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.

Quality Control in the Corneal Bank with Artificial Intelligence: Comparison of a New Deep Learning-based Approach with Conventional Endothelial Cell Counting by the "Rhine-Tec Endothelial Analysis System". / Qualitätskontrolle in der Hornhautbank mit künstlicher Intelligenz: Vergleich eines neuen Deep-Learning-basierten Ansatzes mit der konventionellen Endothelzelldichtenbestimmung durch das "Rhine-Tec Endothelial Analysis System".

Endothelial cell density (ECD) is a crucial parameter for the release of corneal grafts for transplantation. The Lions Eye Bank of Baden-Württemberg uses the "Rhine-Tec Endothelial Analysis System" for ECD quantification, which is based on a fixed counting frame method considering only a small sample of 15 to 40 endothelial cells. The measurement result therefore depends on the frame placement and manual correction of the cells counted within the frame. To increase the sample size and create higher objectivity, we developed a new method based on "deep learning" that automatically detects all visible endothelial cells in the image. This study aims to compare this new method with the conventional Rhine-Tec system. 9375 archived phase-contrast microscopic images of consecutive grafts from the Lions Eye Bank were evaluated with the deep learning method and compared with the corresponding archived analyses of the Rhine-Tec system. Means, Bland-Altman and correlation analyses were compared. Comparable results were obtained for both methods. The mean difference between the Rhine-Tec system and the deep learning method was only - 23 cells/mm2 (95% confidence interval - 29 to - 17). There was a statistically significant positive correlation between the two methods, with a correlation coefficient of 0.748. What was striking in the Bland-Altman analysis were clustered deviations in the cell density range between 2000 and 2500 cells/mm2 - with higher values in the Rhine-Tec system. The comparable results for cell density measurement values underline the validity of the deep learning-based method. The deviations around the formal threshold for graft release of 2000 cells/mm2 are most likely explained by the higher objectivity of the deep learning method and the fact that measurement frames and manual corrections were specifically selected to reach the formal threshold of 2000 cells/mm2 when the full area endothelial quality was good. This full area assessment of the graft endothelium cannot currently be replaced by deep learning methods and remains the most important basis for graft release for keratoplasty.

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.

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

PURPOSE: 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. METHODS: 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 24 h after transfer to thinning medium. Samples were tested for 7 days using the BACTEC FX system. Corneas remained in quarantine until clearance was obtained. RESULTS: 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 55 years, 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 25.5 h (mean = 13.5 ± 7.3) and death to preservation time ranged from 4.1 to 27.5 h (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. CONCLUSION: Microbiological screening of corneas stored in OCM at LEBWA showed a very low rate of positive cultures with no predictive donor characteristics.

Ophthalmologists' perspectives on corneal transplantation and donation: a survey from Türkiye.

PURPOSE: To evaluate ophthalmologists' interest and opinions regarding corneal transplantation and donation in Türkiye. MATERIAL AND METHODS: An online questionnaire was prepared using Google Forms, and the electronic link to this questionnaire was sent via WhatsApp to ophthalmologists working in Türkiye. Eighteen open-ended/multiple-choice questions were asked about ophthalmologists' demographic information and their opinions regarding corneal transplantation and donation. The answers were analyzed by transferring the data to Excel. RESULTS: A total of 195 ophthalmologists participated in the survey. While 68.6% of them stated that they wanted to donate their corneas, 21.1% stated that they were undecided, and 10.3% did not want to donate their corneas. While 93.8% of the participants agreed to have a cornea transplant in case of need, 5.7% of them stated that they were undecided, and 0.5% said that they would not accept a cornea transplant. The most frequent (90.5%) reason for being willing to donate one's cornea was to give hope to patients with low vision. The most frequent (46.2%) reason for not wanting to donate one's cornea was the unwillingness to have one's body/eye integrity impaired. The vast majority (80.8%) of the participants thought that there was not enough corneal donation in Türkiye and that this was mostly (85.9%) due to cultural and/or religious reasons. CONCLUSIONS: Even in a sample with a high level of education and the most knowledge about corneal transplantation, the willingness to donate corneas may remain below the expected rates. Therefore, it is necessary to alleviate unrealistic concerns and prejudices about corneal donation and transplantation.

[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.

The role of eye banking with cell-based therapies.

PURPOSE OF REVIEW: Cell-based therapies are an exciting new frontier in managing corneal diseases. The introduction of these novel therapies may provide new alternatives to corneal transplantation and decrease the dependence on donor corneal tissue. These changes have the potential to significantly impact eye banking in the future. RECENT FINDINGS: The current article reviews current research involving cell-based therapy for treating corneal disorders, including cultivated limbal stem cell transplantation, limbal mesenchymal stem cells for stromal regeneration, and the use of human-cultivated endothelial cells. We will look at barriers to the development and implementation of these therapies. SUMMARY: As corneal surgery expands to include cell-based therapies; eye banks will need to redefine their role to support the everchanging landscape of corneal surgery and the decreased demand for corneal donor tissue.

