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PURPOSE: The purpose of this study was to report the analysis of reverse transcriptase polymerase chain reaction (RT-PCR) of nasopharyngeal (NP) samples of cornea donors dying because of causes unrelated to severe acute respiratory coronavirus (SARS-CoV-2). METHODS: A retrospective analysis of all cornea donors dying from causes other than SARS-CoV-2 between August 2020 and December 2020 was performed. Informed consent was obtained from the next of kin of the deceased for RT-PCR testing from NP swabs. Rapid antigen testing from all the deceased was performed before in situ cornea excision. In addition, NP samples in viral transport media for RT-PCR were also collected for SARS-CoV-2 analysis. Corneas were released from the eye bank only after a negative RT-PCR report. RESULT: One hundred eighteen corneas from 59 donors were obtained by the eye bank. Eleven donors (18.64%) were positive for SARS-CoV-2 on RT-PCR testing. Six of these 11 donors had a Ct value of E gene less than 25. CONCLUSIONS: NP samples of cornea donors dying due to causes other than coronavirus disease-19 were positive for SARS-CoV-2 on RT-PCR. This implicates that donors could be having asymptomatic/undetected coronavirus disease infection. We recommend adding the routine testing of NP samples of all cornea donors in the eye banking protocol in this ongoing SARS-CoV-2 pandemic.

The recent outbreak of coronavirus disease 2019 (COVID-19) has been declared a public health emergency worldwide. The scientific community has put in much effort and published studies that described COVID-19’s biology, transmission, clinical diagnosis, candidate therapeutics, and vaccines. However, to date, only a few data are available on the impact of COVID-19 pandemic on ophthalmological care in different health care systems, its future consequences in terms of disability, and access to sight-saving cures for many patients. To reduce human-to-human transmission of the virus and also ensure supply of infrastructures, human resources, and disposable medical devices to many regions, it is crucial to assess risks and postpone non-essential outpatient visits and elective surgical procedures, especially in older patients and those with comorbidities. This delay or suspension in essential eye procedures may cause significant and rapid vision impairment to irreversible blindness. Determining the risk-benefit profile of treating these ocular pathologies is a public health issue of supreme priority, even though many patients benefiting from therapeutic treatments are elderly, who are more vulnerable to COVID-19. If not reversible, this process could lead to a dramatic increase in disability and unsustainable social costs for many Governments.

Even though the cornea is regarded as an immune-privileged tissue, transplantation always comes with the risk of rejection due to mismatches between donor and recipient. It is common sense that an alternative to corticosteroids as the current gold standard for treatment of corneal transplantation is needed. Since blood and lymphatic vessels have been identified as a severe risk factor for corneal allograft survival, much research has focused on vessel regression or inhibition of hem- and lymphangiogenesis in general. However, lymphatic vessels have been identified as required for the inflammation’s resolution. Therefore, targeting other players of corneal engraftment could reveal new therapeutic strategies. The establishment of a tolerogenic microenvironment at the graft site would leave the recipient with the ability to manage pathogenic conditions independent from transplantation. Dendritic cells (DCs) as the central player of the immune system represent a target that allows the induction of tolerogenic mechanisms by many different strategies. These strategies are reviewed in this article with regard to their success in corneal transplantation.

