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.

Factors associated with the quality of corneas retrieved for transplantation by Eye Banks: a scoping review protocol.

INTRODUCTION: The cornea is an avascular and transparent layer of connective tissue crucial to retinal image quality. Diseases can impair its quality, affecting vision. Keratoplasty is the only therapy capable of restoring vision quality in severe corneal involvement. Despite the established practice of transplantation, access to corneal tissue is limited in many places, and the quality of retrieved corneas is not always adequate, resulting in disqualification. Not all factors affecting tissue quality are fully understood due to the multifactorial nature of processes and variations in procedures globally. OBJECTIVE: The objective is to map the global literature to establish the factors associated with the clinical and sociodemographic conditions of donors, and the conditions inherent in the processing of corneas that can influence the quality of this tissue for transplantation purposes. METHODS AND ANALYSIS: A scoping review will be developed based on the methodological framework of the Joanna Briggs Institute. The scientific report will follow the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension checklist for Scoping Reviews. Searches will be conducted in 30 indexed and 12 grey literature databases, without time or location restrictions. The selection of studies will be carried out in three distinct phases: screening, eligibility and inclusion. After defining the sample, data from the selected studies will be systematically extracted into an electronic spreadsheet. The results will be presented descriptively through tables and graphs of absolute and relative frequency. In addition, the PRISMA Scoping Review flow chart will be presented to present the process of searching, including and excluding articles and documents. ETHICS AND DISSEMINATION: This scoping review study does not require prior ethical approval as it uses publicly available and already published studies. The research protocol is registered in the Open Science Framework (osf.io/bw6r7). The findings will be submitted for publication in peer-reviewed scientific journals and presented at ophthalmology and/or transplantation conferences through oral presentations or posters.

Utility of a Model to Predict Endothelial Cell Density of Donor Corneas to Determine Suitability for Transplantation.

Purpose: In Germany, approximately one-third of the harvested donor corneas are not suitable for transplantation, mostly due to insufficient endothelial cell density (ECD). The ECD can only be reliably determined after harvesting and processing of the cornea. Our group has previously developed a predictive model for corneal ECD: \( {Predicted\, ECD} = 2919-6^{\ast}\;{age}\; [{years}]-189\; [{if\, male}]\\ -7^{\ast}\;{death-to-explantation\, interval\,} [{hours}]\\ - 378\; [{if\, pseudophakic}] \;{cells/mm}^2 \). Methods: A total of 2.999 consecutive donor corneas harvested between 2017 and 2021 from the Eye Bank of Rhineland-Palatinate in Mainz, Germany, were included. An actual ECD of >2000 cells/mm2 was defined as the cutoff value. To evaluate the clinical utility of the prognostic model as a screening instrument for transplant eligibility in an independent cohort, we performed a decision curve analysis. Results: The median predicted ECD was 2061 cells/mm2 (interquartile range [IQR] = 1834 to 2221), whereas the median actual ECD was 2377 cells/mm2 (IQR = 1907 to 2624). There was a positive correlation between predicted and actual ECD (correlation coefficient = 0.411; P < 0.01). Our predictive model for ECD is a strong predictor for an actual ECD greater than 2000 (odds ratio = 1.374, 95% confidence interval [CI]) per 100 cells; P < 0.001, area under the curve [AUC] of 0.73). Decision curve analysis showed that the predictive model yielded a positive net benefit in clinical settings. Conclusions: Decision curve analysis demonstrated a positive net benefit of the ECD predictive model in clinical settings with limited eye bank resources. Translational Relevance: In possible scenarios where a choice between corneal grafts is required, or in countries with limited eye bank infrastructure and staff, the initial estimate of ECD from the formula may be beneficial.

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.

Tissue Loss During Eye Bank Processing.

This comparative effectiveness research study assesses the rate of tissue loss in ultrathin Descemet stripping automated endothelial keratoplasty grafts vs descemet membrane endothelial keratoplasty grafts during eye bank processing.

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.

Real-time monitoring of riboflavin concentration using different clinically available ophthalmic formulations for epi-off and epi-on corneal cross-linking.

