Can the Coronavirus Disease 2019 (COVID-19) Affect the Eyes? A Review of Coronaviruses and Ocular Implications in Humans and Animals

Neurological Involvements of SARS-CoV2 Infection

COVID-19 is a pandemic viral infection caused by a novel coronavirus, SARS-CoV2, which is a global concern of the twenty-first century for its rapid spreading in a short period. Apart from its known acute respiratory involvements, the CNS manifestations of COVID-19 are common. These neurological symptoms are diverse and could range from mild nonspecific or specific symptoms such as the loss of various sensory perceptions, the worrying autoimmune Guillain-Barré syndrome, to the life-threatening acute disseminated encephalomyelitis, and the CNS-mediated respiratory distress. An autopsy report documented the presence of SARS-CoV2 in brain tissues of a COVID-19 patient. However, there is no definite conclusion on the mechanisms of SARS-CoV2 neuroinvasion. These proposed mechanisms include the direct viral invasion, the systemic blood circulation, or the distribution of infected immune cells. Concerning these different neuropathophysiologies, COVID-19 patients who are presenting with either the early-onset, multiple, and severe CNS symptoms or rapid respiratory deterioration should be suspected for the direct viral neuroinvasion, and appropriate management options should be considered. This article reviews the neurological manifestations, the proposed neuroinvasive mechanisms, and the potential neurological sequelae of SARS-CoV2.

Genome composition and genetic characterization of SARS-CoV-2

SARS-CoV-2 is a type of Betacoronaviruses responsible for COVID-19 pandemic disease, with more than 1.745 million fatalities globally as of December-2020. Genetically, it is considered the second largest genome of all RNA viruses with a 5' cap and 3' poly-A tail. Phylogenetic analyses of coronaviruses reveal that SARS-CoV-2 is genetically closely related to the Bat-SARS Like-Corona virus (Bat-SL-Cov) with 96% whole-genome identity. SARS-CoV-2 genome consists of 15 ORFs coded into 29 proteins. At the 5' terminal of the genome, we have ORF1ab and ORF1a, which encode the 1ab and 1a polypeptides that are proteolytically cleaved into 16 different nonstructural proteins (NSPs). The 3' terminal of the genome represents four structural (spike, envelope, matrix, and nucleocapsid) and nine accessory (3a, 3b, 6, 7a, 7b, 8b, 9a, 9b, and orf10) proteins. As the number of COVID-19 patients increases dramatically worldwide, there is an urgent need to find a quick and sensitive diagnostic tool for controlling the outbreak of SARS-CoV-2 in the community. Today, molecular testing methods utilizing viral genetic material (e.g., PCR) represent the crucial diagnostic tool for the SARS-CoV-2 virus despite its low sensitivity in the early stage of viral infection. This review summarizes the genome composition and genetic characterization of the SARS-CoV-2.

Ophthalmic manifestations of COVID-19; a less-appreciated yet significant challenge

AIM

The current world has changed in all shapes since the emergence of the novel coronavirus (nCoV-2) also known as COVID-19. Among the extra-pulmonary manifestations of nCoV-2, ophthalmic symptoms have less been systematically studied. The so far existing body of evidence indicates that nCoV-2 has the potential to affect both anterior and posterior chambers of the eye. Albeit, the exact mechanisms which underlie ophthalmic manifestations of nCoV-2 are yet to be elucidated.

METHODS

The present brief review is an attempt to put together and highlight the significant yet limited number of studies which have spotlighted ophthalmic issues in nCoV-2 patients using a systematic literature search strategy.

RESULTS

All case series or reports (including both published and preprint articles) which described ocular manifestations of patients with COVID-19 and/or documented testing of SARS-COV-2 in ocular secretions via various sampling or detection methods were sought to be included.

CONCLUSION

The ophthalmic presentations in SARS-COV-2 are often found to be salient. Raising awareness in this respect may help defining evidencebased protective measures in today's practice of ophthalmology and allied disciplines.

Potential SARS-CoV-2 main protease inhibitors

The coronavirus disease 2019 (COVID-19) pandemic has prompted an urgent need for new treatment strategies. No target-specific drugs are currently available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but new drug candidates targeting the viral replication cycle are being explored. A prime target of drug-discovery efforts is the SARS-CoV-2 main protease (Mpro). The main proteases of different coronaviruses, including SARS-CoV-2, SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV), share a structurally conserved substrate-binding region that can be exploited to design new protease inhibitors. With the recent reporting of the X-ray crystal structure of the SARS-CoV-2 Mpro, studies to discover Mpro inhibitors using both virtual and in vitro screening are progressing rapidly. This review focusses on the recent developments in the search for small-molecule inhibitors targeting the SARS-CoV-2 Mpro.

Histopathological assessments reveal retinal vascular changes, inflammation and gliosis in patients with lethal COVID-19

PURPOSE

To assess for histopathological changes within the retina and the choroid and determine the long-term sequelae of the SARS-CoV-2 infection.

DESIGN

Comparative analysis of human eyes.

SUBJECTS

Eleven donor eyes from COVID-19 positive donors and similar age-matched donor eyes from patients with a negative test for SARS-CoV-2 were assessed.

METHODS

Globes were evaluated ex-vivo with macroscopic, SLO and OCT imaging. Macula and peripheral regions were processed for epon-embedding and immunocytochemistry.

MAIN OUTCOME MEASURES

Retinal thickness and histopathology, detection of SARS-CoV-2 Spike protein, changes in vascular density, gliosis, and degree of inflammation.

RESULTS

Fundus analysis shows hemorrhagic spots and increased vitreous debris in several of the COVID-19 eyes compared to the control. OCT based measurements indicated an increased trend in retinal thickness in the COVID-19 eyes, however the difference was not statistically significant. Histology of the retina showed presence of hemorrhages and central cystoid degeneration in several of the donors. Whole mount analysis of the retina labeled with markers showed changes in retinal microvasculature, increased inflammation, and gliosis in the COVID-19 eyes compared to the controls. The choroidal vasculature displayed localized changes in density and signs of increased inflammation in the COVID-19 samples.

CONCLUSIONS

In situ analysis of the retinal tissue suggested that there are severe subclinical abnormalities that could be detected in the COVID-19 eyes. This study provides a rationale for evaluating the ocular physiology of patients that have recovered from COVID-19 infections to further understand the long-term effects caused by this virus.

