Lions Eye Bank Research Articles

Microbiological screening of corneas stored in organ culture medium at Lions Eye Bank of Western Australia from 2011 to 2022.

The purpose of this study was to analyse the contamination rate of corneal samples stored in OCM at Lions Eye Bank of Western Australia over a 12-year period. All OCM samples used to preserve corneas from 2011 to 2022 (inclusive) underwent microbiological testing. Samples were collected into aerobic and anaerobic culture bottles on day 3-5 of corneal preservation and 24h after transfer to thinning medium. Samples were tested for 7days using the BACTEC FX system. Corneas remained in quarantine until clearance was obtained. From 2011 to 2022, 3009 corneas were retrieved and 2756 corneas were stored in OCM. Thirty one (1.1%) positive samples were reported, with 20 growths of bacterial origin and 11 fungal. Microbial contamination was mostly identified on day 1 of culture (77.5%). Donors of contaminated samples had a mean age of 55years, with 17 male and 14 female donors. The highest incidence of contamination came from donors whose cause of death was cancer. Death to enucleation times of contaminated samples ranged from 3.5 to 25.5h (mean = 13.5 ± 7.3) and death to preservation time ranged from 4.1 to 27.5h (mean = 14.8 ± 7.2). These did not significantly differ from the average time from death to enucleation (mean = 13.9 ± 3) and death to preservation (mean = 16.3 ± 4.2) of non-contaminated samples. Microbiological screening of corneas stored in OCM at LEBWA showed a very low rate of positive cultures with no predictive donor characteristics.

Performance outcomes from a DMEK peeling and preparation wet lab

ObjectiveTo evaluate the Descemet membrane endothelial keratoplasty (DMEK) preparation performance of trainee surgeons in an ex vivo human donor cornea DMEK wet lab simulation setting.MethodsHuman donor corneoscleral rims unsuitable for...

Comparison of corneal endothelial cell density and morphology with Optisol GS and Life4C storage media in the eye bank: a 5-year retrospective analysis.

Optisol GS and Life4C are corneal storage media used by eye banks worldwide. We sought to determine if either solution was associated with superior corneal endothelial cell density (ECD) or morphology in a large cohort of donor corneas. From January 2016 through December 2020, 10,316 corneas from 5,624 unique donors were acquired and analyzed at Rocky Mountain Lions Eye Bank. In April 2019, Life4C replaced Optisol GS as the sole storage medium. We compared ECD and morphology before and after April 2019, and excluded corneas processed within the transition period. Univariable and multivariable regression analyses accounted for age, sex, tobacco use, heavy alcohol use, and diabetes. Only right corneas were analyzed to account for the correlation between eyes. Of 5042 right corneas analyzed, 3486 were stored in Optisol GS and 1556 in Life4C. There was no significant difference in ECD across groups (2794 vs. 2793 cells/mm2 in Optisol GS and Life4C, p=0.88). In multivariate analyses, there was no significant difference in corneal ECD (0.6 cells/mm2 higher with Life4C, p=0.96) or hexagonality (0.22% higher with Life4C, p=0.31). However, the coefficient of variation was significantly lower in the Life4C group (-0.0039, p=0.03). After adjustment for above factors, corneas in Life4C demonstrated a 3.1% decreased likelihood of exhibiting CV values greater than 0.40 (p=0.009). This study demonstrates comparable and favorable outcomes using both storage media and confirms their overall efficacy. The decreased CV in Life4C is not of clinically significant magnitude, but merits further research in clinical and long-term settings.

Deformable Biomechanics of DMEK Tissue Scrolls Traveling Through Narrow Lumens: The Inverse Relationships Between Fluid Velocity, Scroll Width, and Wall Contact and Their Clinical Implications for Preloading.

