Impact of the COVID-19 Pandemic on Corneal Transplantation: A Report From the Italian Association of Eye Banks

Purpose: To analyze the impact of COVID-19 on Italian corneal transplantation from March-2020 to February 2021 compared to the same timeframe of the 2 previous years, in order to identify potential consequences of a global pandemic on corneal procurement and transplantation services during this time. Methods: This national, multicentric, retrospective cohort study evaluated data collected from 12 (100%) Italian eye banks from March 2020 to February 2021 (Group A). The number of tissues collected, distributed and discarded were compared with the same time-frame of the 2 previous years: 2019 and 2018 (group B and C, respectively). The different type of transplants performed were reported. Data were analyzed using a non-parametric Friedman test. Results: Corneal procurement and the percentage of distributed tissues reduced in 2020 by more than 30 and 15%, respectively, compared to the 2 previous years. During the pandemic corneal transplant surgery showed only a modest drop: the number of the penetrating keratoplasties (PKs) and the anterior lamellar keratoplasties (ALKs) decreased by about 30 and 20% in comparison with groups B and C, respectively; between the Endothelial Keratoplasties (EKs), the Descemet membrane endothelial keratoplasty (DMEK) increased slightly from March 2020 to February 2021. Conclusions: Italy was one of the first countries most affected by the outbreak of COVID-19, and the Italian government adopted severe measures to limit viral transmission. The pandemic generated several implications in corneal transplant activity during the first lockdown. Then an efficacious reaction with constant, vigorous work led to a resumption of transplant surgery to a near-normal standard. The increase of EKs, despite the pandemic, is a sign that the advance in corneal transplantation has gone ahead and it continues to evolve

Corneal transplant during COVID-19 pandemic: the Italian Eye Bank national report

To investigate the impact of Coronavirus Disease-2019 lockdown on the Italian Eye Bank organization. In this national retrospective, multicentric, cohort study, data from the Italian Eye Bank during both the lockdown and the first month after the lockdown period were retrieved. We compared the Italian Eye Bank metrics with the same timeframe of 2019 and 2018. Data from 13 out of 13 (100%) Italian Eye Banks were included in the analysis. A statistically significant reduction in the number of donor corneas retrieved in 2020 was found as compared to the same period in 2019 and in 2018, respectively (2020 = 1284; 2019 = 3088; 2018 = 3221; ANOVA: p < 0.0001). Only 534 corneas have been distributed by Eye Banks during the COVID-19-lockdown period (2020 = 534; 2019 = 1220; 2018 = 1237. ANOVA: p < 0.0001). Similarly, the number of wasted corneas due to postponed or cancelled surgeries was 421, resulting in a considerable increase as compared to the previous 2 years (2020 = 421; 2019 = 67; 2018 = 84; ANOVA: p = 0.0035). Overall, 45 donor corneas were rejected in accordance with the guidance of the Italian National Health Institute Italian National Transplant Centre (CNT). SARS-CoV-2 pandemic has profoundly affected every social and medical field, including the Eye Bank procurement and distribution programs. The current data collected from all the Italian Eye Banks highlights the present and the forthcoming difficulties that the Eye Bank community is going to experience, as for the ongoing pandemic

CD38 and CD157 Ectoenzymes Mark Cell Subsets in the Human Corneal Limbus

Nicotinamide adenine dinucleotide (NAD+), a precursor of molecules involved in cell regulatory processes, is released in extra-cellular compartments after stress or inflammation.This study investigates the expression in the human cornea of CD38 and CD157, two NAD+-consuming ectoenzymes and surface receptors. The analysis in corneal epithelial and stromal cells was performed by means of multiple approaches, which included immunofluorescence, reverse transcriptase polymerase chain reaction (RT-PCR), Western blot, and confocal microscopy. The presence of enzymatically active NAD+-consumers in intact corneal cells was analyzed by high performance liquid chromatography (HPLC)-based assays. The results obtained show that CD38 and CD157 are expressed constitutively by corneal cells: CD38 appears as a 45-kDa monomer, while CD157 is a 42- to 45-kDa doublet. The molecules are enzymatically active, with features reminiscent of those observed in human leukocytes. CD38 is expressed by cells of the suprabasal limbal epithelium, whereas it is not detectable in central corneal epithelium and stroma. CD157 is expressed by basal limbal clusters, a p63+/cytokeratin 19+ cell subset reported to contain corneal stem cells, and by stromal cells. The results of the work indicates that the human cornea is equipped with molecular tools capable of consuming extracellular NAD+, and that CD157 is a potential marker of corneal limbal cells in the stem cell niche. The presence and characteristics of these ectoenzymes may be exploited to design drugs for wound repair or for applications in tissue transplantation