Introduction Recipients of corneal transplants are at risk of healthcare-associated infections, which, apart from other causes of surgical site infections, may also occur as a result of the transfer of infected corneal tissue. In this study we assessed the risk of bacterial and fungal infections based on the results of routine microbiological testing of cornea preservation fluid samples. Material and methods We examined a total of 725 samples of corneal preservation fluid, obtained during a period of 3 years (2011-2013). Corneal preservation fluid samples were cultured and identified in accordance with standard microbiological methods. Results The analysis comprised 725 samples of corneal preservation fluid, of which 32 (4.4%) samples tested positively in microbiological cultures. In total, 34 strains of bacteria and fungi were cultured. Gram-positive bacteria, Gram-negative bacteria and fungi comprised 85.3%, 8.8% and 5.9% of these strains, respectively. Analysis of the susceptibility of the cultured bacterial isolates to gentamicin was also performed, as this antibiotic is present in the composition of corneal preservation fluid. Among the cultured bacterial strains, 10 (33.3%) were resistant to gentamicin. None of the 32 patients who received a cornea stored in preservation fluid contaminated with bacteria and/or fungi demonstrated infectious complications in the surgical site within 1 year following cornea transplantation. Conclusions We postulate that perioperative antibiotic prophylaxis in cornea transplant recipients is important in preventing bacterial infections derived from the donor cornea. We believe that the addition of an antifungal agent to commercially available cornea preservation fluids should also be considered.

Under normal conditions, the cornea, being the transparent “windscreen” of the eye, is free of both blood and lymphatic vessels. However, various diseases of the eye, like infections, can interfere with the balance between promoting and inhibiting factors, which leads to ingrowth of blood and lymphatic vessels. The newly formed lymphatic vessels increase the risk of graft rejection after subsequent corneal transplantation. Corneal transplantation is one of the most commonly performed transplantations worldwide, with more than 40,000 surgeries per year in Europe. To date, various anti-hem- and anti-lymphangiogenic treatment strategies have been developed specifically for the corneal vascular endothelial growth factor (VEGF) pathway. Currently, however, no treatment strategies are clinically available to specifically modulate lymphangiogenesis. In this review, we will give an overview about endogenous regulators of hem- and lymphangiogenesis and discuss potential new strategies for targeting pathological lymphangiogenesis. Furthermore, we will review recently identified modulators and demonstrate that the cornea is a suitable model for the identification of novel endogenous modulators of lymphangiogenesis. The identification of novel modulators of lymphangiogenesis and a better understanding of the signaling pathways involved will contribute to the development of new therapeutic targets for the treatment of pathological lymphangiogenesis. This, in turn, will improve graft rejection, not only for the cornea.

Objective This study investigated an alternative approach for obtaining donor corneas for keratoplasty that can be used in nations with high corneal demand and high costs for treatment of non-healing ulcers or lesions. Methods Eighteen patients (18 eyes) who underwent tectonic keratoplasty using small incision refractive lenticule extraction (SMILE)-extracted lenticule were included. Data were recorded regarding age, corneal status, corneal lesion location and size, preoperative and postoperative visual acuity, lenticule layer, and additional medical history. Results Corneal thinning and corneal perforation in 13 and 5 patients, respectively, were treated with tectonic keratoplasty using SMILE-extracted lenticule. After tectonic keratoplasty, globe integrity was maintained in 16 of the 18 patients. The mean decimal visual acuity improved from 0.2555±0.3326 preoperatively to 0.3303±0.3487 at the final follow-up. Visual acuity improvement was greater in patients with corneal perforation than in patients with corneal thinning. In addition, visual acuity was most improved in patients with infratemporal lesions. Conclusion Tectonic keratoplasty using SMILE-extracted lenticule is a comparatively safe, effective, and reliable alternative approach for the treatment of corneal lesions.

PURPOSE: Acanthamoeba (AA) keratitis is a rare and severe infection with poor prognosis. The aim was to investigate the incidence and risk factors of AA keratitis in a large tertiary ophthalmology department in Denmark.METHODS: A search was performed in our electronic patient records by the keywords: 'PHMB/polyhexanid', 'Brolene' or 'amoeba and chlorhexidine' from year 1994 to 2018, and afterwards medical records were reviewed. A total of 65 cases of AA keratitis were hereby identified.RESULTS: Patients were relatively young, median (range) age of 38 (15-70) years. A significant increase of diagnosing AA keratitis occurred from 0.13 cases per million per year in the first 5 years to 2.7 cases per million per year the last 5 years. Eighty-nine per cent of patients were contact lens users, and 49% had received corticosteroids before the diagnosis was established. Severe pain was present in 34% of patients. Prognosis was poor with final visual acuity of logMAR (mean, 95% CI) 0.30 (0.18-0.41), 18% had transplantation à chaud, and 2% were enucleated.CONCLUSION: The study indicates that the incidence of AA keratitis is increasing, also in Denmark. Most patients were young contact lens users. The course of the disease is long and often painful, and the prognosis is poor despite relevant treatment.