The aim of this study was to evaluate Descemet membrane endothelial keratoplasty (DMEK) scroll width and length in relation to variable velocities as the tissue transits through wide and narrow lumen glass tubes. Sets of DMEK tissue were processed using the Iowa Lions Eye Bank standard DMEK protocol and were passed through 2 glass tube widths at variable speeds. Two hourglass-shaped glass tubes were created, one "wide" and one "narrow." A syringe pump, valve, and pressure gauge were used to modulate tissue speed through each tube. For both tube sizes, DMEK tissue was passed through their lumens with incrementally increasing velocity and visualized with a high-speed camera at frame rates from 1000 to 8000 fps. Scroll width and length were measured using IDT Motion Studio software and digital calipers. There was a significant, indirect correlation between scroll velocity and width in both the wide (R 2 = -0.98, P < 0.001) and narrow (R 2 = -0.84, P < 0.001) tubes. There was a significant, direct correlation between scroll velocity and length in both the wide (R 2 = 0.84, P < 0.001) and narrow (R 2 = 0.83, P < 0.001) tubes. The resting widths of the scrolls were 105% and 207% wider than the wide and narrow tubes, respectively. All transits recorded scroll widths that were equal to or smaller than their respective tube's internal diameter. There is a significant, inverse correlation between DMEK scroll velocity and width as well as a direct correlation between scroll velocity and length, allowing DMEK scrolls to transit through a tube that is narrower than its resting width without sustained lumen wall contact.

Using a Cone-Shaped Glass Funnel Adapter Reduces Endothelial Cell Loss Caused by Preloading Descemet Membrane Endothelial Keratoplasty Tissue.

The aims of this study were (1) to compare "front" and "rear" methods for loading Descemet membrane endothelial keratoplasty (DMEK) tissue into both micro-Jones and standard-Jones tubes and (2) to evaluate the efficacy of a cone-shaped glass funnel adapter designed to make loading DMEK tissue safer for corneal endothelial cells. The corneal endothelium was stained with 0.06% trypan blue to confirm equivalence between mate corneas. The tissues were then processed using the Iowa Lions Eye Bank standard DMEK protocol. In comparison 1, one mate was loaded into the rear of a micro-Jones or standard-Jones tube and the other was loaded into the front of the same tube. In comparison 2, one mate was loaded into the front of the micro-Jones tube and the other was loaded through the cone-shaped funnel adapter into the rear. All tissues were ejected through the front of the modified Jones tubes and assessed for endothelial cell loss (ECL) with calcein AM staining, FIJI, and Trainable Weka Segmentation; scroll widths were measured digitally. There were no statistically significant differences in ECL between front and rear loading [micro (N = 6 pairs): front 15.74% vs. rear 17.95%; standard (N = 6 pairs): front 19.58% vs. rear 19.17%; all P > 0.05]. DMEK scrolls loaded with the funnel adapter exhibited lower ECL compared with scrolls loaded through the front [micro (N = 8 pairs): front 13.53% vs. loading funnel 2.40%; P < 0.001]. Loading with the adapter was not faster (front 6.66 seconds vs. loading funnel 5.52 seconds; P = 0.24). Using a cone-shaped DMEK loading funnel may reduce ECL sustained during preloading.

The Lions Eye Bank of Western Australia: 35 Years of Eye Banking (1986–2021)

Purpose: The purpose of this study was to review the trends in preparation, storage, and usage of donor corneal tissue from 35 years of eye banking at the Lions Eye Bank of Western Australia (LEBWA). Methods: Donor and recipient records for the period July 1986 to July 2021 were evaluated with relation to donor demographics, cause of death, storage medium, corneal utilization, type of corneal graft, and indication for graft. Results: Six thousand two hundred nine eyes from 3328 donors were retrieved in the 35-year period reviewed. Sixty-six percent of eye donors were male, and 33% were female. The median age of donor was 61 years (2–98 years). The most frequent cause of donor death was a cardiac event, followed by intracerebral hemorrhage and malignancy. A total of 5219 corneal transplants were performed, with a corneal utilization rate of 84%. Storage of corneal tissue was primarily in Optisol-GS until 2010, when organ culture medium was introduced. Of 5219 recipients, 52% were male and 47% were female. The median recipient age was 63 years (1–98 years). Penetrating keratoplasty was the most common surgery performed over the 35-year period, followed by endothelial keratoplasty. The most common indications for grafts were ectasia/thinning, repeat corneal transplants, endothelial dystrophies, and postcataract surgery edema. Conclusions: We present trends in the acquisition and utilization of corneal tissue across 35 years at LEBWA. The most significant changes over this period include methods of corneal storage and advances in surgical techniques that has led to a greater usage of endothelial grafts.

Reply.

*Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH; and †University Hospitals Eye Institute, University Hospitals Cleveland Medical Center, Cleveland, OH. Supported by cooperative agreements with the National Eye Institute, National Institutes of Health, Department of Health and Human Services EY20797 and EY20798. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Eye Institute or the National Institutes of Health. Additional support provided by Eye Bank Association of America, The Cornea Society, Vision Share, Inc., Alabama Eye Bank, Cleveland Eye Bank Foundation, Eversight, Eye-Bank for Sight Restoration, Iowa Lions Eye Bank, Lions Eye Bank of Albany, San Diego Eye Bank, and SightLife. Analyses and manuscript preparation were supported by the JAEB Center Research Fund. Financial disclosures/conflicts of interest: J. H. Lass is a voluntary board member of Eversight and the Cleveland Eye Bank Foundation.

A histological study of atherosclerotic characteristics in age-related macular degeneration

This study investigated the pathogenesis of age-related macular degeneration (AMD) using histological methods that are commonly used for atherosclerotic vascular disease (ASVD). 1 normal, 3 early dry AMD, and 1 late dry AMD eyes were obtained from the Lions Eye Bank of Oregon and systematically dissected. They were stained with hematoxylin and eosin, Oil red O, Masson, Elastica van Gieson, Alizarin red, and Prussian blue. Additionally, the normal and late dry AMD eyes were immunostained for a-smooth muscle actin, CD45, and CD68 with Nile red and DAPI. Correlations were found between severity of AMD and lipid accumulation in the deep sclera (+), numbers of drusen between the Bruch's membrane and retinal pigment epithelium (RPE) (+), amount of collagen in the deep sclera (+), and amount of elastin in the deep sclera (-) (P < 0.1). Geographic atrophy, RPE detachment, and abnormal capillary shape and distribution in the choriocapillaris were observed in the fovea of late AMD. There were no stenosis, plaque, hemorrhage, and calcification. Additionally, late AMD tended to have higher smooth muscle thicknesses of the choroidal vascular walls, lower numbers of T lymphocytes in the choroid, and higher numbers of macrophages near the RPE and in the choroid relative to normal (P < 0.1). Macrophages-derived foam cells were detected near the Bruch's membrane in late AMD. Therefore, the present study showed many histological characteristics of ASVD in AMD, which suggests an association between them; however, there were also some histological characteristics of ASVD that were not found in AMD, which indicates that there exist pathogenic differences between them. The results generally support the vascular model of AMD, but some details still need clarification.

Approval rates for corneal donation and the origin of donor tissue for transplantation at a university-based tertiary referral center with corneal subspecialization hosting a LIONS Eye Bank

BackgroundWith the increasing demand for corneas, eye banks must optimize the tissue donation, collection, and selection process. This retrospective monocentric study analyzed the approval rates for corneal donation and the origin of and reasons for discarding donor corneas from 2010 to 2019.MethodsData included the number of deceased, approval or rejection by the family for corneal donation and contraindications. Corneal grafts were included from all deceased persons who were full-body and multi-organ donors at the Saarland University Medical Center (UKS) and from external institutions. Additional analyzed parameters included endothelial cell count (ECC), blood sample serology for infections, and conjunctival swab testing .ResultsA total of 1748 corneoscleral buttons were harvested from 10,265 deceased persons (17% with no contraindication) at the UKS between 2010 and 2019, with a consent rate of 23.3%. The number of explants increased from 136 in 2010 (15% of the deceased, total = 925) to 251 in 2019 (21%, total = 1214). Both the general and department-specific data showed similar percentages for corneal donation over the years, with intensive care and palliative units recently providing the most corneas. The increase in the number of corneas processed by the cornea bank over the years (368 in 2010 compared with 857 in 2019) was linked both to a better internal supply in 2010 (262, 71.2% of the total) compared with 2019 (519, 60.6%) and to an external supply by reinforcement of cooperation with external hospitals, including Luxembourg in 2010 (106, 28.8% of the total) compared with 2019 (338, 39.4%). A total of 195 of 377 corneas (52%) were discarded in 2009 compared with 260 out of 715 (36%) in 2019. The main reasons for discarding were low ECC (36% of discarded corneas in 2009; 11% in 2019), positive conjunctival swab (11% in 2009; 13% in 2019), and blood sample serology (6% in 2009 and in 2019).ConclusionDespite an increasing number of donors, the demand for corneas is still rising. Improved cooperation with internal departments and with external clinics has led to an increasing number of explanted corneas. The main reason for discarding corneas was low ECC, followed by a positive conjunctival swab for fungal or bacterial contamination and serology. Increased donation rates and continued improvements in collection and selection processes are necessary to cover the high demand for corneas.