Branch Retinal Vein Occlusion in a COVID-19 Positive Patient

Retinal vein occlusions (RVOs), including central retinal vein occlusions (CRVOs) and branch retinal vein occlusions (BRVOs), are a common cause of morbidity in elderly patients. We present the case of a healthy 74-year-old female patient who initially presented with blurry vision in her left eye in the setting of a symptomatic COVID-19 infection. She was diagnosed with a branch retinal vein occlusion that did not immediately require treatment. Three months later, she again presented with worsening vision and was found to have cystoid macular edema (CME) secondary to the vein occlusion, thus was treated with an intravitreal dexamethasone implant. This case serves to highlight the growing evidence of increased thromboembolic risk associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the possible correlation of COVID-19 infections with ocular pathology, including retinal vein occlusions.

Ophthalmic Screening in Patients with Coronavirus Disease 2019: A Prospective Cohort Study

Postmortem pathological examinations, animal studies, and anecdotal reports suggest that coronavirus disease 2019 (COVID-19) could potentially affect intraocular tissue. However, published evidence is scarce and conflicting. In our study, we screened 100 eyes of 50 patients hospitalized for COVID-19. Relevant medical and ophthalmological history was assessed as well as symptoms, laboratory results, specific treatments, clinical course, and outcome. Ophthalmic exams including assessment of best corrected visual acuity (BCVA), intraocular pressure (IOP), color perception, ocular motility, ophthalmoscopy as well as optical coherence tomography (OCT) of the macula and the optic disc was performed at hospital admission and 29 to 192 days later. Of the 50 patients included, 14 (28%) were female. Median age was 64.5 (range 29–90) years. COVID-19 severity was mild in 15 (30%), severe in 30 (60%), and critical in five cases (10%). At baseline, median BCVA was 0.1 (0–1.8) Logarithm of the Minimum Angle of Resolution (LogMAR) and median IOP was 16 (8–22) mmHg. At follow-up, no relevant changes in BCVA and IOP were documented. No signs of active intraocular inflammation or optic nerve affection were found and OCT findings were widely stable during the observation period. Our findings suggest that COVID-19 does not regularly affect intraocular tissue.

SARS-CoV-2 and the Eye: A Relationship for a Possible Prognostic Tool in COVID-19 Patients

PURPOSE

In December 2019 there was the first report about a new viral infection in Wuhan, China. The new virus was taxonomically designed as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causing the coronavirus disease 2019 (COVID-19). SARS-CoV-2 uses the angiotensin-converting enzyme 2 (ACE2) receptor for cell invasion, which is expressed in different tissues including lungs, small intestine, testicles, kidneys, brain, and the eye. The purpose of this article is to review the available information on the relationship of COVID-19 with the eye, as well as evaluating the possible usefulness of ocular diagnostic tests to help in the diagnosis and/or monitoring of patients with this disease.

METHODS

We performed a retrospective review of relevant articles from November 2019 to April 2020.

RESULTS

Ocular infection by SARS-CoV-2 is still controversial; nevertheless, the possibility of being a viral reservoir has been suggested, increasing the likelihood of infection. Some reports demonstrated the presence of SARS-CoV-2 in tears, and previously published data suggest a pathological increase of cytokine concentrations in COVID-19 patients; the cytokine release syndrome or cytokine storm contributes to lung and central nervous system damage. The usefulness of tears for the measurement of inflammatory cytokines in various diseases is well known, in particular IL-6, which has been correlated to the severity of COVID-19.

CONCLUSION

Considering that the IL-6 signaling cascade may be activated in patients with COVID-19, makes it an excellent target for diagnostic and/or monitoring purposes.

Focused Review: Potential Rare and Atypical Symptoms as Indicator for Targeted COVID-19 Screening

The global pandemic of the coronavirus disease 2019 is a known consequence of infection of severe respiratory syndrome coronavirus-2 (SARS-CoV-2). It has affected nations worldwide with soaring number of cases daily. Symptoms such as fever, cough, and shortness of breath, diarrhea, nausea and vomiting are commonly presented in COVID-19 patients. This focused review aims to discuss these uncommon and atypical COVID-19 symptoms that may be presented which might affect neurological, cardiovascular, cutaneous and ocular systems and their possible mode of actions. Nonetheless, there are some cases of reported uncommon or atypical symptoms which may warrant healthcare professionals to be aware of, especially when in contact with patients. The knowledge and information concerning these symptoms might be able to provide additional cues for healthcare professional by subjecting patients to COVID-19 screening. Meanwhile, it might be able to further enhance the alertness and additional precautions being taken by healthcare personnel, which eventually lead to reduced risk of infections.

Optic Nerve Head Parameters and Peripapillary Retinal Nerve Fiber Layer Thickness in Patients with Coronavirus Disease 2019

Purpose: To quantify the optic nerve head (ONH) and peripapillary retinal nerve fiber layer (pRNFL) thickness in patients with Coronavirus Disease-2019 (COVID-19) and compare the measurements with a healthy control group.Methods: In a comparative cross-sectional observational study, ONH and pRNFL thickness were evaluated in patients with a history of COVID-19, at least 2 weeks after recovery from the systemic disease, and compared with an age-matched, normal control group.Results: Thirty COVID-19 patients along with 60 age- and gender-matched healthy controls were studied. Mean average pRNFL thickness was 105.0 ± 16.3 µm in the COVID-19 patients, compared to 99.0 ± 9.0 µm in the controls (p = .31). The pRNFL thicknesses in all sectors was higher in patients with a history of COVID-19; however, this did not reach statistical significance. Similarly, ONH parameters were not significantly different between the groups.Conclusion: Patients recovered from COVID-19 had unremarkable alterations in the peripapillary RNFL thickness.Abbreviations: ONH: Optic Nerve HeadRNFL: Retinal Nerve Fiber LayerSD-OCT: Spectral-Domain Optical Coherence TomographyCOVID-19: Coronavirus Disease 2019SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus 2CNS: Central Nervous SystemACE: Angiotensin-Converting EnzymeRT-PCR: Reverse Transcription-Polymerase Chain Reaction.

Covid19, beyond just the lungs: A review of multisystemic involvement by Covid19

With the commencement of the COVID19 pandemic, following its 1st case reported in Wuhan in China, the knowledge about the virus as well as the symptoms produced by the disease have drastically increased to this day. The manifestations of COVID19 is now known to affect multiple organ systems of the body, which have shown to have acute as well as chronic complications. Histopathological analysis of the biopsies from the affected organs have implied a direct cytopathic effect of the virus but at the same time not ruling out other causes like hypoxia metabolic changes etc., occurring during the course of the disease. In this review article, we have highlighted the histopathological changes in various organs as reported by various studies throughout the world for a better understanding of the etiopathogenesis of COVID19.