Objective of the work is to investigate stress and deformation that conrneal tissue and donor graft undergo during endothelial keratoplasty. In order to attach the donor graft to the cornea, different air bubble pressure profiles acting on the graft are considered. This study is carried out by employing a three-dimensional nonlinear finite element methodology, combined with a contact algorithm. The ocular tissues are treated as isotropic, hyper-elastic and nearly-incompressible materials. The contact algorithm, based on the penalty-based node-to-surface approach, is used to model the donor graft-corneal interface region. First, the proposed computational methodology is tested against benchmark data for bending of the plates over a cylinder. Then, the influence of geometrical and material parameters of the graft on the corneal contact-structural response is investigated. The results are presented in terms of Von Mises stress intensity, displacement and mean contact force. Results clearly indicate that the air bubble pressure plays a key role in the corneal stress and strain, as well as graft stiffness and thickness.

High-risk cornea transplant recipients represent a patient population with significant un-met medical need for more effective therapies to prevent immunological graft rejection due to heightened anti-donor immune response. In this study, a rat model of pre-existing anti-donor immunity was developed in which corneal allografts were rejected earlier than in non-pre-sensitized recipients. In this model, third-party (non-donor, non-recipient strain) allogeneic mesenchymal stromal cells (allo-MSC) were administered intravenously 7 and 1 days prior to transplantation. Rejection-free graft survival to 30 days post-transplant improved from 0 to 63.6% in MSC-treated compared to vehicle-treated control animals (p = < 0.0001). Pre-sensitized animals that received third-party allo-MSC prior to transplantation had significantly higher proportions of CD45+CD11b+ B220+ monocytes in the lungs 24 h after the second MSC injection and significantly higher proportions of CD4+ FoxP3+ regulatory T cells in the graft-draining lymph nodes at the average day of rejection of control animals. In in vitro experiments, third-party allo-MSC polarized primary lung-derived CD11b/c+ myeloid cells to a more anti-inflammatory phenotype, as determined by cytokine profile and conferred them with the capacity to suppress T cell activation via prostaglandin E2 and TGFβ1. In experiments designed to further validate the clinical potential of the protocol, thawed cryopreserved, third-party allo-MSC were shown to be similarly potent at prolonging rejection-free corneal allograft survival as their freshly-cultured counterparts in the pre-sensitized high-risk model. Furthermore, thawed cryopreserved third-party allo-MSC could be co-administered with mycophenolate mofetil without adversely affecting their immunomodulatory function. In conclusion, a clinically-relevant protocol consisting of two intravenous infusions of third-party allo-MSC during the week prior to transplantation, exerts a potent anti-rejection effect in a pre-sensitized rat model of high-risk corneal allo-transplantation. This immune regulatory effect is likely to be mediated in the immediate post-transplant period through the promotion, by allo-MSC, of alternatively-activated macrophages in the lung and, later, by enhanced regulatory T-cell numbers.

Background: Our aim was to demonstrate the publication trends of corneal transplantation in the last decade. Methods: All of the keratoplasty research articles, letters, case reports, reviews and meeting abstracts published between January 2006 and December 2015 indexed on the Thomson Reuters Web of Knowledge were evaluated. A bibliometric filter was used to capture keratoplasty related publications by using the key words 'keratoplasty', 'corneal transplantation' or 'keratoprosthesis' in the 'title' selection mode. Results: A total of 2726 publications were evaluated in the present study. Documents related to penetrating keratoplasty only have been decreased, whereas the documents related to endothelial keratoplasty were increased in the last decade. The total keratoplasty publication counts had been increased from the year 2006 to 2015. The average citation count per keratoplasty documents was 9.34. Conclusions: There is a growing interest to the lamellar keratoplasty techniques especially the endothelial keratoplasty in the last decade. © 2016 The Author(s).