No association between cataract surgery and mitochondrial DNA damage with age-related macular degeneration in human donor eyes.

To determine whether age-related macular degeneration (AMD) severity or the frequency of retinal pigment epithelium mitochondrial DNA lesions differ in human donor eyes that have undergone cataract surgery compared to phakic eyes. Eyes from human donors aged ≥ 55 years were obtained from the Minnesota Lions Eye Bank. Cataract surgery status was obtained from history provided to Eye Bank personnel by family members at the time of tissue procurement. Donor eyes were graded for AMD severity using the Minnesota Grading System. Quantitative PCR was performed on DNA isolated from macular punches of retinal pigment epithelium to quantitate the frequency of mitochondrial DNA lesions in the donor tissue. Univariable and multivariable analyses were performed to evaluate for associations between (1) cataract surgery and AMD severity and (2) cataract surgery and mitochondrial DNA lesion frequency. A total of 157 subjects qualified for study inclusion. Multivariable analysis with age, sex, smoking status, and cataract surgery status showed that only age was associated with AMD grade. Multivariable analysis with age, sex, smoking status, and cataract surgery status showed that none of these factors were associated with retinal pigment epithelium mitochondrial DNA lesion frequency. In this study of human donor eyes, neither retinal pigment epithelium mitochondrial DNA damage nor the stage of AMD severity are independently associated with cataract surgery after adjusting for other AMD risk factors. These new pathologic and molecular findings provide evidence against a relationship between cataract surgery and AMD progression and support the idea that cataract surgery is safe in the setting of AMD.

OCT Application for Sterile Corneal Graft Screening in the Eye Bank.

Sterile donor tomography enables the detection of corneal tissues with refractive anomalies. The aim of this study was to determine the curvature and thickness of donor corneas to support proper selection in the eye bank. 704 donor corneas (Klaus Faber Center, LIONS Eye Bank Saar-Lor-Lux, Trier/Westpfalz, in Homburg/Saar) were measured using the anterior segment optical coherence tomograph (AS-OCT) CASIA 2 (Tomey Corp., Nagoya, Japan). The corneoscleral discs were measured in their cell culture flask, which was positioned in a holder on the chin rest of the AS-OCT, after conversion to medium II (with 6% dextran T-500). The measured raw data were analysed and processed in MATLAB (MathWorks Inc., Natick, Massachusetts, USA), after which the refractive power of the steep and flat meridian at the anterior and posterior surface and the central corneal thickness (CCT) of the donor corneas were determined. Results values are expressed as mean x̅ ± standard deviation SD. The mean refractive power of the steep/flat meridian at the anterior surface was 45.4 ± 1.8 D/44.0 ± 1.3 D, the corresponding values for the posterior surface were - 6.2 ± 0.3 D/- 5.9 ± 0.2 D, and the mean CCT was 616.3 ± 85.1 µm. Of the 704 (100%) measured donor tissues, 590 (83.8%)/670 (95.2%) donor corneas showed no anomaly beyond respectively x̅ ± 2 SD/x̅ ± 3 SD among the 5 examined parameters. 72 (10.3%)/23 (3.3%) donor corneas had only 1 anomaly, 26(3.7%)/10 (1.4%) had 2 anomalies, 10(1.4%)/1 (0.1%), 3anomalies, 5 (0.7%)/0 (0.0%), 4 anomalies, and 1 (0.1%)/0(0.0%), 5 anomalies. AS-OCT provides an objective and sterile screening method to identify corneal tissues with curvature anomalies in order to further optimise donor selection in the eye bank. To avoid postoperative refractive surprises, donor corneas with a total refractive power that deviates > ± 3 SD from the mean should not be used for penetrating or anterior lamellar keratoplasty, but may be suitable for posterior lamellar keratoplasty (DMEK or DSAEK). In the future, sterile donor tomography could enable: (1) the harmonisation of donor and recipient tomography, which may minimise residual astigmatism for a particular donor-recipient pair; and (2) the improvement of IOL power calculation in a classical triple procedure by means of regression analysis between pre- and postoperative total refractive power of corneal grafts.

