Suitability of Corneal Tissue for Transplantation Derived From Violent Death: A 10-Year Analysis

A composite hydrogel membrane with shape and water retention for corneal tissue engineering

Tissue engineering (TE) cornea is one of the most potential alternatives to the shortage of corneal donors in cornea transplantation. Sodium alginate (SA) hydrogel is commonly used as scaffold in TE. Herein, we present an approach to construct a composite hydrogel, which with SA fiber skeleton structure for shape retention and gelatin surface modification for water retention. The light transmittance, water retention rate, and swelling rate of hydrogels were characterized, and the tensile mechanical properties were also investigated. Keratinocytes were treated with material extract liquor and the results showed that the gelatin modified SA hydrogel has good cytocompatibility. Furthermore, human corneal stromal fibroblasts (HCSFs) from the lenticules were implanted on the surface of gels, and the SA-gelatin hydrogel significantly improved the adhesion and spreading of HCSFs. Finally, we discussed the improvement and application prospect of the composite hydrogel as cornea equivalents.

Impact of the COVID-19 pandemic on the trends in corneal donor mortality data from Eye Bank records in India

Purpose:

To describe the causes and trends of corneal donor mortality from eye bank data in India during the coronavirus disease 2019 (COVID-19) pandemic.

Methods:

This retrospective eye bank-based study included 13,529 donors who donated their cornea between January 2018 and December 2021. Donors in whom the cause of mortality was documented were included as cases. The data were collected from the eye bank records.

Results:

Overall, 13,529 corneal donors were included in the study. Most of the donors were males (69.71%). The mean age of the donors was 51.55 ± 20.54 years, whereas the median age was 51 (inter-quartile range: 35–68) years. The mean age of males (49.3 ± 19.47 years) was lesser than the mean age of females (56.72 ± 21.94 years) at the time of donation. The most common age group at the time of donation was during the sixth decade of life with 2,139 (15.81%) donors. The mean age of the donors decreased by a decade from 54.95 ± 20.51 years in 2018 to 44.35 ± 18.88 years in 2021. The most common cause of donor mortality was cardio-respiratory arrest in 5,190 (38.36%) donors and trauma in 3,469 (25.64%) donors, followed by suicide in 2,790 (20.62%) donors. The trend of cardio-respiratory arrest decreased from 53.01% to 9.5% (p = <0.00001), whereas the trends of trauma increased from 21.93% to 36% (p = <0.00001) and suicide increased from 12.71% to 36.41% (p = <0.00001) between 2018 and 2021.

Conclusion:

Corneal donors are more commonly males in their sixth decade of life. The most common cause of donor mortality was related to cardio-respiratory arrest with a concerning rising trend in suicide cases over the years seen significantly during the pandemic.

Cornea donation process and tissue quality for transplantation

Introduction

The quality of the corneal tissue can be influenced by several factors inherent to the recipient, donor, and to the donation and transplantation process. The donated corneal tissue can be classified by its quality as excellent, good, regular, bad, or unacceptable for transplantation, evaluating it in a slit lamp.

Objective

To analyze the relationship between the clinical and sociodemographic variables of the donors and the donation process and the classification of the quality of the corneal tissue collected for transplantation.

Methods

This is an epidemiologic study, retrospective cohort type, which addressed the process of cornea donation by the Human Eye Tissue Bank in a reference service in Northeast Brazil. The sample consisted of corneas processed by the Human Eye Tissue Bank of Rio Grande do Norte (n = 419). For descriptive and inferential analysis, the study used the Statistical Package for the Social Sciences (SPSS) software, version 25.0, and considered a significance level of 0.05. Logistic regression analysis was used for the adjustment of the final model.

Results

It was verified that the epidemiological profile showed a prevalence of individuals with a mean age of 42.54 years old, male (73.99%), and living in the metropolitan region of the state capital (75.66%). When analyzing the relationship between the clinical and sociodemographic variables of the donors, it was identified that those aged 45 years old or less had better quality corneas (excellent and good), while the chronological variables were predictive factors for corneas of regular and bad qualities.

Conclusion

The identification of the factors inherent to the donation process and predictors of corneal tissue quality contribute to minimizing the risk of transplantation and to a better ocular prognosis.

