = 33) using prestripped donor tissue punched to a diameter of 8.25 mm and then trifolded with the endothelium in. Using a sterile soft contact lens as scaffold, the tissue was loaded in this configuration into a disposable cartridge and delivered into the anterior chamber under continuous irrigation using a bimanual pull-through technique to facilitate spontaneous proper unfolding. Surgical time, intraoperative and postoperative complications, visual acuity 3 and 6 months after surgery, and endothelial cell loss 6 months after surgery. Surgery was uneventful in all cases and the time required for the DMEK procedure (from Descemet scoring until final air filling) never exceeded 20 minutes (average, 17.1±1.6 minutes). The only complication observed after surgery was graft detachment (10 of 42 eyes [23.8%]), successfully managed in all cases by single rebubbling within 6 days from surgery. In all eyes with a minimum postoperative follow-up of 6 months (n = 20), best spectacle-corrected visual acuity was 20/25 or better and the average endothelial cell density (±standard deviation) was 2363.8±82.7 cells/mm(2) (range, 2258-2490 cells/mm(2)). The cell loss calculated as a percentage of the preoperative value determined at the eye bank (range, 2500-2700 cells/mm(2)) was 9.9±2.1% (range, 4.1%-11.9%). Delivering DMEK tissue, trifolded with the endothelium inward, reduces surgical trauma to donor cells and facilitates spontaneous unfolding, thus minimizing surgical time.

Preloaded donor corneal lenticules in a new validated 3D printed smart storage glide for Descemet stripping automated endothelial keratoplasty

PurposeTo design and validate the efficacy of three-dimensional (3D) printed smart storage glide (SSG) which is capable of preserving and delivering posterior lenticules for Descemet stripping automated endothelial keratoplasty (DSAEK).MethodsLaboratory...

Repeat Descemet Membrane Endothelial Keratoplasty after Complicated Primary Descemet Membrane Endothelial Keratoplasty

To describe the clinical outcome and complications of repeat Descemet membrane endothelial keratoplasty (re-DMEK). Retrospective case series study at a tertiary referral center. From a series of 550 consecutive DMEK surgeries with ≥ 6 months follow-up, 17 eyes underwent re-DMEK for graft detachment after initial DMEK (n = 14) and/or endothelial graft failure (n = 3). The outcomes were compared with an age-matched control group of uncomplicated primary DMEK surgeries. The re-DMEK eyes were evaluated for best-corrected visual acuity (BCVA), densitometry, endothelial cell density (ECD), pachymetry, and intraoperative and postoperative complications. Feasibility and clinical outcome of re-DMEK. In all eyes, re-DMEK was uneventful. At 12 months, 12 of 14 eyes (86%) achieved a BCVA of ≥ 20/40 (≥ 0.5); 8 of 14 eyes (57%) achieved ≥ 20/25 (≥ 0.8), 3 of 14 eyes (21%) achieved ≥ 20/20 (≥ 1.0), and 1 eye (7%) achieved 20/17 (1.2); 5 eyes were fitted with a contact lens. Average donor ECD decreased from 2580 ± 173 cells/mm(2) before to 1390 ± 466 cells/mm(2) at 6 months after surgery, and pachymetry from 703 ± 126 μm to 515 ± 39 μm, respectively. No difference in densitometry could be detected between re-DMEK and control eyes (P = 0.99). Complications after re-DMEK included primary graft failure (n = 1), secondary graft failure (n = 2), graft detachment requiring rebubbling (n = 1), secondary glaucoma (n = 2), cataract (n = 1), and corneal ulcer (n = 1). One eye received tertiary DMEK. In the management of persistent graft detachment and graft failure after primary DMEK, re-DMEK proved a feasible procedure. Acceptable BCVA may be achieved, albeit lower than after DMEK in virgin eyes, and some cases may benefit from contact lens fitting. Complications after re-DMEK may be better anticipated than after primary DMEK because graft detachment and graft failure tended to recur, suggesting that intrinsic properties of the host eye play a role in graft adherence and graft failure.

Risk factors for donor endothelial loss in eye bank-prepared posterior lamellar corneal tissue for descemet stripping automated endothelial keratoplasty.

The aim of this study was to investigate donor, tissue, and precut procedure risk factors for endothelial cell density (ECD) loss in posterior lamellar corneal tissue preparation by an eye bank for Descemet stripping automated endothelial keratoplasty. A total of 259 corneoscleral rims precut by the Singapore Eye Bank from October 2011 to August 2013 were evaluated. Donor characteristics, tissue characteristics, and precut procedure parameters were analyzed. The mean donor age was 57.18 ± 11.35 years, and the mean cutting transition time was 4.16 ± 0.75 seconds. The mean ECD was 2826 ± 225 and 2787 ± 224 cells per square millimeter before and after precutting, respectively, with an average ECD change of -1.38% ± 3.28%. The precutting procedure failure rate was 1.2%. Mutivariate regression analysis showed that an older donor age, a higher ECD before cutting, and a slower cutting transition speed were significant factors. Corneas with an ECD >2800 cells per square millimeter before precutting, cutting transition time >5.5 seconds, and corneas with donor age >65 years were significantly more likely to have greater than 5% ECD loss after precutting (odds ratio, 6.42, 1.66, and 1.62; 95% confidence interval, 1.44-29.43, 1.45-2.72, and 1.66-5.82, respectively). Donor source, death-to-preservation time (range, 0.67-10.88 hours), death-to-precutting time (range, 0-7 days), and graft thickness (range, 43-232 μm) were not statistically significant factors. The ECD loss in the precut tissue prepared by the eye bank was very low. The risk factors identified provide better understanding of how to improve the quality and safety profiles when preparing graft tissue for Descemet stripping automated endothelial keratoplasty.