Viability of preloaded Descemet membrane endothelial keratoplasty grafts with 96-hour shipment

ObjectiveTo assess feasibility and compare the effects of 96-hour shipment of Descemet membrane endothelial keratoplasty (DMEK) grafts as a scroll or a tri-fold on cell viability.Methods and analysisDMEK grafts were...

How Implementing a Quality Management System at the LIONS Eye Bank Saar-Lor-Lux, Trier/Western Palatinate from 2006 to 2016 Impacted the Rate and Reasons for Discarding Human Organ-Cultured Corneas

The aim of this study was to explore how the implementation of the quality management system (QM; according to DIN EN ISO 9001 : 2008) at the LIONS Eye Bank impacted the rate and reasons for discarding donated corneas. The QM system was introduced in November 2010. The rate of and reasons for discarding cornea tissues at the LIONS Eye Bank Saar-Lor-Lux,Trier/Western Palatinate from 2006 to 2016 were analysed retrospectively. 4,140 corneas from 2,084 donors were analysed. 1,640 corneas were processed before the QM system had been introduced and 2,500 corneas thereafter. Main reasons for discarding cornea tissues were endothelial quality, contamination of the medium and a positive conjunctival swab. The data was extracted from clinical files and data filing systems, entered into a Microsoft Access database and analysed statistically with SPSS. Following the implementation of a QM system, the discard rate decreased significantly from 50.1% to 39.7% (p < 0.0001). Prior to the implementation of the QM system, 493 (30.1%) cornea tissues had been discarded due to endothelial quality, while this figure improved significantly to 604 (24.2%) after the QM system had been implemented (p < 0.0001). Contamination was the reason for discarding tissue in 173 (10.5%) cases before implementation of the QM system, and in 124 (5.0%) cases thereafter (p < 0.0001). Positive conjunctival swab was the reason for discarding tissue in 10 (0.6%) cases before the QM system had been implemented, and in 53 (2.1%) cases thereafter (p < 0.0001). Implementation of a QM system significantly reduced the rate of discarded donor tissue in the LIONS Eye Bank. Better management of contamination as a reason for discarding cornea tissues can be attributed to improved standards, protocols and training that are part of this QM system.

A Histological Study of Atherosclerotic Characteristics in Age-Related Macular Degeneration

This study investigated the pathogenesis of age-related macular degeneration (AMD) using histological methods that are commonly used for atherosclerotic vascular disease (ASVD). 1 normal, 3 early dry AMD, and 1 late dry AMD eyes were obtained from the Lions Eye Bank of Oregon and systematically dissected. They were stained with hematoxylin and eosin, Oil red O, Masson, Elastica van Gieson, Alizarin red, and Prussian blue. Additionally, the normal and late dry AMD eyes were immunostained for a-smooth muscle actin, CD45, and CD68 with Nile red and DAPI. Correlations were found between progression of AMD and lipid accumulation in the deep sclera (+), numbers of drusen between the Bruch’s membrane and retinal pigment epithelium (RPE) (+), amount of collagen in the deep sclera (+), and amount of elastin in the deep sclera (-) (P < 0.1). Geographic atrophy, RPE detachment, abnormal choriocapillaris structure, and decreased choriocapillaris density were observed in the fovea of late AMD. There were no stenosis, plaque, hemorrhage, and calcification. Additionally, late AMD tended to have higher smooth muscle thicknesses of the choroidal vascular walls, lower numbers of T lymphocytes in the choroid, and higher numbers of macrophages near the RPE and in the choroid relative to normal (P < 0.1). Macrophages-derived foam cells were detected near the Bruch’s membrane in late AMD. The results show many histological characteristics of ASVD in AMD, which suggests an association between them. They generally support the vascular model of AMD, but some details still need clarification. Funding: This work is supported by the Beijing Natural Science Foundation (project no. 7154215) and the National Natural Science Foundation of China (project no. 81771347). Declaration of Interests: None to declare. Ethics Approval Statement: The study was approved by the Biological Science and Medical Engineering Ethics Committee of the Beihang University. The identification number this committee gave to my approved research is: BM201900085