SARS-COV-2 and Ocular Surface: From Physiology to Pathology, a Route to Understand Transmission and Disease

Coronaviruses gained public attention during the severe acute respiratory syndrome (SARS) outbreak in East Asia in 2003 and spread of Middle Eastern respiratory syndrome (MERS) in 2012. Direct human-to-human contact and droplet are the main methods of transmission. Viral stability in aerosols on different surfaces supports evidence on indirect viral acquisition from fomites through the mucous membranes of the mouth, nose, and eyes. Given the pandemic circumstances, the level of evidence in COVID-19 and ophthalmology regarding eye infection, conjunctival transmission, and viral shedding through tears is insufficient. Presently, conjunctival transmission of coronaviruses has not been confirmed and remains controversial. Considering the physiology of the lacrimal system and ocular surface, the eyes are considered an immunoprotective site, with several antiviral molecules and anti-inflammatory proteins. Nevertheless, they represent an interface with the exterior world and face daily putative aggressors. Understanding the host's ocular surface immunological and protective environment is crucial to clarify the potential of the conjunctiva as an entry route for SARS-CoV-2 and as part of this viral infection. We will discuss hypothetical ocular surface transmission mechanisms and related counterarguments addressed to both angiotensin-converting enzyme 2 receptors found on the conjunctival and corneal epithelia and lactoferrin, lysozyme, lipocalin and secretory IgA levels in the tear film. Hopefully, we will promote better understanding of this organ in COVID-19 infection and the potential transmission route that can be helpful in setting recommendations on best practices and protective guidelines to mitigate the disease spread.

COVID-19 and the eye: a review

BACKGROUND

To provide a review for general practitioners and medical specialists about the most common eye complaints and ocular manifestations in a COVID-19 patient.

METHODS

Reviewed 50 articles referenced in 4 databases from 20 December 2019 to 16 September 2020.

RESULTS

Of the 50 articles reviewed, 26 met the criteria for analysis and were included in the study. Among them were 5 reviews, 6 case series, 7 case reports, 4 cross-sectional studies, 2 systematic reviews, 1 cohort study and 1 correspondence. We found that the prevalence of ocular manifestations in patients during the course of COVID-19 varied between 0.8% and 31.6%, depending on the study design. Symptoms of acute conjunctivitis were the most frequent clinical findings. Acute phase reactants were also correlated to ocular manifestations and the severity of the systemic disease in many reports.

CONCLUSIONS

Ocular manifestations are not uncommon in COVID-19 patients and have been associated with higher levels of acute phase reactants as well as a higher degree of severity of the systemic disease. We recommend that all physicians consider COVID-19 as a differential diagnosis in the presence of acute conjunctivitis with or without systemic symptoms.

COVID-2019 Associated with Acquired Monocular Blindness

OBJECTIVE

We documented an older female with Coronavirus(CoV) Disease 2019 (COVID-19) and concomitant acquired monocular blindness. We examined this phenomenon in order to understand COVID-19 better.

METHODS

We observed an older female with COVID-19 and concomitant acquired monocular blindness. The following indicators were monitored during the course of the disease: ocular examinations, flash visual evoked potential examination, a blood test for COVID-19 IgM antibodies, as well as nasopharyngeal swab and tear sample tests for COVID-19 nucleic acid.

RESULTS

The patient's visual acuity for the left eye was NLP and the intraocular pressure was 51 mmHg. Keratic precipitates similar to mutton-fat were spread over the corneal endothelium of the left eye. The funduscopic examination of the patient's left eye revealed severe retinal arterial ischemia, and the color of the retina was off-white. Compared to the right eye, the flash visual evoked potential examination revealed a moderate decrease in P2 wave amplitude for the left eye. A blood test was positive for COVID-19 IgM antibodies, and a nasopharyngeal swab test taken for COVID-19 nucleic acid was positive on May 4, 2020. A sample of the patient's tears was taken, and the nucleic acid test for COVID-19 was still positive two weeks later.

CONCLUSIONS

Our study was the first to find that acute viral retinitis could occur in patients with COVID-19 and severe blindness could be associated with SARS-CoV-2 infection. Therefore, physicians should consider the possibility of coronavirus infection in patients with an abnormal fundus or suddenly vision loss.

Magnetic resonance imaging features of COVID-19-related cranial nerve lesions

The complete features of the neurological complications of coronavirus disease 2019 (COVID-19) still need to be elucidated, including associated cranial nerve involvement. In the present study we describe cranial nerve lesions seen in magnetic resonance imaging (MRI) of six cases of confirmed COVID-19, involving the olfactory bulb, optic nerve, abducens nerve, and facial nerve. Cranial nerve involvement was associated with COVID-19, but whether by direct viral invasion or autoimmunity needs to be clarified. The development of neurological symptoms after initial respiratory symptoms and the absence of the virus in the cerebrospinal fluid (CSF) suggest the possibility of autoimmunity.

Ocular findings in patients with coronavirus disease 2019 (COVID-19) in an outbreak hospital

PURPOSE

The aim of this study was to investigate the ocular findings observed in patients with coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 and to present the relationship between ocular involvement, systemic findings, and laboratory results.

MATERIAL AND METHODS

This cross-sectional study was carried out between 1 May and 30 June 2020. The study included 359 patients diagnosed with COVID-19 and assessed by clinical evaluation, nasopharyngeal polymerase chain reaction, and lung computed tomography.

RESULTS

One hundred ninety-seven (54.9%) of the patients were male and 162 (45.1%) were female. The mean age of the patients was 58.5 years (20-91). Two hundred ninety-four (81.9%) patients were treated in the inpatient clinic and 65 (18.1%) patients were treated in the intensive care unit. Various ocular diseases were observed in 16 (4.5%) of the patients. Although the rate of ocular disease was 12 out of 294 (4.1%) in patients followed up in the inpatient clinic, this rate was 4 out of 65 (6.2%) in intensive care patients. There was no systemic problem in one patient, in whom conjunctival hyperemia was the first and only reason for admission to the hospital. Four patients followed up in the inpatient clinic had conjunctivitis at the time of admission, and conjunctivitis occurred in three patients during hospitalization. Subconjunctival hemorrhage occurred in five patients and vitreous hemorrhage in one patient.

CONCLUSION

Ocular diseases are uncommon in COVID-19 patients but may occur during the first period of the disease or during follow-up. Ocular diseases may be the initial or only sign of COVID-19 infection.