OBJETIVOS: Quantificar e qualificar a microbiota aeróbia da conjuntiva de doadores de córnea segundo a interferência do intervalo de tempo entre o óbito e a colheita do espécime conjuntival, a causa do óbito e a idade do doador e avaliar a atividade biocida de determinados antibióticos aos microrganismos isolados. MÉTODOS: Entre janeiro e março de 1994 foram colhidos espécimes da conjuntiva de 242 olhos de doadores de córnea. O material transportado em meio de Stuart foi semeado em ágares sangue, chocolate, sangue azida, MacConkey e caldo tioglicolato. Foi registrada a idade do doador, hora e causa do óbito. A atividade biocida dos antibióticos foi avaliada pela metodologia de Kirby e Bauer. A análise estatística utilizou os testes do qui-quadrado, exato de Fisher e Mann-Whitney. RESULTADOS: A freqüência de cultura positiva da conjuntiva de doadores de córnea foi de 91,7%. A mediana da idade dos doadores foi de 62 anos e do intervalo de tempo entre o óbito e a colheita do espécime foi de 4,2 horas. A causa mais freqüente de óbito foi doença cardiovascular (26,4%). Não houve diferença significante entre a cultura positiva e as variáveis estudadas. A vancomicina inibiu 100% das cepas de bactérias Gram-positivas e a sensibilidade dos bacilos Gram-negativos à gentamicina variou de 36,7% a 92,3%. CONCLUSÕES: O estudo revelou freqüência elevada de cultura positiva da conjuntiva de doadores de córneas. Staphylococcus coagulase negativo foi a espécie com maior número de isolamentos positivos. Não foi encontrada associação entre os fatores de risco avaliados e cultura positiva. Os antibióticos tiveram atividade biocida variável sobre os Gram-negativos e 100% dos Gram-positivos foram sensíveis à vancomicina. PURPOSE: To identify and qualify bacterial organisms in conjunctival tissue of donor corneas. To correlate the frequency of positive cultures with donor age, cause of death, and time from death to collection of conjunctival samples. To investigate bacterial susceptibility to specific antibiotics. METHODS: Conjunctival samples obtained from the inferior conjunctival fornix of 242 eyes of cornea donors were collected between January and March, 1994. The samples were transferred to Stuart´s medium and then inoculated into blood, acid blood, chocolate, McConkey agars, and thioglycolate broth. Donor age, time and cause of death were recorded. Bacterial susceptibility to antibiotics was tested using the diffusion method on agar modified by Kirby and Bauer. Statistical analysis was done using the chi-square, Fisher's exact and Mann-Whitney tests. RESULTS: Microorganisms were identified in 91.7% of the samples. The most frequently isolated microorganism was coagulase-negative Staphylococcus (27.3%). Time from death to collection of the conjunctival sample was on the average 4.2 hours. The most frequent cause of death was cardiovascular disease (26.4%). The median donor age was 62 years. No significant correlation between positive cultures and the investigated variables was found. Vancomycin inhibited bacterial growth in 100% of Gram-positive microorganisms. The sensitivity of Gram-negative bacteria to gentamicin ranged from 36.7 to 92.3%. CONCLUSION: The frequency of positive conjunctival cultures of donor corneas was 91.7%. No significant statistical difference was found between positive cultures and the investigated parameters. Vancomycin inhibited the growth of Gram-positive bacteria in 100% of the cases and the sensitivity of Gram-negative bacteria to gentamicin varied.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:22:30Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:40:25Z : No. of bitstreams: 1 2-s2.0-37349020069.pdf: 220699 bytes, checksum: 56cde780e5c745f05dddd4c0b6ca17a1 (MD5) Made available in DSpace on 2014-05-27T11:22:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-07-01 Purpose: To compare knowledge of medical students about the cornea donation process among those who already studied Ophthalmology and the others. Methods: A questionnaire containing data as: age, sex, graduation year, and 10 multiple-choice questions about the subject was applied to medical students from the interior of São Paulo state, Brazil. The questions were: age for donation, contraindication for transplants, the time limit to remove the cornea, among others. The knowledge regarding cornea donation was compared between the two groups: students who already studied Ophthalmology (Group A) and the others (Group B). Results: The study group was composed of 402 students, of whom 140 were of group A and 262 of group B. Knowledge between the two groups was different, but not statistically significant (p=0.8328). Conclusion: Knowledge about the cornea donation process among the interviewed seemed to be insufficient, even those who had studied Ophthalmology. Information and education about transplants in Medical Schools should be improved. Departamento de Oftalmologia Otorrinolaringologia e Cabeça e Pescoço Faculdade de Medicina de Botucatu Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, Botucatu, SP Faculdade de Ciências Médicas de Sorocaba Pontifícia Universidade Católica de São Paulo -PUCSP, Sorocaba, SP Departamento de Medicina Faculdade de Ciências Médicas de Sorocaba PUCSP, Sorocaba, SP Departamento de Oftalmologia Faculdade de Ciências Médicas de Sorocaba PUCSP, Sorocaba, SP , Alameda dos Jerivás, 166, Itu, SP 13301-635 Departamento de Oftalmologia Otorrinolaringologia e Cabeça e Pescoço Faculdade de Medicina de Botucatu Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, Botucatu, SP