In-vitro and ex-situ regional mass spectral analysis of phospholipids and glucose in the vitreous humor from diabetic and non-diabetic human donors

The causes of vitreous humor (VH) liquefaction remain unclear. Diabetes accelerates this process and other ocular diseases. The weakening of the blood-retina barrier observed with diabetes could enhance the rate of transfer of relatively small molecules such as glucose (Glu) and phospholipids (PLs) from the retina to the VH. Glucose and PLs have been detected previously in VH but their regional distributions are not known. The mapping of Glu and PLs in VHs from subjects with and without diabetes could reveal the roles of these molecules in VH liquefaction. Diabetic and non-diabetic human eyes were acquired from the Kentucky Lions Eye Bank and frozen immediately. Each VH was removed and halved along the sagittal plane. One half was stamped on a matrix assisted laser desorption ionization (MALDI) plate. Either p-Nitroanaline (26 mg/mL MeOH:CHCl3) or 2,5-dihydroxybenzoic acid (20 mg/mL H2O:acetonitrile) was used as matrix. Glu and PLs were extracted from the remaining sections and analyzed. Data were acquired using a MALDI-mass spectrometer. The levels of Glu and PLs were significantly greater in VH from diabetics (VHd) compared with VH from non-diabetics (VHnd). VHds showed the highest relative levels of PLs in the posterior VH, followed by the anterior and central regions. Throughout the entire VH, the most abundant PLs were phosphatidylcholines followed by sphingomyelins. For Glu, the relative intensities were ~3 times higher in the posterior region of VHd (12 ± 1.3) compared with VHnd (6.5 ± 0.7) VHs. Regional studies showed that relative to the posterior VHd, the Glu levels were lower in the anterior (8.1 ± 1.0) and central (6.7 ± 0.8) regions. For the VHnds, the values for the central and anterior regions were 5.9 ± 1.2 and 4.7 ± 0.9, respectively. PLs and Glu are most abundant in the posterior region relative to the central and anterior zones of VHs. This trend was observed in VHd and VHnd, but PLs and Glu levels were significantly higher in VHds. These results support the possibility that higher levels of Glu and PLs accelerate VH liquefaction in diabetic patients. As liquefaction begins in the posterior region, the higher abundance of PLs and Glu in this zone also suggests that they may play a role in liquefaction. The specific molecular interactions affected by Glu and PLs in the collagen/hyaluronan/water network need to be examined.

Cooperation between the department of ophthalmology at the University of Düsseldorf (Germany) and the Fundación Visión in Asunción (Paraguay) as an example of the German hospital partnerships programm

HintergrundSeit 2014 besteht auf der Basis eines Memorandum of Understanding eine Partnerschaft zwischen der Universitätsaugenklinik Düsseldorf (UAK Düsseldorf) und der Fundación Visión (FV) in Asunción, die eine führende Rolle in der augenärztlichen Behandlung sowie der Prävention von Erblindung in Paraguay einnimmt. Seit 2016 existiert ein Programm zur Förderung internationaler Klinikpartnerschaften der Bundesregierung.Material und MethodenDie Klinikpartnerschaft Düsseldorf–Asunción wird nach schriftlichem Antrag im Jahr 2016 durch das Ministerium für wirtschaftliche Zusammenarbeit gefördert. Im Rahmen der Projektlaufzeit sollen mithilfe mehrerer Aktivitäten in einem definierten Zeitplan moderne, minimal-invasive Hornhauttransplantationstechniken, die eine schnellere postoperative Rehabilitation und weniger Nachsorge erfordern, in Paraguay etabliert werden. Zusätzlich sollen erste Prävalenzdaten von Augenerkrankungen erhoben und die Basis für moderne Hornhautbanktechniken geschaffen werden.ErgebnisseZunächst erfolgte die Ausbildung eines paraguayischen Operateurs in der Durchführung von DMEK-Transplantationen in Deutschland. Zeitgleich wurden die instrumentellen Voraussetzungen für die Etablierung der DMEK-Technik in der FV geschaffen. Im September 2018 wurden unter Supervision eines erfahrenen OP-Teams aus Düsseldorf die ersten lamellären Hornhauttransplantationen durch das Team der FV erfolgreich in Paraguay durchgeführt. In der Folge wurden in Asunción auch die Verwendung einer Spenderhornhaut für je ein Transplantat für eine hintere und eine vordere lamelläre Keratoplastik (DMEK und DALK) umgesetzt. Im November 2019 erfolgte eine epidemiologische Datenerhebung zu Augenerkrankungen im Rahmen einer Feldkampagne der Fundación in einer ländlichen Region Paraguays. In deren Zug erlernte der datenerhebende Mitarbeiter der Universitätsaugenklinik Düsseldorf die Technik der manuellen Kleinschnittkataraktchirurgie. Im März 2019 wurde ein Mitarbeiter der FV in Düsseldorf in den Techniken der Hornhautgewebekultur und der Herstellung von Amnionmembrantransplantaten in der Lions-Hornhautbank NRW geschult.SchlussfolgerungMithilfe einer geförderten Klinikpartnerschaft können moderne minimal-invasive Hornhauttransplantationstechnik erfolgreich in die Augenklinik eines Schwellenlandes transferiert und im Gegenzug chirurgische Fertigkeiten für in Ausbildung befindliche Operateure aus Deutschland vermittelt werden. Damit stellt eine effiziente Klinikpartnerschaft die Grundlage für einen wechselseitigen Austausch dar und ist keine reine Einbahnstraße.