Descemet's membrane preparation in eye banks for DMEK

AbstractEventhough Descemet Membrane Endothelial Keratoplasty (DMEK) results in unsurpassed improvement of postoperative visual acuity the complexity of graft preparation in DMEK prevents the wide spread use of this technique. Precut tissue preparation in eye banks for DMEK would make this technique amenable to a larger group of surgeons. Precut preparation of organ cultured corneas was preformed as previously described resulting in incompletely stripped Descemet’s membranes where a small central part was still attached to the corneal stroma. After subsequent culture for up to 5 days the precut grafts were used for DMEK. Visual acuity, central corneal thickness and endothelial cell density were retrospectively analyzed. Stripping was successfully completed in all grafts directly prior to surgery. The average visual acuity (logMAR) improved from 0.47 + 0.11 preoperatively to 0.2 + 0.13 3 months after DMEK. Central preoperative corneal thickness decreased from 632 + 46 µm preoperatively to 471 + 7 µm 3 months after DMEK. Average endothelial cell density was 2326 + 119 cells /mm2 before and 2226 + 150 cells/mm2 3 days after precut preparation (2 days before DMEK). 3 months after DMEK endothelial cell density further decreased to 1519 + 57 cells/mm2. Precut preparation of DMEK tissue, generated by incomplete Descemet stripping, leads to minor endothelial cell loss during subsequent culture and results in a fast visual recovery, only minor additional endothelial cell loss and a rapid decrease of corneal thickness.

Evaluation of grafted patients with donor corneas that today are more than 100 years old

Life expectancy is increasing. When corneal donors become older and corneal-grafted patients live longer with their graft, the need for good-quality donor tissue becomes more crucial. The aim of the present investigation is to study grafted recipients with a donor cornea with a total tissue age of more than 100 years. One thousand consecutive donor records from the Danish Cornea Bank were initially reviewed. After applying different inclusion criteria, 35 recipients with corneal donor tissue of more than 100 years of age were invited for a follow-up visit. Visual acuity, corneal transparency and thickness, and intraocular pressure were measured. Corneal topography and endothelial photos were taken. Seventeen of the invited patients attended the examination. The average age of the grafts at examination was 107 years old; the oldest being 118 years. Most grafts were still clear 23-35 years after transplantation, and almost one-fourth had best spectacle-corrected visual acuity (BSCVA) ≥ 0.50. Cell morphology showed irregularity in size and shape for both grafted and healthy corneas, but the alterations were more extensive in the grafted corneas. The average endothelial cell density (ECD) was 1360 mm(2) in the grafted corneas. Sixty per cent had ECD > 1000 cells/mm(2). No signs of decompensation were observed for those with <1000 cells. The average central corneal thickness of the grafts was 0.582 mm (SD = 0.067) compared with 0.494 mm (SD = 0.043) in the fellow cornea. This study shows a trend of moderate long-term survival and quality for very old grafts despite low ECD. Most recipients had a clear transplant, and one-fifth had BSCVA of 0.80.

Influence of the Precutting and Overseas Transportation of Corneal Grafts for Descemet Stripping Automated Endothelial Keratoplasty on Donor Endothelial Cell Loss

The authors evaluated the changes in donor endothelial cell density (ECD) caused by the precutting and long-distance transportation of corneal grafts for Descemet stripping automated endothelial keratoplasty (DSAEK) from overseas eye banks. A total of 124 consecutive precut donor tissues for DSAEK were obtained from overseas eye banks. The ECD was examined before precutting, after precutting, and after overseas transportation. Changes in ECD secondary to the precutting procedure and after long-distance transportation were evaluated. The average ECD before and after precutting was 2637 ± 336 and 2578 ± 305, respectively (P = 0.0063). The ECD after overseas transportation was 2468 ± 272, which is a significant decrease compared with the ECD after the precutting procedure (P < 0.001). The average rate of ECD loss was 1.75% for precutting and 3.79% for overseas transportation, with a total ECD loss of 5.68%. The ECD before surgery was >2000 cells per square millimeter in all cases, and all grafts were available for DSAEK. Imported precut donor corneas form overseas eye banks are a valuable source of donor corneas for DSAEK. The cell loss associated with precutting and the overseas transportation of corneal grafts on donor endothelial cell loss is acceptable.