National Consensus on Contraindications for Corneal Donation for Transplantation in Switzerland.

PURPOSE: To establish a national consensus on contraindications for corneal donation for transplantation in Switzerland. METHODS: Swisstransplant (SWT), the Swiss national foundation coordinating tissue and organ donations, convened a working group consisting of six national corneal surgeons and eye bankers and donation experts to create a contraindication list for corneal donation. The group reviewed available national and international guidelines and recommendations, while adhering to Swiss law and transplant regulations. In cases of opposing opinions, the group held follow-up meetings until a consensus was reached. A consensus was defined as agreement among all parties present. RESULTS: From March 2021 to November 2021, the study group held six meetings and created a standardized minimal contraindication list for corneal donation in Switzerland. Thanks to this list, SWT has created a mandatory working and documentation file for donor coordinators to use when evaluating multiorgan donors for corneal harvesting. The authors agreed that while the national consensus list provides standardized minimal contraindication criteria, local eye banks may choose to introduce additional, more rigorous criteria. CONCLUSION: Given that corneal transplantation is the most commonly performed transplantation, establishing a consensus on contraindications is crucial for recipient safety. The creation of a consensus on contraindications for corneal donation in Switzerland is an essential contribution to fulfil the legal requirements concerning quality assurance and provides sufficient high-quality donor tissue within the country. Therefore, periodic review and revision of the consensus is considered critical.

Quality assurance in corneal transplants: Donor cornea assessment and oversight.

The cornea is the most frequently transplanted human tissue, and corneal transplantation represents the most successful allogeneic transplant worldwide. In order to obtain good surgical outcome and visual rehabilitation and to ensure the safety of the recipient, accurate screening of donors and donor tissues is necessary throughout the process. This mitigates the risks of transmission to the recipient, including infectious diseases and environmental contaminants, and ensures high optical and functional quality of the tissues. The process can be divided into 3 stages: (1) donor evaluation and selection before tissue harvest performed by the retrieval team, (2) tissue analysis during the storage phase conducted by the eye bank technicians after the retrieval, and, (3) tissue quality checks undertaken by the surgeons in the operating room before transplantation. Although process improvements over the years have greatly enhanced safety, quality, and outcome of the corneal transplants, a lack of standardization between centers during certain phases of the process still remains, and may impact on the quality and number of transplanted corneas. Here we detail the donor screening process for the retrieval teams, eye bank operators. and ophthalmic surgeons and examine the limitations associated with each of these stages.

Performance outcomes from a DMEK peeling and preparation wet lab.

OBJECTIVE: To evaluate the Descemet membrane endothelial keratoplasty (DMEK) preparation performance of trainee surgeons in an ex vivo human donor cornea DMEK wet lab simulation setting. METHODS: Human donor corneoscleral rims unsuitable for transplantation were obtained from Moorfields Lions Eye Bank. At the wet lab, graft stripping was performed by scoring the peripheral endothelium. The trypan blue positive cells (TBPC) and cell density (cells/mm2-reticule count) were counted manually before and after stripping. The procedural time, peripheral and central tears and complete peel-off were also recorded and analysed. RESULTS: Eight trainee surgeons attended the wet lab each attempting three DMEKs. Between the first and last attempts a significant decrease was seen in the procedural time (17.6 min vs 10.6 min (p<0.05)) and the TBPC % (12.9% vs 3.8% (p<0.05)). The percentage of tears peripherally and centrally also reduced between the first and the last trials (50% vs 13% (p=0.2226) and 38% vs 0% (p=0.1327)). A significant correlation was found between longer peeling times and higher TBPC % (p<0.001) with a 0.7% endothelial mortality increase for each additional minute required to complete the peel. CONCLUSIONS: DMEK wet labs provide a controlled risk-free learning opportunity for trainee surgeons to improve confidence and competence. Wet labs improve the success rate of DMEK graft preparation as well as flatten the learning curve. This emphasises the importance of continued support for the expansion of this valuable learning resource, promoting wider uptake of DMEK surgery.

[Attach importance to the orderly development of different corneal transplant procedures].

