The Effect of COVID-19 on Corneal Donor Volumes and Eye Bank Processes: An Analysis From the Eye Bank of Canada (Ontario Division)

Global impact of COVID-19 on corneal donor tissue harvesting and corneal transplantation

Introduction

The purpose of this review is to consolidate and examine the available literature on the coronavirus disease 2019 pandemic and its effect on corneal transplantation and eye banking.

Methods

A primary literature search was conducted using the PubMed (Medline) database with keywords and MeSH terms such as "corneal transplantation," "eye banks," "keratoplasty" and then were combined with COVID-19. Relevant articles through September 2022 were assessed and 25 articles were included in this review.

Results

Donor tissue volumes declined globally during lockdown periods due to a lower number of referrals and tighter tissue screening guidelines. Rates of elective surgeries decreased in the lockdown period compared to respective periods in previous years. However, changes in rates of emergency procedures were not uniform across different regions. Moreover, rates of different elective corneal grafts [i.e., penetrating keratoplasty (PK), endothelial keratoplasty (EK), or anterior lamellar keratoplasty (ALK)] were affected differently with the pattern of change being dependent on region-specific factors.

Conclusion

Both donor tissue volumes and rates of corneal transplant procedures were affected by lockdown restrictions. The underlying etiology of these changes differed by region. Examining the range of impact across many countries as well as the contributing factors involved will provide guidance for future global pandemics.

Prevalence and Predictors of Knowledge and Attitudes Toward Eye Donation Among the General Population: A Systematic Review

PURPOSE

The purpose of this systematic review was to investigate knowledge and attitudes toward eye donation and sources of eye donation information among the general population.

METHODS

A search was conducted using MEDLINE through Ovid and Scopus; CINAHL through EBSCOhost and ProQuest; and Embase through Ovid database entries from January 2010 to March 2021. Quantitative studies were selected if they included participants aged 16 years or older from the general population (nonhealthcare) and had a sample size of >200. Studies were included if they measured knowledge and attitudes toward eye donation and sources of eye donation information. Methodological quality was assessed using JBI criteria, and the data were analyzed using SUMARI software.

RESULTS

A total of 25 studies were included in this review. Pooled data from 6 studies demonstrated that 30.8% of participants [95% confidence interval (CI) = 11.0-55.4] had some knowledge of eye donation. Seventeen studies reported that 40.6% (95% CI = 39.8-41.3) were willing to donate their eyes, and 5 of these studies found that 7.3% (95% CI = 6.5-8.3) had already pledged their eyes. Eleven studies reported on the source of eye donation information, indicating 50.9% of participants (95% CI = 49.8-52.1) received information from mass media.

CONCLUSIONS

The results of this review indicate that understanding eye donation knowledge and attitudes is crucial for developing interventions or tools to increase eye donation rates. Further studies in different populations are required.

Outcomes of keratolimbal allograft from ABO compatible donors for severe bilateral limbal stem cell deficiency

PURPOSE

To report outcomes of keratolimbal allograft (KLAL) compatible for both human leukocyte (HLA) and/or blood type using oral prednisone, mycophenolate, and tacrolimus, with basiliximab if panel reactive antibodies (PRA) are present. Intravenous immunoglobulin (IVIG) was used post-operatively if donor-specific anti-HLA antibodies (DSA) were present.

METHODS

Retrospective interventional series of consecutive patients with KLAL for limbal stem cell deficiency (LSCD) from HLA and/or blood type compatible deceased donors with a minimum follow-up time of 12 months. Main outcome measures were ocular surface stability, visual acuity and systemic immunosuppression (SI) adverse events.

RESULTS

Eight eyes of eight patients with mean age of 48.6 ± 10.1 years (range 34-65 years) were included. Mean follow-up time was 37.3 ± 22.7 months (range 12-71 months) following KLAL; four (50%) had combined LR-CLAL surgery. The etiologies of LSCD were Stevens-Johnson Syndrome (n = 4/8), aniridia (n = 2/8), chemical injury (n = 1/8) and atopic eye disease (n = 1/8). All patients had PRA present and received basiliximab infusions. 5/8 patients received IVIG based on DSA identified pre-operatively. At last follow-up, 7 eyes (87.5%) had a stable ocular surface; 1 eye (12.5%) developed failure and had keratoprosthesis implantation. There was a significant improvement in visual acuity from 1.65 ± 0.48 to 0.68 ± 0.34 logMAR (p = 0.01). SI was tolerated well with minimal adverse events.

CONCLUSIONS

Preliminary outcomes of KLAL with ABO compatible tissue using the Cincinnati protocol, preoperative basiliximab (when PRA present) and post-operative IVIG (when DSA present) are encouraging. This protocol may allow for utilization of deceased donor tissue with results approximating those of living donor tissue transplanted for severe bilateral LSCD.

COVID-19 and Eye Banking: Ongoing Impacts of the Pandemic

PURPOSE

The purpose of this study was to assess the impact of ongoing waves of the COVID-19 pandemic and resulting guidelines on the corneal donor pool with resumption of clinical operations.

METHODS

A retrospective analysis of donors deemed eligible for corneal transplantation at an eye bank from July 1, 2020, through December 31, 2021. Donors ineligible due to meeting Eye Bank Association of America (EBAA) COVID-19 guidelines or a positive postmortem COVID-19 testing were examined. The correlation between COVID-19 rule outs and state COVID positivity was calculated. The number of scheduled surgeries, suitable corneas, imports, and international exports was compared with a pre-COVID period. Postmortem testing was reduced for the final 5 months of the study, and numbers were compared before and after the policy change.

RESULTS

2.85% of referrals to the eye bank were ruled out because of EBAA guidelines. 3.2% of postmortem tests were positive or indeterminate resulting in an ineligible tissue donor (0.42% of referrals). Over the 18-month period, there was a 4.30% shortage of suitable corneas compared with transplantation procedures. There was a significant correlation between postmortem testing and state COVID-19 positivity (r = 0.37, P <0.01), but not with EBAA guidelines (r = 0.19, P = 0.07). When postmortem testing was reduced, significantly more corneas were exported internationally.

CONCLUSIONS

Although corneal transplant procedures were back to normal levels, there was a shortage of suitable corneal tissue. The discontinuation of postmortem testing was associated with a significant increase in international exports of corneal donor tissue.

Effect of Covid-19 on Eye Banks and Corneal Transplantations: Current Perspectives

The coronavirus disease 2019 (COVID-19) pandemic exerted a great impact on medical practice, which was reframed according to the actual needs. Ophthalmological services and procedures including corneal transplantation did not represent an exception. The adoption and implementation of new standard operating procedures as well as of new technologies for remote consultation and smart-working reshaped daily activities of both eye bankers, physicians, researchers, and patients. Regulatory restrictions were issued redefining corneal donor eligibility criteria, as well as handling and harvesting procedures of donor ocular tissues. Surgical schedules underwent an abrupt contraction with prioritization of urgent procedures. Local lockdowns and confinement strategies resulted in both a reduction and redirection of research activities. The evaluation of SARS-CoV-2 colonization of ocular tissues, long-term corneal storage techniques, new disinfection strategies, split corneal transplants and cell-based therapies for the treatment of corneal disease peaked in the pipeline. Aim of this article is to summarizes the overall impact of the pandemic on the corneal transplantation machinery, and the current and future perspectives for the corneal transplant community.