Corneae from body donors in anatomy department: valuable use for clinical transplantation and experimental research

BackgroundExplanted corneae are highly needed for the surgical management of patients with severe corneal diseases. The aim of this study was to determine whether the body donors from the Institute of Anatomy are a suitable source of donor corneae.MethodsAt the Institute of Anatomy at Saarland University Medical Center in Homburg, corneae are prelevated from body donors who had consented to the removal of tissues for transplantation purposes during their lifetime. Following the report of death, the LIONS Eye Bank is informed and the contraindications of corneal explantation are clarified. Obtaining a blood sample within 24 h postmortem is mandatory.ResultsThe Institute of Anatomy had 150 body donors in the time period from January 2018 to June 2019. Out of these, 68 (45.3%) were reported to the Eye Bank. The age of the donors (median 82 years (range: 57–96)) is not critical since the quality of the corneae depends on the number of endothelial cells (mean: 2109 ± 67 cells/mm2 (range: 511–2944 cells/mm2)). Contraindications were present in 19 (12.6%) cases. The corneae were extracted from 49 (32.7%) body donors. Out of these 98 corneae, 46 (46.9%) were successfully transplanted. Of all non-transplanted corneae, 6 (6.1%) were microbiologically contaminated, 10 (10.2%) had a positive serology, 22 (22.5%) had an endothelial cell count < 2000 cells/mm2 and 6 (6.1%) are at time of this analysis still in culture medium. The non-transplanted tissues were used for research.ConclusionsExplanted corneae from the Institute of Anatomy are a valuable option in obtaining grafts for corneal transplantation, which is why we are working toward on expanding cooperation with this department.

Ex-vivo cultured human corneoscleral segment model to study the effects of glaucoma factors on trabecular meshwork.