A review on human body fluids for the diagnosis of viral infections: scope for rapid detection of COVID-19

Introduction: The unprecedented outbreaks of corona virus disease of 2019 (COVID-19) have highlighted the necessity of readily available, reliable, precise, and faster techniques for its detection. Nasopharyngeal swab has been the gold standard for the diagnosis of COVID-19. However, it is not an ideal screening procedure for massive screening as it implicates the patient's stay in the hospital or at home until diagnosis, thus causing crowding of the specimen at the diagnostic centers. Present study deal with the exploration of potential application of different body fluids using certain highly objective techniques (Optical and e-Nose) for faster detection of molecular markers thereby diagnosing viral infections.Areas covered: This report presents an evaluation of different body fluids, and their advantages for the rapid detection of COVID-19, coupled with highly sensitive optical techniques for the detection of molecular biomarkers.Expert opinion: Tears, saliva, and breath samples can provide valuable information about viral infections. Our brief review strongly recommends the application of saliva/tears and exhaled breath as clinical samples using technics such as high-performance liquid chromatography-laser-induced fluorescence, photoacoustic spectroscopy, and e-Nose, respectively, for the fast diagnosis of viral infections.

Retinal Vessel Diameter Changes in COVID-19 Infected Patients

Purpose: To evaluate the longitudinal changes in retinal vessel diameters in patients with coronavirus disease 2019 (COVID-19).Methods: This study included 25 patients with COVID-19 (Group 1) and 25 healthy subjects (Group 2). The diameters of peripapillary temporal and nasal retinal arteries and veins were measured at baseline and at 4 months after remission.Results: The baseline diameters of the inferior temporal vein and the artery were increased in group 1 compared to controls (p = .007 and p = .041, respectively). There was also an increase in the diameters of the inferior and superior nasal veins and arteries in group 1 at baseline (p = .001, p = .019, p = .037, and p = .008, respectively). Retinal vessel diameters decreased after remission in all quadrants in comparison to baseline measurements (all p < .05).Conclusion: Increased retinal vessel diameters were measured in COVID-19 patients during the disease. Measurement of retinal vessel diameters may be a noninvasive method of estimating the vascular risk.

Detection of SARS-CoV-2 in Simultaneously Collected Tear and Throat Swab Samples from the Patients with 2019- new SARS-CoV-2 Infection Disease: A Single Center Cross-sectional Study

Objecive: This study aimed to evaluate whether Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can be detected in the tears in the eyes of Coronavirus Disease 2019 (COVID-2019) infected patients and compare the detection consistency of two simultaneously collected samples, from the tears and throat swabs.Methods: A total of 35 COVID-2019 patients were included in this cross-sectional case series study. Throat samples from all enrolled patients were collected with sampling swab, and simultaneously, tear samples were collected with sampling swab from 9 patients (No.1-9) and with Schirmer's strip from the remaining patients (No.10-35) (bilateral eyes for all patients). Sample collecting and testing were performed in three separate time points: first from patients No.1-9, second from patients No.10-29, and third from patients No. 30-35. Reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay was performed.Results: Among enrolled patients, 29 (No.1-29) had mild or moderate clinical symptoms and 6 (No.30-35) had severe symptoms. The mean time interval from the sample collection day to diagnosis confirmation day was 9.71 ± 6.50 days (ranged from 3 to 29 days). None of the patients had conjunctivitis. Nineteen out of 35 (54.3%) throat samples presented positive Rt-PCR results. Three (no.13,21,31) out of 35 (8.6%) tear samples presented positive RT-PCR results. Two (no.21, 31) of these three patients were throat swab positive and one (No. 13) was negative. The consistency analysis indicated that tears and throat samples showed poor consistency (Kappa = -0.009, P = .9).The cycle threshold value (Ct-value) of tear samples collected by sampling swab was significantly higher than that by Schirmer's strip (t = 2.288, P = .03).Conclusion: In spite of the low SARS-CoV-2 positive detection rate of tear samples from COVID-2019 patients, we cannot fully rule out the transmission by ocular surface. Whether tear testing can be used as an aid in judging of SARS-CoV-2 infection need further investigation.

Impact of novel coronavirus infection in patients with uveitis associated with an autoimmune disease: result of the COVID-19-GEAS patient survey

Introducción

El objetivo de este estudio es conocer las características de la COVID-19 en pacientes con uveítis asociada a enfermedades autoinmunes sistémicas (EAS) mediante una encuesta telemática.

Material y métodos

La Sociedad Española de Medicina Interna por medio del Grupo de Trabajo de Enfermedades Autoinmunes realizó una encuesta telemática a pacientes con EAS para conocer las características de la COVID-19 en esta población.

Resultados

Un total de 2.789 pacientes contestaron la encuesta, de los que 28 tenían un diagnóstico de uveítis asociada a una EAS. La mayoría (82%) eran mujeres y caucásicas (82%), con una media de 48 años. Las EAS más frecuentes fueron la enfermedad de Behçet seguida de la sarcoidosis y del lupus eritematoso sistémico. El 46% de los pacientes estaban recibiendo tratamiento con corticoides a una dosis media de prednisona de 11 mg/día. Respecto a la infección, 14 (50%) pacientes referían síntomas compatibles con infección por SARS-CoV-2. Se realizó RT-PCR en el frotis nasofaríngeo en dos pacientes y en uno de ellos (4%) fue positivo.

Conclusiones

Los pacientes con UNI asociada a EAS tanto los asintomáticos como los sintomáticos de COVID-19 habían recibido de forma similar tratamiento inmunosupresor.

Ocular Manifestations of COVID-19: A Systematic Review and Meta-analysis

Several studies have reported the characteristics of Coronavirus disease 2019 (COVID-19), yet there is a gap in our understanding of the ocular manifestations of COVID-19. In this systematic review and meta-analysis, we investigated the prevalence of ocular manifestations in COVID-19 patients. We searched Pubmed, Embase, Scopus, Web of Science, and medRxiv from December 1, 2019 to August 11, 2020. Two independent reviewers screened the articles, abstracted the data, and assessed the quality of included studies in duplicate. Thirty-eight studies were eligible after screening of 895 unique articles, with a total of 8,219 COVID-19 patients (55.3% female; n = 3,486 out of 6,308 patients). Using data extracted from cross-sectional studies, we performed random-effects meta-analyses to estimate the pooled prevalence of ocular symptoms along with 95% confidence interval (CI). The prevalence of ocular manifestations was estimated to be 11.03% (95% CI: 5.71-17.72). In the studies that reported the details of observed ocular symptoms, the most common ocular manifestations were dry eye or foreign body sensation (n = 138, 16%), redness (n = 114, 13.3%), tearing (n = 111, 12.8%), itching (n = 109, 12.6%), eye pain (n = 83, 9.6%) and discharge (n = 76, 8.8%). Moreover, conjunctivitis had the highest rate among reported ocular diseases in COVID-19 patients (79 out of 89, 88.8%). The results suggest that approximately one out of ten COVID-19 patients show at least one ocular symptom. Attention to ocular manifestations, especially conjunctivitis, can increase the sensitivity of COVID-19 detection among patients.