Factors influencing endothelial cell density of corneas for transplantation

To evaluate factors affecting corneal endothelial cell density (ECD) under enucleation and preservation time studies at Eye Bank of the Federal District of Brazil. We conducted a case-control study collecting data from 1128 corneas where death-to-enucleation time and enucleation-to-preservation time were within 24 h. Low cell count were those corneas with an ECD less than 2000 cells/mm² and high cell count was defined as those with ECD greater than 2000 cells/mm². We calculated the independent risk factors related to: cause of death, donor age, death-to-enucleation time, enucleation-to-preservation time and primary graft failure. Correlation analysis was used to assess which parameters influence ECD: death-to-enucleation time, enucleation-to-preservation time, average cell area (AVE), coefficient of variation and percentage of hexagonal cells. Of the total number of corneas, 1004 had ECD data and were selected for the study. 87.4% (n = 877) had high cell counts with 2699 ± 412 cells/mm². The mean donor age was 38.8 ± 16 years. The most common causes of death were external causes (48.6%, n = 488). Longer times from death-to-enucleation, up to 24 h were not associated with a decrease in ECD (OR 0.58; P = 0.44) or risk of graft survival (P = 0.74). Enucleation-to-preservation intervals greater than 12 h showed increased risk of graft survival (P = 0.04). AVE was the main parameter for ECD (R² = 0.96, P < 0.001). The overall graft survival rate was 98.2% (n = 761). Donors with 40 years of age and above did not present a higher risk of graft survival (P = 0.09). We suggest that the maximum time from death-to-enucleation should be 24 h, assuming the body has been refrigerated after 6 h; and from enucleation-to-preservation time of 12 h, followed by proper processing and cornea morphology examination.

Corneal Donor Profile and Evolution of Corneal Donation in a Brazilian State Where the Number of Individuals on the Waiting List Reached Zero But Increased Again

BACKGROUND

In most countries, the amount of corneal graft tissue available for transplantation is insufficient to meet demand. In 2010, there were 459 patients on the waiting list for corneal transplantation (WLCT) in Espirito Santo (ES), a Brazilian state with 3,885,000 inhabitants. Several strategies were implemented to reduce the number of individuals on the WLCT, which reached zero in 2011. Studies on the evolution of corneal donation contribute to reducing the WLCT worldwide. The aim of this study was to describe the evolution of corneal donation in ES and the profile of corneal donors from 2010 to 2013.

METHODS

This was a retrospective study. The data were collected from records referring to donations of corneas and from the archives of the Center for Organ Procurement and Distribution of ES. Statistical software was used to perform descriptive analysis of the data.

RESULTS

The sample consisted of 1359 donors, aged 46.82 ± 17.32 (mean ± standard deviation), 70.1% of whom were male. Most of the consent forms for donation were signed by the sons of the donors. In 2011, there was a major increase (105%) in the number of corneal transplants compared with 2010; consequently, the number of patients on the WLCT reached zero, but increased again, reaching 139 patients in 2013.

CONCLUSION

This study shows that strategies to increase corneal donations should be continued even after reduction or elimination waiting time on the WLCT.

Deceased tissue donor serology and molecular testing for HIV, hepatitis B and hepatitis C viruses: a lack of cadaveric validated tests

Vital to patient safety is the accurate assessment and minimization of risk for human immunodeficiency virus (HIV), Hepatitis C (HCV), and Hepatitis B (HBV) virus transmission by deceased donor organ and tissue transplantation. The pathogens are tested by serological kits based on enzyme-linked immunosorbent assay (ELISA), chemiluminescence (CLIA) and eletrochemiluminescence (ECLIA) immunoassays. Organ transplantation is a highly successful life-saving treatment in Brazil, but the Brazilian Health Surveillance Agency currently mandates that all deceased organ donors are screened for HIV, HCV and HBV following living donor policies. In this review, six ELISA (Wama^®, Bio-Rad^®, Biomerieux^®, DiaSorin^®, Acon Biotech^® and Biokit^®), three CLIA (Abbott^®, Siemens^®, Diasorin^®) and one ECLIA (Roche^®) were utilized for evaluating the effectiveness of those serological tests for deceased donors in Brazil according to manufacturer's guidelines. NAT for HIV, HCV and HBV can assist with detection of pre-seroconversion for those infections, and only Cobas^® TaqScreen MPX^® test, the Tigris System^® Procleix Ultrio Assay^® and the Bio-Manguinhos^® HIV/HCV/HBV NAT are commercially available. Between all the tests, only the manufacturer Abbott^® and Cobas^® TaqScreen MPX^® test are currently validated for cadaver samples.