Glaucoma is the second leading cause of irreversible blindness worldwide. Primary open angle glaucoma (POAG), the most common form of glaucoma, is often associated with elevation of intraocular pressure (IOP) due to the dysfunction of trabecular meshwork (TM) tissues. Currently, an ex vivo human anterior segment perfusion cultured system is widely used to study the effects of glaucoma factors and disease modifying drugs on physiological parameters like aqueous humor (AH) dynamics and IOP homeostasis. This system requires the use of freshly enucleated intact human eyes, which are sparsely available at very high cost. In this study, we explored the feasibility of using human donor corneoscleral segments for modeling morphological and biochemical changes associated with POAG. Among the number of corneas donated each year, many are deemed ineligible for transplantation due to stringent acceptance criteria. These ineligible corneoscleral segments were obtained from the Lions Eye Bank, Tampa, Florida. Each human donor anterior corneoscleral segment was dissected into four equal quadrants and cultured for 7 days by treating with the glaucoma factors dexamethasone (Dex) or recombinant transforming growth factor (TGF) β2 or transduced with lentiviral expression vectors containing wild type (WT) and mutant myocilin. Hematoxylin and Eosin (H&E) staining analysis revealed that the TM structural integrity is maintained after 7 days in culture. Increased TUNEL positive TM cells were observed in corneoscleral quadrants treated with glaucoma factors compared to their respective controls. However, these TUNEL positive cells were mainly confined to the scleral region adjacent to the TM. Treatment of corneoscleral quadrants with Dex or TGFβ2 resulted in glaucomatous changes at the TM, which included increased extracellular matrix (ECM) proteins and induction of endoplasmic reticulum (ER) stress. Western blot analysis of the conditioned medium showed an increase in ECM (fibronectin and collagen IV) levels in Dex- or TGFβ2-treated samples compared to control. Lentiviral transduction of quadrants resulted in expression of WT and mutant myocilin in TM tissues. Western blot analysis of conditioned medium revealed decreased secretion of mutant myocilin compared to WT myocilin. Moreover, increased ECM deposition and ER stress induction was observed in the TM of mutant myocilin transduced quadrants. Our findings suggest that the ex-vivo cultured human corneoscleral segment model is cost-effective and can be used as a pre-screening tool to study the effects of glaucoma factors and anti-glaucoma therapeutics on the TM.

Determining the Willingness of Australians to Export Their Corneas on Death

Background: 12.7 million people await a corneal transplant, but 53% are without access to corneal tissue. Sharing corneal tissue across nations can provide some access, however the willingness of export populations, like Australians, to export their donation on death, has never been evaluated. Our research samples the Australian population, determining their willingness to export. Method: We conducted e-surveys. N=1044 Australians participated. The sample represented the Australian population, based on population demographics. Chi-Square and bivariate correlation coefficients examined associations between continuous variables, with a sample size of N=1044, power of 0.80, and alpha of p = 0.05. Outcome measures were based on population sampling, by exploring willingness export, through the e-survey method. Findings: 38% (n=397) of respondents said yes to exportation, 23.8% (n=248) said no, and 38.2% (n=399) were undecided. We found no relationship between willingness to export and general demographics, though those registered on the Donatelife Register (p= < .001), and those already willing to donate their eyes (p= < .001) were significantly more willing to export. Interpretation: More Australians are willing to export their corneas than not, though a significant portion remain undecided. The Donatelife Register and donation awareness are key components of respondent decision making. Therefore, provision of information about exportation prior to, and at the point-of-donation, is essential for assisting Australian’s to decide to export or not. Further examination and development of consent-for-export systems are necessary before routine exportation is undertaken. Funding: National Health and Medical Research Council; Lions Eye Bank of Western Australia. Declaration of Interests: Authors have no competing or conflicting interest. Ethics Approval Statement: Approval for this study was obtained from the Royal Victorian Eye and Ear Hospital’s Human Research Ethics Committee (HREC#18-1374H).

Automated Cell Counting Using "Deep Learning" in Donor Corneas from Organ Culture Achieves High Precision and Accuracy

Human corneal grafts from organ culture need to have more than 2000 endothelial cells/mm2 to be suitable for transplantation. Measurement of the endothelial cell density is complicated by invisible cell borders in phase contrast microscopy, as well as by limited areas for counting due to folds in the Descemet membrane of the swollen corneal grafts. To date, no automated counting method for measuring the endothelial cell density exists. The neuronal network U-Net has already proven itself in automated segmentation of specular microscopy images of human corneal endothelium. The aim of this study was the application of the U-Net in the quality control of human corneal grafts. Training of the U-Net was performed using 100 manually tagged endothelial cell images of corneal grafts from the Lions eye bank in Baden-Württemberg. Another 100 images were obtained for testing the precision of measurements of the U-Net. These were adjudged manually by a) an experienced investigator and b) a less experienced ophthalmologist. The endothelial cells in identical images were then counted automatically by the trained U-Net. Comparison with the manually counted results was drawn by Pearson correlation. The correlation coefficient between the U-Net and the experienced investigator as gold standard was 0.9. The correlation coefficient between the less experienced ophthalmologist and the gold standard was only 0.81. Both correlations were statistically highly significant (p < 0.0001). The strong correlation between the U-Net and the gold standard points out that, given medical approval, effective assistance for eye banks is possible in quality control by automated counting. This could improve objectivity and efficiency of work flow.