End-to-end SARS-CoV-2 transmission risks in sport: Current evidence and practical recommendations

The coronavirus disease 2019 (COVID-19) pandemic has caused disruption to professional and recreational sports across the world. The SARS-CoV-2 virus can be transmitted by relatively large respiratory droplets that behave ballistically, and exhaled aerosol droplets, which potentially pose a greater risk. This review provides a summary of end-to-end SARS-CoV-2 transmission risk factors for sport and an overview of transmission mechanisms to be considered by all stakeholders. The risk of SARS-CoV-2 transmission is greatest indoors, and primarily influenced by the ventilation of the environment and the close proximity of individuals. The SARS-CoV-2 transmission risks outdoors, e.g. via water, and from fomites, appear less than initially thought. Mitigation strategies include good end-to-end scenario planning of activities to optimise physical distancing, face mask wearing and hygiene practice of individuals, the environment and equipment. The identification and removal of infectious individuals should be undertaken by means of the taking of temperature and COVID-19 symptom screening, and the use of diagnostic monitoring tests to identify asymptomatic individuals. Using adequate video footage, data from proximity technology and subject interviews, the identification and isolation of 'close contacts' should also be undertaken to limit SARS-CoV-2 transmission within sporting environments and into the wider community. Sports should aim to undertake activities outdoors where possible, given the lower SARS-CoV-2 transmission risk, in comparison to indoor environments.

Do Ocular Fluids Represent a Transmission Route of SARS-CoV-2 Infection?

The spread of the new SARS-CoV-2 is marked by a short timeline. In this scenario, explaining or excluding the possible transmission routes is mandatory to contain and manage the spread of the disease in the community. In the recent pandemic, it is still unclear how coronavirus can end up in ocular fluids. Nevertheless, eye redness and irritation in COVID-19 patients have been reported, suggesting that a possible ocular manifestation of SARS-CoV-2 infection may be conjunctivitis. On the basis of epidemiological data provided by previous SARS-Cove infection, numerous theories have been proposed: (1) conjunctiva as the site of direct inoculation by infected droplets; (2) the nasolacrimal duct as a migration route of the virus to the upper respiratory tract, or (3) haematogenic infection of the tear gland. The demand for further investigations to verify ocular involvement in COVID-19 infection came out from the results of recent meta-analysis studies, so the eye cannot be completely excluded as a transmission route of the infection. Thus, healthcare personnel and all the people that enter in contact with infected or suspected patients must always use the prescribed protective equipment.

Product of natural evolution (SARS, MERS, and SARS-CoV-2); deadly diseases, from SARS to SARS-CoV-2

SARS-CoV-2, the virus causing COVID-19, is a single-stranded RNA virus belonging to the order Nidovirales, family Coronaviridae, and subfamily Coronavirinae. SARS-CoV-2 entry to cellsis initiated by the binding of the viral spike protein (S) to its cellular receptor. The roles of S protein in receptor binding and membrane fusion makes it a prominent target for vaccine development. SARS-CoV-2 genome sequence analysis has shown that this virus belongs to the beta-coronavirus genus, which includes Bat SARS-like coronavirus, SARS-CoV and MERS-CoV. A vaccine should induce a balanced immune response to elicit protective immunity. In this review, we compare and contrast these three important CoV diseases and how they inform on vaccine development.

Prevalence of SARS-CoV-2 in human post-mortem ocular tissues

BACKGROUND

SARS-CoV-2 is found in conjunctival swabs and tears of COVID-19 patients. However, the presence of SARS-CoV-2 has not been detected in the human eye to date. We undertook this study to analyze the prevalence of SARS-CoV-2 in human post-mortem ocular tissues.

METHODS

The expression of SARS-CoV-2 RNA was assessed by RT-PCR in corneal and scleral tissues from 33 surgical-intended donors who were eliminated from a surgical use per Eye Bank Association of America (EBAA) donor screening guidelines or medical director review or positive COVID-19 test. Ocular levels of SARS-CoV-2 RNA (RT-PCR), Envelope and Spike proteins (immunohistochemistry) and anti-SARS-CoV-2 IgG and IgM antibodies (ELISA) in blood were evaluated in additional 10 research-intent COVID-19 positive donors.

FINDINGS

Of 132 ocular tissues from 33 surgical-intended donors, the positivity rate for SARS-CoV-2 RNA was ~13% (17/132). Of 10 COVID-19 donors, six had PCR positive post-mortem nasopharyngeal swabs whereas eight exhibited positive post-mortem anti-SARS-CoV-2 IgG levels. Among 20 eyes recovered from 10 COVID-19 donors: three conjunctival, one anterior corneal, five posterior corneal, and three vitreous swabs tested positive for SARS-CoV-2 RNA. SARS-CoV-2 spike and envelope proteins were detected in epithelial layer of the corneas that were procured without Povidone-Iodine (PVP-I) disinfection.

INTERPRETATIONS

Our study showed a small but noteworthy prevalence of SARS-CoV-2 in ocular tissues from COVID-19 donors. These findings underscore the criticality of donor screening guidelines, post-mortem nasopharyngeal PCR testing and PVP-I disinfection protocol to eliminate any tissue harboring SARS-CoV-2 being used for corneal transplantation.

Handling and treatment strategies of biomedical wastes and biosolids contaminated with SARS-CoV-2 in waste environment

The biomedical waste (BW) generated by hospitals and other health care facilities such as quarantine homes and isolation wards are exponentially increasing amid the COVID-19 pandemic. This has evoked a major challenge for governments worldwide to cope with the increasing demands of waste disposal with limited facilities. Each and every hospital has its own way of managing the waste generated, however, due to the COVID-19 pandemic, there is an intense pressure on health care workers to employ speedy and effective management techniques for the disposal of highly contagious SARS-CoV-2-contaminated BW. The study of survival rates of SARS-CoV-2 on various surfaces such as plastics (2–3 days), clothes (7 days), and wood (<24 h) has helped to deploy various disinfection processes such as treatment of contaminated surfaces with 70% ethanol and 0.05% sodium hypochlorite. Additionally, various effective waste processing procedures such as incineration and autoclaving for the disposal of infected masks, personal protective equipment (PPE) kits, towels, and tissues have been recommended. This chapter is focused on the detailed discussion on the characteristics and classification of wastes generated from health care sectors and management strategies with an emphasis on COVID-19.

Neurological manifestations temporally associated with SARS-CoV-2 infection in pediatric patients in Mexico

PURPOSE

To describe the temporal association of specific acute neurological symptoms in pediatric patients with confirmed SARS-CoV-2 infection between May and August 2020.