There are various surgical methods for corneal transplantation, each requiring precise treatment tailored to the characteristics and different layers of corneal opacity or lesions. These layers include the corneal epithelium, stroma (lamellar), and corneal endothelium, with options for full-thickness (penetrating) corneal transplantation or artificial corneal transplantation. However, a current issue in clinical practice is that, regardless of the degree of corneal disease, the availability of corresponding eye bank support, or surgical conditions, classic penetrating (full-thickness) corneal transplantation is universally performed. Alternatively, there is a trend toward adopting technically demanding procedures such as endothelial transplantation and artificial corneal transplantation. This trend has led to increased postoperative complications and the wastage of corneal donor materials. Choosing the appropriate corneal transplant procedure can offer advantages such as preserving more healthy corneal tissue, conserving corneal donors, facilitating rapid vision recovery, and minimizing the risk of immune rejection. Corneologists need to master the indications for various corneal transplant surgeries and systematically perform different corneal transplant procedures based on the surgeon's skills, hospital conditions, and eye bank conditions. This approach aims to enhance the success rate of the surgery.

Corneal endothelial validation in the eye bank: differences in automated methods and repeatability.

PURPOSE: To evaluate reproducibility of endothelial cell density (ECD) measurements using the Konan Cell Check D in donor corneas by two different ophthalmologists and to compare the two automated cell count methods (center and flex-center) available in the software of this specular microscope. METHODS: ECD values were quantified in 54 donor corneas by two independent investigators using the Cell Check D (Konan Medical USA Inc) with both automated cell count methods. In the center method, at least 30 contiguous cells are marked. For the flex-center method, an area is delineated and only the cells within the designated area are counted. RESULTS: The mean ECD was 2473.81±378.22 cells/mm2. Good ECD intergrader reproducibility for the center (ICC=0.821) and the flex-center method (ICC=0.784) were noted. Poor reliability was observed for coefficient of variation and hexagonality (ICC≤0.265). When both methods for ECD analysis were compared, a moderate correlation for the two independent graders using the two manual (center and flex-center) methods was detected (correlation coefficient of 0.678 and 0.745 for each of the investigators). Comparison between methods yielded significantly higher ECD with the flex-center method (P=0.013). When corneas were divided by ECD, those under 2200 cells/mm2 and those between 2200 and 2700 cells/mm2 also had significantly higher ECD with the flex-center method (P<0.022). CONCLUSIONS: ECD values are reproducible with both methods, although the flex-center method ECDs tend to be higher, particularly in cases of low ECD. Eye banks and surgeons should exercise caution in making decisions based only on small differences in ECD.

Trends in keratoplasty from central and northern India. Part II: Types of keratoplasty.

PURPOSE: To report the types of keratoplasty and analyze trends over a period of two decades in central and northern India. METHODS: This was a retrospective review of eye bank registries of six tertiary eye care centers located in central and north India from 2005 to 2021. The indications and various keratoplasty procedures were compared between 2005-2012 and 2013-2021 to analyze the trend. RESULTS: A total of 13,223 corneal grafts were performed, of which therapeutic penetrating keratoplasty (TPK) (5719, 43.3%) was the most common procedure, followed by optical penetrating keratoplasty (OPK) (5528, 41.8%), Descemet stripping endothelial keratoplasty (DSEK) (1279, 9.7%), deep anterior lamellar keratoplasty (DALK) (376, 2.8%), Descemet membrane endothelial keratoplasty (DMEK) (215, 1.6%), patch grafts (75, 0.6%), and keratoprostheses (31, 0.2%). Overall, OPK procedures decreased (-14.1%, P < 0.001), but TPK (+3.1%, P < 0.019), DSEK (+7.1%, P < 0.001), and DMEK (+1.9%, P < 0.001) procedures increased. Although there was an increasing trend in the use of DALK (+0.8%, P < 0.083) and keratoprostheses (+0.3%, P = 0.074) procedures, the trends were not statistically significant. CONCLUSION: In keeping with worldwide trends, an increasing trend in lamellar keratoplasties was observed in central and northern India during the past decade. The trend was significant for DSEK. However, as corneal ulcers and scars were the major indications for keratoplasty, TPK and OPK remained the most common procedures.

Characterization of cornea donors at a tissue center in the city of Medellin, Colombia.

The cornea transplant is considered the most frequently performed type of transplant in the world, with a demand that has been increasing in recent years. An observational descriptive study was conducted, focusing on the ocular tissue extracted from cadaveric donors from January 2019 to December 2021 at the Red Cross Eye Bank in Medellin, Colombia. This is the first epidemiological characterization of corneal donor tissues within the eye banks of our city, where high rates of violence-related deaths explain that tissue donors are mostly young individuals. This, in turn, results in excellent counts of endothelial cells and tissue viability in their microscopic studies. Additionally, there are lower rates of discarded tissues compared to similar studies.