In situ donor keratometry in deceased patients as a novel screening technique for eye banking.

PURPOSE: To investigate the potential role of keratometry on whole globes in situ of deceased patients by assessing its repeatability and comparing it with sterile donor tomography after excision and preservation in organ culture. METHODS: A sequence of 5 measurements was taken from 40 eyes in situ of deceased patients < 24 h after death using the portable Retinomax K-plus 3 (Bon, Tokyo, Japan). Keratometry of whole globes in situ, from which sclerocorneal discs were taken for organ culture, was compared to those obtained after measuring these sclerocorneal disks through their cell culture flask in medium I after 5 ± 4 days using the anterior segment optical coherence tomograph Casia 2 (Tomey Corp., Nagoya, Japan), and to 964 different donor corneas in medium II. RESULTS: Cronbach's alpha of the in situ keratometry was 0.891 and 0.942 for the steepest and flattest corneal power (P). The steepest (44.5D) and flattest (41.1D) P as well as the astigmatism (3.4D) of in situ corneas remained unchanged after preserving sclerocorneal discs in medium I (respectively 44.7D [p = 0.09]; 41.4D [p = 0.17]; 3.3D [p = 0.09]). The comparison of the in situ values with the 964 measured different donor corneas in medium II showed significantly (p < 0.001) higher P at the steep (45.4D) and flat (43.9D) meridian and smaller astigmatism (1.4D) for sterile donor tomography. CONCLUSIONS: Measuring deceased patients' eyes in situ with the portable Retinomax K-plus 3 represents a feasible and reliably repeatable screening method in the eye bank. In comparison to donor tomography in medium I, it measures a similar power and astigmatism.

Preparation of endothelial keratoplasty lamellae from donated whole eyes post vitreous humour aspiration at the central eye bank of Iran.

To compare the endothelial parameters and thickness profiles of endothelial keratoplasty (EK) lamellae from donated whole eyes post vitreous humour aspiration (VHA) with those prepared from their mate control eyes (without VHA). Between March 2019 and March 2020, a few steps were added when aspirating the vitreous humour and also before dissecting the corneal tissue with microkeratome. EK lamellae were prepared from whole eyes that underwent VHA and their corresponding endothelial and thickness profiles were compared with those prepared from their respective fellow control eyes. Post-operative data in terms of graft attachment and clarity and the rate of reoperation were also reviewed. 115 eyes that underwent VHA and 115 of their respective fellow eyes were enrolled. No significant difference was noted in the endothelial parameters between the two groups. Mean central thickness of the EK lamellae and increase of thickness towards the periphery were not significantly different between the groups. Both groups did not show a significant difference with respect to the anticipated dissection depth, post-operative graft clarity, graft attachment, and the rate of regraft. This study demonstrates that aspirating vitreous humour has no adverse effect on the endothelial and thickness profiles of the EK lamellae that are prepared from these donated whole eyes, once the specific steps outlined by the eye bank are adhered to when aspirating the vitreous humor before performing the microkeratome dissection. The success rate of the grafted lamellae was comparable between the study groups.

[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.

Advances in eye banking and corneal tissue processing.

PURPOSE OF REVIEW: Eye bank processing of donor corneal tissue has helped to revolutionize and popularize newer corneal transplantation surgeries. In particular, Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) have benefited from eye banks preparing donor corneal tissue in advance of the surgery. As a result of these eye banking advances, surgeons have been able to rapidly adopt these new techniques. RECENT FINDINGS: This article reviews the techniques that are now being utilized to prepare donor tissue for endothelial keratoplasty (EK) with a focus on Ultrathin-DSAEK, prestamped, prestained, preloaded DMEK tissue, and advancements to improve the safety of donor corneal tissue. SUMMARY: Collaborative efforts between surgeons and eye banks have been at the core of advances that have been made in EK over the past decade. Corneal surgery starts in the eye bank, and it is important for corneal surgeons to understand the process and appreciate the efforts that have been made to provide them with suitable and safe donor corneal tissue.

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.

BACKGROUND: With 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. METHODS: Data 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 . RESULTS: A 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 keratoplasties 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). CONCLUSION: Despite 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.

Canadian demand and access to corneal transplantation: a provincial comparison.