Background Lymphangiogenesis is one of the major causes of corneal graft rejection. Among the lymphangiogenic factors, vascular endothelial growth factor (VEGF)-C and -D are considered to be the most potent. Both bind to VEGF receptor 3 (VEGFR3) to activate Prospero homeobox 1 (Prox1), a transcription factor essential for the development and maintenance of lymphatic vasculature. MicroRNAs (miRNAs) bind to the 3' untranslated regions (3' UTRs) of target genes in a sequence-specific manner and suppress gene expression. In the current study, we searched for miRNAs that target the pro-lymphangiogenic factor Prox1. Results Among the miRNAs predicted by the bioinformatic analysis to seed match with the 3' UTR of Prox-1, we chose 3 (miR-466, miR-4305, and miR-4795-5p) for further investigation. Both the miR-466 and miR-4305 mimics, but not the miR-4795-5p mimic, significantly reduced the luciferase activity of the Prox-1 3' UTR reporter vector. In primary lymphatic endothelial cells (HDLEC), miR-466 mimic transfection suppressed Prox1 mRNA and protein expression, while miR-4305 mimic transfection did not. Experiments using mutated reporter constructs of the two possible seed match sites on the 3' UTR of Prox1 suggested that the target site 2 directly bound miR-466. HDLEC transfected with the miR-466 mimic suppressed tube formation as compared to the scrambled control. Furthermore, HDLEC transfected with a miR-466 inhibitor showed enhanced tube formation as compared to control inhibitor transfected cells, and this inhibitory effect was counteracted by Prox1 siRNA. The miR-466 mimic reduced angiogenesis and lymphangiogenesis resulting in clearer corneas in an cornea injury rat model compared to the scrambled control. Conclusions Our data suggest that miR-446 may have a protective effect on transplanted corneas by suppressing Prox1 expression at the post-transcriptional level. The results of the current study may provide insights into the mechanisms of lymphangiogenesis resulting from corneal graft rejection and alkali-burn injuries, as well as into the development of new treatments for lymphangiogenic eye diseases. Electronic supplementary material The online version of this article (doi:10.1186/s12929-014-0104-0) contains supplementary material, which is available to authorized users.