Principais motivos de descarte de córneas para transplante na Paraíba: por que o anti-HBc merece atenção?* / Main reasons for discarding corneas for transplant in Paraíba: why does anti-HBc deserve attention?*

RESUMO Objetivo: Identificar o perfil dos doadores de tecidos oculares humanos na área de atuação do Banco de Olhos da Paraíba, destacando o impacto da sorologia positiva para hepatite B no descarte dos tecidos para transplante. Métodos: O estudo é transversal e utilizou dados do Banco de Olhos da Paraíba entre janeiro de 2013 e dezembro de 2022. Dados sobre procedência, idade, sexo, causa do óbito, tempo entre óbito e enucleação, resultados sorológicos e motivo de descarte das córneas dos doadores foram coletados. Resultados: O maior motivo de descarte foi por sorologia positiva (56,5%), sendo positivadas as sorologias positivas para hepatite B e HBsAg em 11,1% e 4,75% dos pacientes, respectivamente. Conclusão: A sorologia positiva para hepatite B como um critério de descarte absoluto é responsável por grande parcela de descartes, apesar da pouca informação sobre suas repercussões e representação de infectividade nos receptores do transplante.

ABSTRACT Objective: To identify the profile of human ocular tissue donors in the area covered by the Eye Bank of Paraíba (PB), highlighting the impact of positive serology for hepatitis B (anti-HBc) in the disposal of tissues for transplantation. Methods: This is a cross-sectional that uses data from the Eye Bank of Paraíba (PB) between January 2013 and December 2022. Data on origin, age, sex, cause of death, time between death and enucleation, serological results, and reason for discarded donor corneas were collected. Results: The main reason for discarding was due to positive serology (56.5%), with positive anti-HBc and HBsAg serology in 11.1% and 4.75% of patients, respectively. Conclusion: Anti-HBc positive serology as an absolute disposal criterion is responsible for great part of disposals, despite little information about its repercussions and representation of infectivity in transplant recipients.

[Analysis of factors affecting the quality of donor corneal endothelial cells].

Objective: To explore the factors influencing the quality of donor corneal endothelium. Methods: A retrospective case series study was conducted. Data from 568 donor corneas obtained from the Shandong Eye Bank between July 1, 2020, and June 30, 2021, were collected for analysis. The corneal endothelium of the donor corneas was observed using corneal endothelial microscopy to assess corneal endothelial cell density (ECD), coefficient of variation, and hexagonal cell ratio (HEX). Relevant factors of corneal donors were collected, including gender, age, cause of death, season of death, time from death to corneal retrieval, and methods of corpse preservation, to investigate their impact on the quality of donor corneal endothelium. The age factor was divided into five age groups: 0-20 years, 21-40 years, 41-60 years, 61-80 years, and >80 years. The time of corneal retrieval was divided into three periods based on the time elapsed since the donor's death: <6 hours, 6-12 hours, and >12 hours. The relationship between these factors and corneal endothelial conditions was analyzed. Results: The 568 donor corneas were obtained from 288 donors, including 225 males (78.13%) and 63 females (21.87%). The mean age was 51.77±18.48 years. The causes of death among donors were as follows: cardiovascular diseases 54.58% (275 individuals), cancer 17.96% (74 individuals), organ failure 14.26% (49 individuals), and accidents 13.20% (64 individuals). The mean time of corneal retrieval after donor death was 140 (76, 400) minutes (ranging from 30 minutes to 45 hours). Among the 145 corneas (25.53%) that had their initial corneal endothelial microscopy examination, the images were not clear, and after thorough rewarming, 106 corneas (18.7%) still had unclear images and could not be analyzed. Among the 462 corneas (81.3%) with clear images, the ECD was (2 602.23±318.40) cells/mm², the coefficient of variation was 36.61%±4.81%, and the HEX was 52.73%±7.15%. The ECD of corneas from older donors was lower compared to younger donors, and the differences between age groups were statistically significant (P<0.001). Corneas from donors who died due to accidents had a higher ECD [(2 829.88±313.90) cells/mm²] compared to those who died from cancer, cardiovascular diseases, and organ failure, and the differences were statistically significant (P<0.001). The ECD was highest when corneas were retrieved within 6 hours after death, and the difference was statistically significant (P<0.001). Older donors had higher coefficients of variation but lower HEX values (both P<0.05). Corneas retrieved after a longer time from death had higher coefficients of variation, and the difference was statistically significant (P<0.05), but there was no statistically significant difference in HEX (P>0.05). Organ failure, cryopreservation, and corneal retrieval time >12 hours were risk factors for unclear corneal endothelial imaging (all P<0.001). Among the 136 corneal endothelial images (23.94%), circular, oval, or band-shaped dark areas were observed, and corneas with dark areas had lower ECD (P<0.05). The longer the time elapsed from death to corneal retrieval, the more dark areas were observed (P<0.001). The presence of dark areas did not affect the coefficient of variation and HEX (P>0.05). Conclusion: Advanced donor age, death due to chronic diseases, longer time elapsed from death to corneal retrieval, and cryopreservation of the body lead to a decrease in the quality of donor corneal endothelium.