PURPOSE: To assess the feasibility of theranostics to determine the riboflavin concentration in the cornea using clinically available ophthalmic formulations during epithelium-off (epi-off) and transepithelial (epi-on) corneal cross-linking procedures. METHODS: Thirty-two eye bank human donor corneas were equally randomized in eight groups; groups 1 to 3 and groups 4 to 8 underwent epi-off and epi-on delivery of riboflavin respectively. Riboflavin ophthalmic solutions were applied onto the cornea according to the manufacturers' instructions. The amount of riboflavin into the cornea was estimated, at preset time intervals during imbibition time, using theranostic UV-A device (C4V CHROMO4VIS, Regensight srl, Italy) and expressed as riboflavin score (d.u.). Measurements of corneal riboflavin concentration (expressed as µg/cm3) were also performed by spectroscopy absorbance technique (AvaLight-DH-S-BAL, Avantes) for external validation of theranostic measurements. RESULTS: At the end of imbibition time in epi-off delivery protocols, the average riboflavin score ranged from 0.77 ± 0.38 (the average corneal riboflavin concentration was 213 ± 190 µg/cm3) to 1.79 ± 0.07 (554 ± 103 µg/cm3). In epi-on delivery protocols, the average riboflavin score ranged from 0.17 ± 0.01 to 0.67 ± 0.19 (corneal riboflavin concentration ranged from 6 ± 5 µg/cm3 to 122 ± 39 µg/cm3) at the end of imbibition time. A statistically significant linear correlation (P ≤ 0.05) was found between the theranostic and spectrophotometry measurements in all groups. CONCLUSIONS: Real-time theranostic imaging provided an accurate strategy for assessing permeation of riboflavin into the human cornea during the imbibition phase of corneal cross-linking, regardless of delivery protocol. A large variability in corneal riboflavin concentration exists between clinically available ophthalmic formulations both in epi-off and epi-on delivery protocols.

Quality and applicability of cadaveric donor eyes for molecular biology research: An Indian experience.

PURPOSE: Human ocular tissue banking plays an important part in the advancement of translational research for identifying the molecular processes involved in disease etiology and pathogenesis. Timely obtaining a good-quality ocular tissue from a cadaveric donor is exceedingly difficult, especially in remote areas, with a variable transportation time (within 12-24 h), raising concerns about RNA quality and its subsequent applications. Therefore, we assessed the utility of retinal tissues from cadaver donor and enucleated eyes based on the RNA quality and gene expression by real-time polymerase chain reaction (PCR). SETTINGS AND DESIGN: Prospective study. METHODS: Retina tissues were separated from the donor/enucleated eyes received in the eye bank within 24 h of death (n = 15) and within an hour from OR (n = 3), respectively, and stored immediately at -80 degree. RNA was isolated using trizol, and the quantity and quality were assessed using Qubit and agarose gel electrophoresis, respectively. QPCR was performed for measuring the expression of different retinal-specific genes. The cellular viability of the retina was assessed by establishing explant primary cell cultures. STATISTICAL ANALYSIS: The data were calculated as an average of normalised Ct values ± standard error of the mean. RESULTS: RNA obtained from cadaveric tissues despite being partially degraded showed a uniform strong gene expression of several retinal-specific genes such as PAX6, RHO, TUBB3, CRX , and ALDH1L1 . The primary cultures established from cadaveric tissues showed viable cells. CONCLUSION: The cadaver donor tissues collected within 24 hours of death can be effectively utilized for gene expression profiling.

The expanding roles of eye banks in India: Past, present, and future.

This review highlights the evolution in the scope of eye banking activities in India. The roles and responsibilities of the eye banks have expanded to match the requirements and necessities that arose because of advancements in keratoplasty techniques and the need for corneal surgeons. Adoption of different types of corneal preservation solutions and methods of donor cornea preservation was a consequence of the changing and unprecedented times. The growth of eye banking in India has been a commendable journey and has placed the country in an "almost sufficient" category in eye banking and corneal transplantation. There exists a potential to reach the status of cornea surplus country in the future. The rules and laws governing eye banking operations need dynamic amendments based on the trends in keratoplasty, surgical practice patterns, and status of self-sufficiency. Newer technological advances and quality measures must be adopted in donor cornea evaluation and tissue preparation. Research should be integrated as an important component of eye banking, especially in developing novel methods of donor preservation, and evaluating and validating the existing and changing practices of eye banking.

Hospital corneal retrieval program: A long way to go.