METHODS

We performed a recollection of all the clinical and laboratory data of patients having acute neurological symptoms temporally associated with SARS-CoV-2 infection at a third-level referral hospital in Mexico City (Instituto Nacional de Pediatría). Patients in an age group of 0-17 years with acute neurological signs (including ascending weakness with areflexia, diminished visual acuity, encephalopathy, ataxia, stroke, or weakness with plasma creatinine kinase (CK) elevation) were evaluated.

RESULTS

Out of 23 patients with neurological manifestations, 10 (43%) had a confirmed SARS-CoV-2 infection. Among the infected patients, 5 (50%) were males aged 2-16 years old (median age 11.8 years old). Four (40%) patients confirmed a close contact with a relative positive for SARS-CoV-2, while 6 (60%) cases had a history of SARS-CoV-2-related symptoms over the previous 2 weeks. The following diagnoses were established: 3 cases of GBS, 2 of ON, 2 of AIS, one of myositis with rhabdomyolysis, one ACA, and one of anti-NMDA-R encephalitis.

CONCLUSIONS

Neurological manifestations temporally associated with SARS-CoV-2 infection were noticed in the pediatric population even without respiratory symptoms. In this study, 2 of 6 symptomatic patients had mild respiratory symptoms and 4 had unspecific symptoms. During this pandemic, SARS-CoV-2 infection should be considered as etiology in patients with acute neurological symptoms, with or without previous respiratory manifestations, particularly in teenagers.

Ocular manifestations of SARS-CoV-2: Literature review

In this review, a summary is presented of the main reports regarding the potential ocular manifestations of the new coronavirus disease (COVID-19). Scientific evidence is based on letters to the editor, clinical cases and case series, cross-sectional, and a few longitudinal studies. To date, it includes viral conjunctivitis, immune conjunctivitis, and oculomotor palsies (OCP) due to the novel coronavirus. Retinopathy is discussed. A viral conjunctivitis outbreak can be isolated or associated with the systemic picture, mainly pulmonary, before or after the onset of respiratory symptoms. It can be both unilateral and bilateral, follicles are typical, and duration is variable between 5 and 21 days. Immune-mediated conjunctivitis consists of eye redness, together with erythroderma and fever. It appears more frequently in children, and has been associated with a «Kawasaki-like» disease and toxic shock syndrome. OCP can present on its own, or as part of Miller-Fisher syndrome, along with ataxia, and hyporeflexia. Ophthalmologists have a considerable risk of developing COVID-19 due to close contact with the patient, exposure to tears and eye secretions, and the use of various pieces of equipment and devices susceptible to contamination.

COVID-19 retinal microangiopathy as an in vivo biomarker of systemic vascular disease?

IMPORTANCE

COVID-19 is caused by SARS-CoV-2, a betacoronavirus that uses the angiotensin-converting enzyme-related carboxypeptidase (ACE2) receptor to gain entry into cells. ACE2 receptor is widely expressed in multiple organs, including the retina, an extension of the central nervous system. The ACE2 receptor is involved in the diabetic and hypertensive retinopathy. Additionally, coronaviruses cause ocular infections in animals, including retinitis, and optic neuritis.

OBJECTIVE

To assess whether there is any retinal disease associated with COVID-19.

DESIGN

We have evaluated 27 asymptomatic subjects, with retinal fundoscopic, optical coherence tomography (OCT) and OCT angiography fourteen days after hospital discharge due to COVID-19 bilateral pneumonia.

RESULTS

Cotton wool exudates were evident in six out of 27 patients evaluated, a 22%. Cotton wool exudates are a marker vascular disease severity in other medical context, that is diabetes and hypertension, and are associated with increased risk for acute vascular events. Whether antiaggregation therapy may play a role on fundoscopic-selected patients with COVID-19 requires prospective trials.

Can the coronavirus disease 2019 (COVID-19) cause choroiditis and optic neuropathy?

Objectives: We aim to investigate the involvement of the choroid and retinal nerve fiber layer (RNFL) in COVID-19 patients using spectral domain optical coherence tomography.

Methods: This cross-sectional study was conducted between April and June 2020. 40 patients (23 female and 17 male) with COVID-19 and 42 healthy individuals (26 female and 16 male) were included in the study. The OCT scans were performed 4 weeks after the COVID-19 diagnosis.

Results: In the COVID-19 group, in the right eyes, the mean nasal choroidal thickness was 295.70 ± 7,046 μm ( p = 0.017), mean subfoveal choroidal thickness was 333.25 ± 6,353 μm ( p = 0.003), mean temporal choroidal thickness was 296.63 ± 6,324 μm ( p = 0.039), and mean RNFL was 89.23 ± 1.30 μm ( p = 0.227). In the left eyes, mean nasal choroidal thickness was 287.88 ± 9,033 μm ( p = 0.267), mean subfoveal choroidal thickness was 333.80 ± 9,457 μm ( p = 0.013), mean temporal choroidal thickness was 298.50 ± 9,158 μm ( p = 0.079), and mean RNFL was 89.48 ± 1,289 μm ( p = 0.092). Compared with the control group, the patient group had significant thickening of the choroidal thickness in all quadrants of the right eyes, and significant thickening of the subfoveal choroidal thickness in the left eyes. There was no significant difference in the RNFL thickness between groups ( p > 0.05).

Conclusion: COVID-19 may cause a subclinical involvement in the choroidal layer.

Optimized and Non-Optimized Personal Protective Equipment Use during the COVID-19 Pandemic in Thailand: A National Cross-Sectional Survey in a Resource-Limited Setting

INTRODUCTION

Coronavirus disease (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV2). COVID-19 is highly contagious, potentially fatal, and a global public health concern. Combining optimized personal protective equipment (PPE) use and hand hygiene is the best strategy for preventing COVID-19 in health care workers (HCWs).

METHODS

We conducted a national cross-sectional web-based survey of HCWs in the infection control program (IPC) in Thailand between May 5, 2020 and May 15, 2020. The primary objective was the prevalence of optimized PPE use amongst HCWs. The secondary objective was identification of the independent predictors of optimized PPE use.

RESULTS

We received a response from 46% of HCWs (756/1650), and all those who responded were nurse or HCWs who were registered in the IPC network. Five HCWs were excluded because of missing data, and 751 were included in the final analysis. The prevalences of PPE use were 22% (168/751) for optimized PPE use, 78% (583/751) for non-optimized PPE use, 35% (263/751) for PPE overuse, and 43% (320/751) for PPE underused. In univariate analysis, optimized PPE use was significantly associated with age, education level, knowledge of appropriate negative pressure room selection, and knowledge of apparently milder symptom severity in children than adults. In multivariate analysis, independent predictors of optimized PPE use were knowledge of appropriate negative pressure room selection (aOR = 1.95, 95% CI = 1.18-3.22), the difference in symptom severity between children and adults (aOR = 0.55, 95% CI = 0.37-0.81), and education level (aOR = 1.54, 95% CI = 1.04-2.27).