P23-A137†Cross-border cooperation for corneal donation between lions eye bank Saar-Lor-Lux, Trier/Westpfalz in Homburg/Saar and Luxembourg.

PURPOSE: With the increasing demand for corneas, eye banks must optimize and extend their sources of tissue donation. On the other hand, corneal transplantation is a specialized procedure performed in hospitals with high quality standards and ideally an integrated eye bank. In this report we would like to focus on an international win-win-win agreement between the Department of Ophthalmology at Saarland University Medical Center (Homburg/Saar, Germany), the LIONS Eye Bank Saar-Lor-Lux, Trier/Westpfalz and the four major non-university hospitals without corneal transplantation competence in Luxembourg. METHODS: In 2012, at the initiative of the Luxembourgish Ministry of Health and Department of Ophthalmology (Homburg/Saar, Germany), an international agreement was established with the Centre Hospitalier du Luxembourg (Luxembourg). Administrative and legislative rules were developed. Luxembourgish nursing personnel attended a practical training program for corneal excision at the Department of Ophthalmology in Homburg/Saar allowing them to harvest the two first corneal donors on site by themselves during the first year. In the following years two more hospitals, the Centre Hospitalier Emile Mayrisch (Esch-sur-Alzette, Luxembourg) and the Hôpitaux Robert Schuman (Kirchberg, Luxembourg), joined the cooperation. RESULTS: From 2012 until 2021, three hospitals in Luxembourg donated 779 corneas to the LIONS Eye Bank of the Saarland University Medical Center in Homburg/Saar (Germany). In return, 308 Luxembourgish patients have received a corneal transplantation at the Department of Ophthalmology in Homburg/Saar. In 2022, the extension continued and an agreement with a fourth hospital in Luxembourg at the Centre Hospitalier du Nord (Ettelbruck, Luxembourg) was signed providing even more donations. CONCLUSION: The cross-border collaboration for corneal donation and patient treatment has proven to be successful with both numbers of harvested donors and transplanted patients rising. However, international legislation for tissue donation needs to be accurately respected and a quality management system established to provide continuous quality of the donor tissue.

P28-A146†The impact of COVID-19 pandemic on eye banking in the Lublin Eye Bank, Poland.

PURPOSE: The purpose of this study was to investigate the impact of the COVID-19 pandemic on the Lublin Eye Bank activities. METHODS: We compared the corneal donors screening rules, number of harvested corneas before, during, and after the pandemic (2019, 2020, 2021, 2022 years). RESULTS: In 2019 we had 182 corneal donors and 360 harvested corneas; in 2020 - 114 donors and 227 corneas; in 2021 - 151 donors and 300 corneas, and in 2022 till the 15th November - 115 donors and 228 corneas. From the 11th March 2020, when the World Health Organization had declared a global pandemic, our Eye Bank ceased all activities until the 10th May 2020. We started then, according to recommendations of Polish Transplantation Society, performing a nasopharyngeal swabs specimen collecting for every corneal donor. In 2020 we noted only 1 positive donor, whereas in 2021 we had 9 and in 2022 - 12 SARS-CoV-2 positive donors, respectively. Overall mean reduction in the number of corneal donors and obtained corneal tissues of 6,3% was observed in the Lublin Eye Bank CONCLUSION: COVID-19 pandemic had an influence on the Lublin Eye Bank activities.Fortunately, the pandemic did not have a major impact on the number of donors as well as the corneas collected in our bank.

P25-A123†Indo - German GIZ collaboration - impact and way forward in global eye banking.