To gather information from stakeholders involved in corneal donation and transplantation to inform discussion at the "National Consensus Forum on Improving Cornea Donation and Transplantation Access in Canada" held in February 2020, survey questions were posed to eye banks, transplanting ophthalmologists and organ donation organizations across Canada to learn more about demand, wait times, and access to tissue for transplant. The survey response rate was one hundred percent (100%) for eye banks and organ donation organizations while 64 percent (64%) of transplant ophthalmologists provided feedback. A number of opportunities for improvement were identified including: demand forecasting; infrastructure and strategies to align supply with demand; data collection and benchmarking of wait times for assessment and transplant to support consistency, equitability and transparency in access; and national collaboration in the development of a data strategy to accurately measure demand and access to cornea transplants in a consistent manner across all provinces to facilitate equity in access nationally.

Gram stain and addition of amphotericin B to improve the microbial safety of human donor corneas.

To determine the effectiveness of two methods to improve the microbial safety of human corneas preserved in organ culture. We compared the number of positive preservation solutions of corneas in organ culture in which the initial short-term hypothermic corneal maintenance solution was supplemented with amphotericin B 2.5 µg/mL and the historical data of microbial test results (2015-2019). In addition, we appraised the efficacy of Gram stain to detect bacterial or fungal contamination in the organ culture solutions of corneas from at-risk donors compared to the culture tests of corneas from not-at-risk donors. Statistical analysis was performed using STATA and statistical significance set at p < 0.05. The number of positive culture tests after preservation was 15 (0.5%) in 2020 compared to a mean of 37 (1.2%) in the period 2015-2019 (p < 0.01), with 10 (1.0%) positive samples in the cohort of 998 corneas from at-risk donors and 5 (0.2%) in the 2046 corneas from not-at-risk donors (p < 0.01). All corneas from at-risk donors tested positive at Gram stain and the results were available 1-3 days before those of the conventional culture tests. Amphotericin B supplementation in the short-term maintenance solution markedly reduced the number of positive microbial tests after organ culture and the early detection of contaminants, including slow-growing microorganisms, by Gram stain before the standard culture results. This meant fewer corneas being discarded and a greater likelihood of preventing post-graft infections.

Reliability and efficiency of corneal thickness measurements using sterile donor tomography in the eye bank.

To evaluate the reliability and efficiency of sterile pachymetric measurements of donor corneas based on tomographic data using two different methods: a "manual" and a "(semi-)automated" method. Twenty-five (25) donor corneas (50%) stored in MI and 25 (50%) in MII were imaged 5 times consecutively using an anterior segment OCT (AS-OCT). The central corneal thickness (CCT) was measured both with the manual measurement tool of the AS-OCT (= CCTm) and with a MATLAB self-programmed software allowing (semi-)automated analysis (= CCTa). We analyzed the reliability of CCTm and CCTa using Cronbach´s alpha (α) and Wilcoxon signed-Rank Test. Concerning CCTm, 68 measurements (54.4%) in MI and 46 (36.8%) in MII presented distortions in the imaged 3D-volumes and were discarded. Concerning CCTa, 5 (4%) in MI and 1 (0.8%) in MII were not analyzable. The mean (± SD) CCTm was 1129 ± 6.8 in MI and 820 ± 5.1 µm in MII. The mean CCTa was 1149 ± 2.7 and 811 ± 2.4 µm, respectively. Both methods showed a high reliability with a Cronbach´s α for CCTm of 1.0 (MI/MII) and for CCTa of 0.99 (MI) and 1.0 (MII). Nevertheless, the mean SD of the 5 measurements was significantly higher for CCTm compared to CCTa in MI (p = 0.03), but not in MII (p = 0.92). Sterile donor tomography proves to be highly reliable for assessment of CCT with both methods. However, due to frequent distortions regarding the manual method, the (semi-)automated method is more efficient and should be preferred.

Transcriptional Profiling Provides New Insights into Organ Culture-Induced Changes in Human Donor Corneas.

Corneal transplantation is one of the most common forms of tissue transplantation worldwide. Donor corneal tissue used in transplantation is provided by eye banks, which store the tissue in culture medium after procurement. To date, the effects of cell culture on human corneal tissue have not been fully elucidated. Using the 3' RNA sequencing method for massive analysis of cDNA ends (MACE), we show that cultivation of corneal tissue leads to significant changes in a variety of molecular processes in human corneal tissue that go well beyond aspects of previously known culture effects. Functionally grouped network analysis revealed nine major groups of biological processes that were affected by corneal organ culture, among them keratinization, hypoxia, and angiogenesis, with genes from each group being affected by culture time. A cell type deconvolution analysis revealed significant modulations of the corneal immune cell profile in a time dependent manner. The results suggest that current culture conditions should be further refined and that prolonged cultivation may be detrimental. Recently, we showed that MACE enables transcriptional profiling of formalin-fixed and paraffin-embedded (FFPE) conjunctival tissue with high accuracy even after more than 10 years of storage. Here we demonstrate that MACE provides comparable results for native and FFPE corneal tissue, confirming that the technology is suitable for transcriptome analysis of a wide range of archived diseased corneal samples stored in histological archives. Finally, our data underscore the feasibility of bioinformatics cell-type enrichment analysis in bulk RNA-seq data to profile immune cell composition in fixed and archived corneal tissue samples, for which RNA-seq analysis of individual cells is often not possible.

