Risk of SARS-CoV-2 Transmission via Corneal Transplant From Donors With COVID-19

Tracing the SARS-CoV-2 infection on the ocular surface: Overview and preliminary corneoscleral transcriptome sequencing

COVID-19's impact on the ocular surface has already been recognized, however the molecular mechanisms induced by the infection on the ocular surface are still unclear. The aim of this paper is to provide a first overview of the transcriptional perturbations caused by SARS-CoV-2 on the ocular surface by analyzing gene expression profile of corneoscleral ring samples from post-mortem SARS-CoV-2 positive donors (PD). The presence of SARS-CoV-2 on the ocular surface, in tears and corneal tissues has rarely been detected in infected individuals in both the presence and the absence of ocular manifestations. In this preliminary study, 6 human corneoscleral tissues of 3 PD and two tissues from a negative donor (CTRL) were obtained at the local eye bank. The presence of genomic and sub-genomic SARS-CoV-2 RNAs was assessed by qRT-PCR, while transcriptome analysis (RNA-sequencing) was performed by Illumina. Principal Component Analysis (PCA), search for differentially expressed genes (DEGs) and Gene Ontology (GO)-enrichment analysis were performed. Three samples from PD were found positive for SARS-CoV-2 genomic RNA, although the absence of sub-genomic RNAs indicated an inactive virus. PCA analysis grouped 3 different clusters, one including CTRL, and the other two including, respectively, PD with undetected SARS-CoV-2 (PD-SARS-neg) and PD with detected SARS-CoV-2 (PD-SARS-pos). The DEGs in common with the 2 PD clusters included several genes associable to the interferon pathway, such as ADAMTS4, RSAD2, MMP1, IL6, ISG15 and proinflammatory cytokines. Among the down-regulated genes we found AQP5. GO analysis revealed 77 GO terms over-represented in PD-SARS-neg vs. CTRL, and 17 GO terms in PD-SARS-pos vs. CTRL. The presence of SARS-CoV-2 RNA and RNA-sequencing reads in ocular surface tissues supports the possibility that the eye acts as an entry route. The modulation of early responsive genes, together with several ISGs suggests a potential protective responsiveness of the ocular tissues to SARS-CoV-2.

COVID-19: Update on Its Ocular Involvements, and Complications From Its Treatments and Vaccinations

ABSTRACT

The coronavirus disease 2019 (COVID-19) came under the attention of the international medical community when China first notified the World Health Organization of a pneumonia outbreak of then-unknown etiology in Wuhan in December 2019. Since then, COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has appalled the world by spreading at a pandemic speed. Although ophthalmologists do not directly engage in the clinical care of COVID-19 patients, the ophthalmology community has become aware of the close ties between its practice and the pandemic. Not only are ophthalmologists at heightened risk of SARS-CoV-2 exposure due to their physical proximity with patients in routine ophthalmic examinations, but SARS-CoV-2 possesses ocular tropism resulting in ocular complications beyond the respiratory tract after viral exposure. Furthermore, patients could potentially suffer from adverse ocular effects in the therapeutic process. This review summarized the latest literature to cover the ophthalmic manifestations, effects of treatments, and vaccinations on the eye to aid the frontline clinicians in providing effective ophthalmic care to COVID-19 patients as the pandemic continues to evolve.