CONCLUSION

The prevalence of optimized PPE use amongst HCWs was 22%. Independent predictors of optimized PPE use were COVID-19 knowledge-based factors and education level. Therefore, the continued education training program should be implemented to ensure maintenance of appropriate practices during the COVID-19 pandemic.

Otorhinolaryngological and Ophthalmological Manifestations of COVID-19 in the Pediatric Population

Severe Acute Respiratory Syndrome Coronavirus 2 pandemic has affected several countries throughout the world. Being very contagious, it can affect any individual. So far, the prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 in children amongst the total infected population is very low, ranging from 1-5%. Difficulty in diagnosing the disease clinically in the pediatric population owing to their inability to explain their symptoms often renders a possibility of overlooking this disease. Moreover, new modes of presentation are being reported apart from the classical tell-tale signs. In this scenario, medical professionals dealing with the children should be well aware of different modes of presentation of this disease in the pediatric population. This study thus aims to review otorhinolaryngological and ophthalmological manifestations in the pediatric population affected by Severe Acute Respiratory Syndrome Coronavirus 2.

COVID-19: A Global Challenge with Old History, Epidemiology and Progress So Far

Humans have witnessed three deadly pandemics so far in the twenty-first century which are associated with novel coronaviruses: SARS, Middle East respiratory syndrome (MERS), and COVID-19. All of these viruses, which are responsible for causing acute respiratory tract infections (ARTIs), are highly contagious in nature and/or have caused high mortalities. The recently emerged COVID-19 disease is a highly transmittable viral infection caused by another zoonotic novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Similar to the other two coronaviruses such as SARS-CoV-1 and MERS-CoV, SARS-CoV-2 is also likely to have originated from bats, which have been serving as established reservoirs for various pathogenic coronaviruses. Although, it is still unknown how SARS-CoV-2 is transmitted from bats to humans, the rapid human-to-human transmission has been confirmed widely. The disease first appeared in Wuhan, China, in December 2019 and quickly spread across the globe, infected 48,539,872 people, and caused 1,232,791 deaths in 215 countries, and the infection is still spreading at the time of manuscript preparation. So far, there is no definite line of treatment which has been approved or vaccine which is available. However, different types of potential vaccines and therapeutics have been evaluated and/or are under clinical trials against COVID-19. In this review, we summarize different types of acute respiratory diseases and briefly discuss earlier outbreaks of coronaviruses and compare their occurrence and pathogenicity with the current COVID-19 pandemic. Various epidemiological aspects of COVID-19 such as mode of spread, death rate, doubling time, etc., have been discussed in detail. Apart from this, different technical issues related to the COVID-19 pandemic including use of masks and other socio-economic problems associated with the pandemic have also been summarized. Additionally, we have reviewed various aspects of patient management strategies including mechanism of action, available diagnostic tools, etc., and also discussed different strategies for the development of effective vaccines and therapeutic combinations to deal with this viral outbreak. Overall, by the inclusion of various references, this review covers, in detail, the most important aspects of the COVID-19 pandemic.

The Ocular Manifestations of COVID-19 Through Conjunctivitis

There is growing evidence that the novel coronavirus (SARS-CoV-2) is capable of transmission through the eye. Research suggests that infection by SARS-CoV-2 can produce an inflammation of the conjunctiva, which leads to redness and itchiness of the eyes. Furthermore, viral particles have been detected in conjunctival secretions of SARS-CoV-2 patients who present with conjunctivitis and is likely another mode of transmission. A 53-year-old male presented with a complaint of left eye irritation and upper eyelid swelling for the past 24 hours. The right eye had mild irritation but no lid swelling. The left upper eyelid was erythematous, swollen and had crusting along the lashes. There were mild inflammation and injection of the conjunctiva. The initial diagnosis was blepharitis, and it was recommended that he continue with the warm compresses, and doxycycline 100 mg to use if the symptoms worsened or did not improve. The patient underwent SARS-CoV-2 PCR testing as a requirement for travel the next day and was found to be positive for the virus. Over the following days, he developed fatigue and rhinitis but clinically improved within six days of his initial presentation. Physicians and health care workers should be aware of the ocular manifestations of SARS-CoV-2 to make a timely diagnosis of infected individuals. While requirements vary across institutions, it is highly recommended that healthcare workers consistently wear appropriate eye protection when interacting with patients to reduce the spread of disease and potential impact on ocular health from SARS-CoV-2. Additionally, to prevent ocular transmission, all healthcare workers should be immediately educated on the importance of eye protection.

A case of bilateral unusual retinal hemorrhages in a COVID-19 patient

PURPOSE

There have been anecdotal reports of ocular manifestations in the Coronavirus Disease 2019 (COVID-19). As the pandemic is spreading and the whole picture is yet unknown, ophthalmologists should be aware of unusual ocular presentations of COVID-19 since they could precede the development of severe respiratory distress.

METHODS

We report here the first case of a patient with bilateral unusual dot-blot retinal hemorrhages and retinal venous dilation who presented shortly thereafter a PCR-proven COVID-19.

CASE REPORT

A 59-year-old woman presented with a 7 days history of blurred vision in both eyes. Fundus examination revealed bilateral venous stasis and dot and blot intra-retinal hemorrhages preceding the diagnosis of COVID-19 in a patient with mild respiratory symptoms that progressed within a few days to a severe respiratory distress. After 1 month of the COVID-19 treatment, fundus examination improved and fluorescein angiography demonstrated no diabetic retinopathy signs, no retinal vasculitis and no significant delay in arterial or venous filling.

CONCLUSION

Intraretinal hemorrhages similar to those found in the retinopathy associated to blood dyscrasias could be an association with SARS-CoV-2 in the context of a coagulopathy induced by the infection.