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. / Einfluss der Einführung des Qualitätsmanagementsystems auf die Verwerfungsrate und -gründe von menschlichem organkultivierten Spendergewebe der LIONS-Hornhautbank Saar-Lor-Lux, Trier/Westpfalz von 2006 bis 2016.

BACKGROUND: 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. MATERIAL AND METHODS: 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. OUTCOME: 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). CONCLUSION: 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.

Surgeons preferences in descemet membrane endothelial keratoplasty (DMEK).

AIM: To explore the attitudes, preferences, and barriers of DMEK among corneal specialists in Saudi Arabia. METHOD: An anonymous survey was sent through an online platform to members of the Saudi Ophthalmological Society. The survey was designed to capture data covering: demographic data, practice patterns of keratoplasty techniques, DMEK technique preferences, barriers, and facilitators to performing DMEK. RESULTS: Thirty-five (33% response rate) surgeons participated in the questionnaire. Sixty-eight percent were in practice for less than or equal to 10 years. Thirteen surgeons were performing DMEK. Participating in any training capacity was observed among surgeons who performed DMEK (92%). The main selection criteria for this procedure were patients with normal anterior chamber anatomy (77%). The main barrier against DMEK adoption among surgeons who do not perform the procedure was the lack of experience (91%). Strategies to help begin performing DMEK were eye banks support (prepared grafts, backup tissue for inadvertent loss), access to wet-lab training courses, and higher surgical volume. CONCLUSION: DMEK is not highly performed among corneal specialists in Saudi Arabia; however, there is evident interest in adopting this technique. Strategies toward filling the gap of lacking experience would facilitate the adoption of the procedure. Eye banks play a crucial role by providing prepared tissues, which would lessen part of the technical difficulty.

Updated safety precautions and guidance on eye banking procedures during the coronavirus disease 2019 pandemic.

PURPOSE OF REVIEW: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly infectious coronavirus causing the COVID-19 pandemic. Although airborne spread through infectious respiratory droplets is the primary source of transmission, recent literature has suggested the ocular surface may be able to harbor viral particles. Here, we aim to discuss how SARS-CoV-2 affects the ocular surface and updated guidance on how SARS-CoV-2 transmission should be considered in the setting of eye banking and corneal transplantation procedures. RECENT FINDINGS: SARS-CoV-2 RNA can be found on the ocular surface, which may suggest the eye as a site of viral replication. However, there is poor correlation between PCR positivity on the ocular surface and ocular symptoms. To date, although viral particles can be found on the ocular surface, use of standard antiseptic procedures during corneal tissue procurement appears to sufficiently reduce viral load. In addition, preprocedure testing may further decrease the chances of transplanting an infected cornea without significantly impacting the overall accessibility to corneal tissue by decreasing the donor pool. SUMMARY: Corneal transplantation remains a well tolerated and highly successful procedure with no evidence of viral transmission with transplantation. Although the ocular surface has the required receptors to allow for viral replication, there is no clear evidence that the eye is a site for primary viral infection.

Cost analysis of eye bank versus surgeon prepared endothelial grafts.

BACKGROUND: Selective lamellar corneal transplantation (keratoplasty) has overtaken full thickness penetrating keratoplasty as the graft choice for endothelial failure. Even more recently eye bank prepared tissues are becoming increasing popular as a way to reduce the risks of tissue loss and stress during endothelial keratoplasty preparation in the surgical theatre. This study compares costs between surgeon and eye bank prepared tissues for Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK). METHODS: Retrospective study conducted at the Royal Liverpool University Hospital including endothelial keratoplasties with a minimum of 6 months follow-up time. Cost analysis included surgical expenses, tissue acquisition fees, cost of patient's ward admission and out-patient expenses, including cost of re-bubbling procedures, costs of visits, anterior segment imaging and optometrist visits within the first 6 months follow-up. RESULTS: Ninety-eight eyes of 98 patients were included in the study of which 42 underwent DSAEK surgery and 56 DMEK surgery. Cost analysis of surgical expenses in the DSAEK group showed a significant difference between using surgeon prepared and eye bank prepared tissue (£3866 ± 296 and £4389 ± 360, respectively; p < 0.01) and the same was found in the DMEK group (£3682 ± 167 and £4162 ± 167 for surgeon prepared and eye bank prepared tissues, respectively; p < 0.01). Cost of out-patient visits did not differ significantly in either group. CONCLUSIONS: At the Royal Liverpool University Hospital, 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.