PURPOSE: The Hospital Corneal Retrieval Program (HCRP) aims to counsel and encourage the family of a critically ill or deceased person in the hospital for eye donation. Adequately sensitized health-care workers (HCWs) may play a pivotal role in boosting HCRP. STUDY DESIGN: Multicentric, cross-sectional, descriptive study. METHODS: Study participants included all HCWs of three medical colleges, including one with eye bank and corneal transplant services. A pretested, structured questionnaire was used to record the awareness, knowledge, and attitude about eye donation among HCWs. The expected outcome was to seek differences in awareness, if any, among medical and paramedical workers of medical colleges with (group A) or without (group B) eye bank and corneal transplant facilities. RESULTS: Of the 4060 study participants, 2100 HCWs were in group A and the rest (1960) were in group B. For eight out of 13 questions assessing awareness and perception, a statistically insignificant difference in responses was observed between the two groups. Regarding questions related to attitude, although the majority of HCWs in both groups were comfortable talking about eye donation, they did feel that counseling relatives of a terminally ill patient about eye donation was insensitive. Less than half of HCWs showed a willingness to donate eyes, and about half of the participants wanted to acquire more knowledge about eye donation. CONCLUSION: Awareness regarding eye donation among HCWs was mostly found to be at dismal levels, irrespective of whether they worked in an institute with or without eye bank and corneal transplant services. This warrants an accelerated effort at sensitizing HCWs as a strengthening measure for HCRP.

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.

[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.

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.

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.

Preloaded DMEK with endo-in technique: Standardizing and minimizing the learning curve over 5 years using 599 corneal tissues.

PURPOSE: To report the outcomes of standardizing pre-loaded DMEK with endothelium-inwards and its associated learning curve. METHODS: Between 2017 and 2021, a total of 599 tissues were stripped using 'trephine and strip' method and loaded by folding the tissue as a taco-fold with endothelium-inwards. The folded tissues were pulled inside the funnel of a 2.2 mm IOL cartridge and stored for the desired number of days in organ culture media supplemented with dextran. Donor characteristics, endothelial cell loss (ECL) and mortality assessed by trypan blue positivity before and after stripping, and eventful cases during stripping/loading were recorded. RESULTS: The tissues found unsuitable for transplant after stripping (6.7%) were significantly higher compared with loading (0.67%). Central or peripheral tears, fragility of the tissues, and insufficient endothelial cell density mainly attributed towards the discard rate. Mean ECL from pre-stripping to post-stripping was 0.27% with endothelial cell mortality of 0.64% at the end of stripping. Cumulative endothelial mortality fold change (pre-strip to post-strip) was high in the first two years of operation (18.9%), which reduced to 5.1% in the following three years with significant difference (p = 0.0352). Average tissue wastage (3 operators) from first 1-150 tissues was 3%, which significantly reduced to 0.9% after achieving the learning curve (151-250) (p = 0.0492). CONCLUSION: DMEK graft preparation requires a learning curve. However, an operator with DMEK stripping skills can easily adapt to pre-loading a DMEK graft in endothelium-inwards fashion with minimal learning curve.

Impact of cleanroom status on the reasons for discarding organ-cultured corneal transplants in a modern eye bank - More donor corneas thanks to astronaut suit?

PURPOSE: This study investigated the influence of cleanroom conditions on the discard rates of donor corneas in a German university eye bank. METHODS: Discard rates were analysed from 2017 to 2020 at the LIONS Cornea Bank at Saarland University Medical Center. 1941 corneas from 971 donors were included. 1262 corneas (65.1%) were stored in a class D cleanroom from 2017 to 2019 and processed in a cleanroom class A sterile bank (group 1). 679 corneas (34.9%) were continuously stored in a class B cleanroom and processed in a class A cleanroom safety cabinet in the same room from 2019 to 2020 (group 2). The target parameter of this work was the number of contamination-related discards. Although they cannot be influenced by the spatial conditions, the discards due to insufficient endothelial quality, serology, contraindications, scars and technical causes were also recorded. Statistical analysis was performed using SPSS and various testing procedures. RESULTS: In group 1, significantly more corneas were discarded due to positive serology (6.9%|3.8%, p = 0.020). There was no significant change between both groups for either contamination or the other reasons for discard. CONCLUSION: Optimization of hygiene standards from cleanroom class D to B did not reduce contamination. Serology, endothelial quality, medical contraindications and the presence of scars cannot be influenced by cleanroom conditions.

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.