PURPOSE: Geographical imbalance in cornea supply is a key feature of global eye banking. Most countries of South Asia particularly India suffer from donor cornea shortage which limits the number of keratoplasties, thereby aggravating the already high burden of removable blindness. The purpose of the project is to identify and cross-pollinate best practices from two leading eye banking institutions in India and Germany, and thereby improve service delivery of both systems. The project is supported by the GIZ Hospital Partnerships funding program on behalf of the Federal Ministry for Economic Cooperation and Development (BMZ) with a co-financing by the Else Kröner-Fresenius Foundation (EKFS). It started in 2021 and will last upto 2023. METHODS: A joint expert group from both organisations conducted a series of workshops to identify the areas of intervention and specific practices to be introduced at the Indian partner's region. The overall increase in cornea collections and transplants, documented systemic improvement measures and research output were defined as the key outcomes. RESULTS: Interim results are presented here. Two interventions identified were expansion of catchment area of cornea collection in India, and improved information management system to monitor the progress and efficiency of the collection centres. Under the former intervention, the hub-and-spoke model from the German partner was introduced to the most populous state of India through establishment of two new cornea collection centres (spokes) for Hospital based Cornea collections. In six months these centres have supplied 79 donor corneas leading to 63 transplants at the hub. Under the latter intervention, the specifications of a baseline data capture and operations management system which can be used in low resource settings are being developed. CONCLUSION: The initiative has shown how best practice from one geography can be adapted and successfully implemented in another geography , Furthermore, the public knowledge resources created in the project can be used by other eye banks to advance eye banking in their respective countries.

P17-A140†Clinical outcomes of the first organ-cultured preloaded DMEK-a single centre studie.

The use of ready-to-use grafts from specialized eye banks might provide a number of benefits, including graft quality control, assured availability at a certain operation time, a decreased likelihood of case cancellation, and a shorter and less sophisticated DMEK surgery, with a resulting lower risk of graft damage. However, it is critical to thoroughly establish the clinical safety of employing these preloaded tissues. Especially since most of the studies were prepared and stored under hypothermic conditions. There are only a few studies on preprepared tissues in organ culture, which are partly controversial.In this prospective study we included patients who received DMEK surgery at the Knappschaft Eye Clinic Sulzbach. Patients received either a preloaded DMEK (pDMEK), prepared five days before surgery in the eye bank, or a conventional, directly before surgery, surgeon-prepared DMEK (sDMEK).The preliminary data show a trend towards more frequent need for rebubbing in the pDMEK group and a statistically non-significant lower postoperative endothelial cell count compared to the sDMEK group. However, the development of visual acuity and decrease in corneal thickness is comparable in both groups.Therefore, we investigated the clinical outcomes of the first organ-cultured preloaded DMEK cases and compared these outcomes with those from our very last cases with surgically loaded tissues from a single centre.

P44-A104†Logistics and results with precut and preloaded graft for DMEK.

PURPOSE: Descemet membrane endothelial keratoplasty (DMEK) preparation is technically demanding and is a limiting factor for uptake of this kind of surgery. Supply methods that simplify the procedure for surgeons are key to increasing uptake. In this talk logistics and outcomes of Eye bank prepared DMEK tissue will be presented. METHODS: Laboratory studies of two different shipping protocols for DMEK (endothelium trifolded inwards and endothelium rolled outwards) will be presented. Clinical outcomes and complications of patients underwent to DMEK surgery with Eye bank prepared or surgeon prepared tissue will be presented. A Cost analysis of eye bank versus surgeon prepared endothelial grafts will be also part of the presentation. RESULTS: There was no difference in endothelial cell viability between surgeon or eye bank prepared tissue. Surgeon-stripped DMEK grafts in the laboratory investigation showed significantly higher elastic modulus and adhesion force compared to prestripped and preloaded tissues (p<0.0001). In the clinical data, rebubbling rates of 48%, 40% and 15% were observed in preloaded, prestripped and surgeon-stripped DMEK grafts, respectively. The cost analysis showed that eye bank prepared tissues had higher surgical expenses compared to those prepared by the surgeon, while the post-operative care expenses were similar between the two groups CONCLUSION: The Eye bank prepared tissues are a valid alternative to Surgeon prepared tissue, however need to be highlighted that with current method there is a decreased adhesion forces and elastic modulus in eye bank prepared tissues that may contribute to increased rebubbling rates.

P02-A121†Precut DSAEK stored in an active storage machine: feasibility study.