An Overview of SARS-CoV-2 and Animal Infection

A novel coronavirus has been reported as the causative pathogen of the Coronavirus disease 2019 (COVID-19) outbreak in Wuhan city, China in December 2019. Due to the rapid spread of the virus worldwide, it has been announced as a pandemic by the World Health Organization (WHO). Hospitalized patients in Wuhan were associated with the Huanan seafood wholesale market where live animals, such as poultry, bats, snakes, frogs, rabbits, marmots, and hedgehogs are sold in that market which suggests a possible zoonotic infection. It was suggested that bat is the natural host of SARS-CoV-2, but the intermediate host is still unclear. It is essential to identify the potential intermediate host to interrupt the transmission chain of the virus. Pangolin is a highly suspected candidate as an intermediate host for SARS-CoV-2. Recently, SARS-CoV-2 infection has been reported in cats, dogs, tigers, and lions. More recently SARS-CoV-2 infection affected minks severely and zoonotic transfer with a variant SARS-CoV-2 strain evidenced in Denmark, Netherlands, USA, and Spain suggesting animal-to-human and animal-to-animal transmission within mink farms. Furthermore, experimental studies documented the susceptibility of different animal species to SARS-CoV-2, such as mice, golden hamsters, cats, ferrets, non-human primates, and treeshrews. It is also essential to know the possibility of infection for other animal species. This short review aims to provide an overview on the relation between severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and animals.

Body Localization of ACE-2: On the Trail of the Keyhole of SARS-CoV-2

The explosion of the new coronavirus (SARS-CoV-2) pandemic has brought the role of the angiotensin converting enzyme 2 (ACE2) back into the scientific limelight. Since SARS-CoV-2 must bind the ACE2 for entering the host cells in humans, its expression and body localization are critical to track the potential target organ of this infection and to outline disease progression and clinical outcomes. Here, we mapped the physiological body distribution, expression, and activities of ACE2 and discussed its potential correlations and mutal interactions with the disparate symptoms present in SARS-CoV-2 patients at the level of different organs. We highlighted that despite during SARS-CoV-2 infection ACE2-expressing organs may become direct targets, leading to severe pathological manifestations, and subsequent multiple organ failures, the exact mechanism and the potential interactions through which ACE2 acts in these organs is still heavily debated. Further scientific efforts, also considering a personalized approach aimed to consider specific patient differences in the mutual interactions ACE2-SARS-CoV-2 and the long-term health effects associated with COVID-19 are currently mandatory.

Retinal changes in COVID-19 hospitalized cases

The main objective of this study was to evaluate the retinas of severely or critically ill COVID-19 patients during their hospital stay, at varying time points after symptoms onset. This was a case series observed during May 2020 in two referral centers for COVID-19 treatment in Rio de Janeiro, Brazil. 47 eyes from 25 hospitalized patients with severe or critical confirmed illness were evaluated. A handheld retinal camera was used to acquire bilateral fundus images at several time points after symptoms onset. Electronic health records were retrospectively analyzed and clinical data collected. Severe and critical diseases were noticed in 52% (13/25) and 48% (12/25) of enrolled patients, respectively. Retinal changes were present in 12% (3/25) of patients: a 35 year-old male demonstrated bilateral nerve fiber layer infarcts and microhemorrhages in the papillomacular bundle, but required mechanical ventilation and developed severe anemia and systemic hypotension, acute kidney injury and neurologic symptoms during the course of the disease (critical illness); a 56 year-old male, who required full enoxaparin anticoagulation due to particularly elevated D-dimer (>5.0 mcg/mL), demonstrated unilateral and isolated flame-shaped hemorrhages; and a 49 year-old hypertensive male showed bilateral and discrete retinal dot and blot microhemorrhages. The other 22 patients evaluated did not demonstrate convincing retinal changes upon examination. There was no correlation between disease severity and admission serum levels of CRP, D-dimer and ferritin. This was the first study to show that vascular retinal changes may be present in not insignificant numbers of severe or critical COVID-19 inpatients. These retinal changes, only seen after morbid developments, were likely secondary to clinical intercurrences or comorbidities instead of a direct damage by SARS-CoV-2, and may be important and easily accessible outcome measures of therapeutic interventions and sentinels of neurologic and systemic diseases during COVID-19 pandemic.

Occurrence of SARS-CoV-2 in the intraocular milieu

The purpose of this research is to study the intraocular occurrence of SARS-CoV-2. In postmortem examinations, aqueous humor and the vitreous samples were collected. All individuals were previously positive in nasopharyngeal swabbing and cause of death was respiratory failure due to SARS-CoV-2 infection. Testing was done using quantitative RT-PCR. We included 16 aqueous humor and 16 vitreous samples for PCR testing. None of the results was positive for SARS-CoV-2. Human GAPDH genes to verify the presence of RNA was present in all aqueous humor samples (16/16, 100%) and 15/16 (93.8%) vitreous samples. In conclusion, this case series found no evidence of SARS-CoV-2 in the intraocular milieu.

HDL-scavenger receptor B type 1 facilitates SARS-CoV-2 entry

Responsible for the ongoing coronavirus disease 19 (COVID-19) pandemic, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells through binding of the viral spike protein (SARS-2-S) to the cell-surface receptor angiotensin-converting enzyme 2 (ACE2). Here we show that the high-density lipoprotein (HDL) scavenger receptor B type 1 (SR-B1) facilitates ACE2-dependent entry of SARS-CoV-2. We find that the S1 subunit of SARS-2-S binds to cholesterol and possibly to HDL components to enhance viral uptake in vitro. SR-B1 expression facilitates SARS-CoV-2 entry into ACE2-expressing cells by augmenting virus attachment. Blockade of the cholesterol-binding site on SARS-2-S1 with a monoclonal antibody, or treatment of cultured cells with pharmacological SR-B1 antagonists, inhibits HDL-enhanced SARS-CoV-2 infection. We further show that SR-B1 is coexpressed with ACE2 in human pulmonary tissue and in several extrapulmonary tissues. Our findings reveal that SR-B1 acts as a host factor that promotes SARS-CoV-2 entry and may help explain viral tropism, identify a possible molecular connection between COVID-19 and lipoprotein metabolism, and highlight SR-B1 as a potential therapeutic target to interfere with SARS-CoV-2 infection.

Ocular Involvement in Coronavirus Disease 2019: Up-to-Date Information on Its Manifestation, Testing, Transmission, and Prevention

The coronavirus disease 2019 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still underway. An understanding of the virus's mode of transmission and infection is required for its effective containment. Besides the respiratory and digestive tracts, the ocular surface presents an additional mucosal surface that is exposed to infectious droplets and direct/indirect contact. The relationship between SARS-CoV-2 infection and the eye remains controversial. This review examines up-to-date information on ocular manifestation, laboratory testing, transmission, and prevention of COVID-19. Based on clinical observations, the risk of conjunctivitis in COVID-19 is low. Despite the low incidence, positive SARS-CoV-2 results in eye specimens suggest that the ocular surface may harbor SARS-CoV-2, which may increase the infection and transmission risk. We conclude that the ocular surface remains a potential transmission route for the virus that should not be ignored. In addition, the intraocular findings have also been described in COVID-19. The measures for eye and face protection should be widely adopted to stem the tide of the pandemic.