Profile of Eye-Related Emergency Department Visits in Ontario – A Canadian Perspective (preprint)

Background: Understanding the epidemiology of ophthalmic presentations to emergency departments can help guide resource allocation, medical education programs, and optimize the patient experience. The purpose of this investigation was to summarize and assess the urgency of ophthalmic presentations in emergency departments (EDs) in Ontario, Canada over a 5-year period.  Methods: This was a multicentered retrospective review of all patient presentations to EDs in Ontario between January 1st, 2012, to December 31st, 2017. Presentations were included if patients had an ophthalmic related ICD-10 code as their primary problem prompting ED presentation. Patients under the age of 18 were excluded from this investigation. Results: A total of 774,057 patients patient presentations were included across the pediatric (149,679 patients) and adult (624,378 patients) cohorts. The mean (SD) age at presentation was 47.4 (17.9) years, and 6.54 (5.20) in the adult and pediatric cohorts respectively. Of the total presentations, 256,776 (33.1%) were due to a trauma related presentation. Problems pertaining to Cornea and External disease were the most common reason for presentation (51.0% of cases). Of all presentations, 34.1% were classified as either ‘emergent’ or ‘likely emergent’; the remaining presentations were either ‘non-emergent’ (39.5%) or the urgency ‘could not be determined’ (26.4%). The three most frequent presentations were due to conjunctivitis (121,175 cases or 15.7%), ocular foreign bodies (104,322 cases or 13.5%), and corneal / conjunctival abrasions (94,554 cases of 12.2%). Conclusions: This investigation summarizes all ophthalmic presentations to EDs in Ontario, Canada over a 5-year period. The results of this investigation can help guide ophthalmic related knowledge translation. Additionally, these results highlight that in Canadian EDs, a significant proportion of ophthalmic presentations are nonurgent; systems level efforts to improve access for eye-related complaints to healthcare professionals outside of the ED can help facilitate improved resource allocation. As we emerge from the COVID-19 pandemic, optimising the structure of patient care access is crucial to help alleviate the pressure from overburdened EDs while effectively meeting patient healthcare needs.

Collateral damage: Corneal injury due to mask use during the COVID-19 pandemic - A case series.

Though masks are the best shield against COVID-19, they can be a source of discomfort and ocular side effects. We discuss three cases of corneal injury due to mask use. Three patients, who were healthcare workers, presented with discomfort, photophobia, and pain in the eyes. While adjusting the mask, they had an ocular injury. There were multiple superficial linear abrasions in the eyes. They recovered with treatment. Though masks are imperative during the COVID-19 pandemic, it is important to be aware of a possible mask injury.

ELV-N32 and RvD6 isomer decrease pro-inflammatory cytokines, senescence programming, ACE2 and SARS-CoV-2-spike protein RBD binding in injured cornea.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that causes coronavirus disease 2019 (COVID-19) has resulted in a pandemic affecting the most vulnerable in society, triggering a public health crisis and economic collapse around the world. Effective treatments to mitigate this viral infection are needed. Since the eye is a route of virus entrance, we use an in vivo rat model of corneal inflammation as well as human corneal epithelial cells (HCEC) in culture challenged with IFNγ as models of the eye surface to study this issue. We explore ways to block the receptor-binding domain (RBD) of SARS-CoV-2 Spike (S) protein to angiotensin-converting enzyme 2 (ACE2). We found that the lipid mediators, elovanoid (ELV)-N32 or Resolvin D6-isomer (RvD6i) decreased the expression of the ACE2 receptor, furin, and integrins in damaged corneas or IFNγ-stimulated HCEC. There was also a concomitant decrease in the binding of Spike RBD with the lipid treatments. Using RNA-seq analysis, we uncovered that the lipid mediators also attenuated the expression of pro-inflammatoy cytokines participating in hyper-inflammation and senescence programming. Thus, the bioactivity of these lipid mediators will contribute to open therapeutic avenues to counteract virus attachment and entrance to the body.

Co-expression of Mitochondrial Genes and ACE2 in Cornea Involved in COVID-19 Infection (preprint)

The Coronavirus disease 2019 (COVID-19) pandemic severely challenges public health and necessitates the need for increasing our understanding of COVID-19 pathogenesis, especially host factors facilitating virus infection and propagation. Here, the co-expression network was constructed by mapping the well-known ACE2, TMPRSS2 and host susceptibility genes implicated in COVID-19 GWAS onto a cornea, retinal pigment epithelium and lung. We found a significant co-expression module of these genes in the cornea, revealing that cornea is potential extra-respiratory entry portal of SARS-CoV-2. Strikingly, both co-expression and interaction networks show a significant enrichment in mitochondrial function, which are the hub of cellular oxidative homeostasis, inflammation and innate immune response. We identified a corneal mitochondrial susceptibility module (CMSM) of 14 mitochondrial genes by integrating ACE2 co-expression cluster and SARS-CoV-2 interactome. Gene ECSIT, as a cytosolic adaptor protein involved in inflammatory responses, exhibits the strongest correlation with ACE2 in CMSM, which has shown to be an important risk factor for SARS-CoV-2 infection and prognosis. Our co-expression and protein interaction network analysis uncover that the mitochondrial function related genes in cornea contribute to the dissection of COVID-19 susceptibility and potential therapeutic interventions.

Eye care in the intensive care unit during the COVID-19 pandemic.

Ocular complications in critical care patients are common. There has been a surge in intensive care admissions following the COVID-19 outbreak. The management of COVID-19 exposes patients to a number of specific risk factors for developing ocular complications, which include non-invasive ventilation, mechanical ventilation and prone positioning. Consequently, it is likely that there will be an increase in the number of ocular complications secondary to the management of COVID-19 patients in the intensive care unit setting, and these complications could lead to permanent visual loss and blindness. Increased awareness of eye care in the intensive care unit setting is therefore vital to help prevent visual loss and maintain quality of life for patients recovering from COVID-19.

ACE2 and TMPRSS2 are expressed on the human ocular surface, suggesting susceptibility to SARS-CoV-2 infection (preprint)

Purpose Conjunctival signs and symptoms are observed in a subset of patients with COVID-19, and SARS-CoV-2 has been detected in tears, raising concerns regarding the eye both as a portal of entry and carrier of the virus. The purpose of this study was to determine whether ocular surface cells possess the key factors required for cellular susceptibility to SARS-CoV-2 entry/infection.Methods We analyzed human post-mortem eyes as well as surgical specimens for the expression of ACE2 (the receptor for SARS-CoV-2) and TMPRSS2, a cell surface-associated protease that facilitates viral entry following binding of the viral spike protein to ACE2.Results Across all eye specimens, immunohistochemical analysis revealed expression of ACE2 in the conjunctiva, limbus, and cornea, with especially prominent staining in the superficial conjunctival and corneal epithelial surface. Surgical conjunctival specimens also showed expression of ACE2 in the conjunctival epithelium, especially prominent in the superficial epithelium, as well as the substantia propria. All eye and conjunctival specimens also expressed TMPRSS2. Finally, western blot analysis of protein lysates from human corneal epithelium obtained during refractive surgery confirmed expression of ACE2 and TMPRSS2.Conclusions Together, these results indicate that ocular surface cells including conjunctiva are susceptible to infection by SARS-CoV-2, and could therefore serve as a portal of entry as well as a reservoir for person-to-person transmission of this virus. This highlights the importance of safety practices including face masks and ocular contact precautions in preventing the spread of COVID-19 disease.Competing Interest StatementThe authors have declared no competing interest.View Full Text