PURPOSE: The number of endothelial grafts precut by eye banks increases. Their shelf life is limited to a few days. We previously demonstrated the superiority of an active storage machine (ASM) over organ culture (passive) for whole corneas. AIMS: to measure endothelial viability of precut DSAEK after 3 or 10 days of storage in our ASM in a preclinical study. METHODS: Human pairs of corneas were included. The endothelial cell density (ECD in cells/mm2), and central corneal thickness (CCT in µm) were measured to ensure their initial intra pair comparability. After deswelling (CorneaJet, Eurobio) grafts preparation was performed by cutting the anterior stroma with a Moria linear microkeratome and keeping the anterior lamellae attached during storage. After randomization, one cornea was kept in the corneajet bottle (CJ) and the other was inserted into the ASM allowing a renewal or storage medium (CorneaMax, Eurobio) at 2.6 µL/min with 21 mmHg of pressure in the endothelial chamber. Both group of corneas were stored for 3 or 10 days at 31°C. The final viable ECD (vECD) was determined using the triple staining with Hoechst-Ethidium-Calcein-AM by an independent experimenter in a masked fashion. RESULTS: Initial ECDs were comparable: 2595±878 in ASM versus 2654±954 cells/mm2 in CJ for the 3-days period (n=5 pairs) and 2416±712 in ASM versus 2492±764 cells/mm2 in CJ for the 10-period (n=5 pairs). CCTs were also comparable. The anterior lamellae stayed attached in either the ASM or CJ. vECD was significantly higher in ASM than in CJ with respectively 2062±695 cells/mm2 versus 1632±633 cells/mm2 after 3 days either a cell loss of 20.5% and 38.5% respectively (p=0.0062) and 1082±649 versus 935±691 cells/mm2 for the 10-day period either a cell loss of 132% and 164% respectively (p=0.005). Grafts thickness did not differ after 3 days 219±25 µm in ASM versus 182±39 µm (p=0.063) or 10 days respectively 221±58 µm versus 189±48 µm (p=0.06). CONCLUSION: The storage of precut DSAEKs into the ASM allows a better preservation of grafts without use on deswelling storage medium. Nevertheless, the cell loss remains high after 10 days, suggesting a significant cell stress.

P43-A106†Eyebank stripped vs. Surgeon stripped tissue for DMEK.

During the recent years Descemet membrane endothelial keratoplsty (DMEK) has replaced penetrating keratoplasty and more or less Descemet stripping automated endothelial keraoplasty (DSAEK) as the goldstandard for the treatment of endothlial corneal diseases. Following DMEK the clinical recovery is faster and patients reach higher visual acuities with a lower risk for graft rejection. However, the technique of preparing the graft for DMEK is more demanding and less standardised than the perparation of a DSAEK graft. Therefore, the preparation may take longer and risk of a preparation failure seems higher. For this reason surgeons look for prestripped tissue for DMEK to avoid the potential inconveniences with the graft preparation. However, prestripped tissue might not always be advantageous as the graft might loose endothelial cells during storage and transportation and the surgeon is not aware of the specific properties of the graft. Advantages and disadvantages of eyebank stripped and surgeon stripped tissue will be discussed.

P37-A124†Smile bank - corneal stromal lenticules from relex smile - the new eye bank product.

PURPOSE: The aim of our presentation is to introduce future eye bank product - corneal stromal lenticule from living donors, which can be used for allotransplantation. METHODS: ReLEx (refractive lenticule extraction) SMILE (small incision lenticule extraction) is a common approach in laser eye surgery. It is minimally invasive and flap-free procedure. During this procedure part of corneal stroma (lenticule) is created by femtosecond laser and consequently removed through small incision. The lenticule is basically waste material of the ReLEx SMILE procedure. In the International Eye Bank of Prague, we decided to establish new protocol for lenticule withdrawal, storage and release for transplantation. RESULTS: All donors signed an informed consent, and their serum was tested for the presence of infectious diseases. After ReLEx SMILE procedure the lenticule was stored in container with cryopreservation solution and frozen in the eye bank using the same protocol for frozen amniotic membrane. After 6 months in -80°C tissues were defrosted and examined histologically, using conventional light histology staining and electron microscopy. CONCLUSION: We believe, that lenticule from living donor is a safe and effective tissue, that can be used for many indications and in particular situations represents good alternative to whole donor cornea and amniotic membrane.

P24-A114†Bringing together the eye banking community throughout Europe and beyond - promoting eye donation in Africa.

PURPOSE: It is estimated that globally there are more than 12.7 million corneal blinds with the vast majority of those living in the developing world. There is huge demand for corneal transplants worldwide as currently only one out of 70 patients can be provided with a cornea.Following the spirit of EEBA in bringing together the international eye banking community we present on our efforts and vision in contributing to the elimination of avoidable blindness in Africa by promoting sustainable eye donation programs. METHODS: At the congress of the South African Tissue Bank Association (SATiBA) in November 2022 a dedicated Round Table Discussion takes place on eye donation in Africa, organized by the World Union of Tissue Banking Associations (WUTBA) together with the Global Alliance of Eye Bank Associations (GAEBA), SATiBA and the German Society for Tissue Transplantation (DGFG). Individuals, national and global players in tissue medicine meet aiming to promote and advocate corneal donation in sub-Saharan Africa to establish patient care that is self-sustaining from within the countries.In preparation for the meeting a questionnaire was completed by the participants to understand the current situation in individual countries: Responses by ophthalmologists, tissue bankers, awareness and tissue donation coordinators from Kenya, Uganda, Nigeria, Ethiopia, and South Africa were evaluated. RESULTS: The survey revealed that all countries are establishing national health acts with references to tissue donation or have them in place with regulations still to be detailed. These are fundamental to strengthen confidence in tissue donation and to start developing donation infrastructures. In all countries there is doubt about donation after death showing the need for advocacy towards the public.The aim of the Round Table is creating a momentum of networking and sharing experience to support the African countries in building local infrastructures and becoming independent from tissue imports in the future. CONCLUSION: What frameworks must exist to successfully establish donation programs in Africa? What help can be provided by countries and organizations that have stable donation programs? These and other questions will be attempted at the Round Table. Bringing together experts, bundling synergies, and creating a momentum to promote cornea donation on social, political, and community level will be a step towards the vision of creating a world in which nobody is needlessly visually impaired.

P01-A120†Pre-dissected dmek stored in an active storage machine: feasibility study.

PURPOSE: The number of endothelial grafts precut by eye banks increases. Their shelf life is limited to a few days. We previously demonstrated the superiority of an active storage machine (ASM) over organ culture (passive) for whole corneas. AIMS: To measure the endothelial viability of pre-dissected DMEK after 3 and 10 days of storage in our ASM in a preclinical study. METHODS: Pairs of human corneas were included. The endothelial cell density (ECD in cells/mm2), thickness and transparency of corneas were measured before graft preparation. Descemet's membrane (DM) was peeled using the no-touch technique leaving the graft attached to the center of the cornea (on approx. 1mm2). After randomization, one cornea was kept in organ culture (OC) and the other in the ASM (21 mmHg, 2.6 µL/min) in the same medium (CorneaMax, Eurobio). The final viable ECD was determined using the triple staining with Hoechst-Ethidium-Calcein-AM. In addition, the expression of CD166 and NCAM (lateral membranes), ZO-1 (apical junctions), Na+/K+ ATPase (endothelial pump function) and COX-IV (mitochondrial content) was studied by immunostaining to characterize endothelial cells after the storage. RESULTS: Initial ECDs were comparable: 2185±232 cells/mm2 in the ASM versus 2276±328 in OC for the 3-day period and 2680±416 cells/mm2 in the ASM versus 2644±420 in OC for the 10-day period. The DMs did not fold back in either BR or OC. The viable ECD did not differ significantly between the ASM and OC for either storage period: 2378±501 (ASM) versus 2342±503 (OC) for the 3-day period (n=8 pairs and p=0.624) and 2482±288 (ASM) versus 2579±315 (OC) for the 10-day period (n=5 pairs and p=0.176). Corneas were more transparent and thinner in the ASM than in OC after 3 days (916±86 versus 1193±136µm, p=0.0001) and 10 days (957±128 versus 1220±105µm, p=0.0625). The functional and structural markers studied were expressed in both groups after 3 and 10 days, some better preserved in the ASM. CONCLUSION: The storage of precut DMEKs is possible in ASM and OC for at least 10 days. Interestingly, a pre-dissected endothelium continues to partially exert its pump function into the ASM. In practice, this could allow the stroma to be used for DALK without further deswelling. In addition to improving the storage of whole grafts, the ASM allows the storage of precut DMEKs for up to 10 days with excellent endothelial survival.