Ocular tropism of respiratory viruses

Prevalence, Patterns, and Predictors of SARS-CoV-2 RNA and Culturable Virus in Tears of a Case-Ascertained Household Cohort

PURPOSE

To investigate the prevalence, patterns, and predictors of SARS-CoV-2 RNA and culturable virus in tears of a case-ascertained household cohort.

DESIGN

Prospective, longitudinal case-ascertained household cohort identified through convenience sampling.

METHODS

This analysis was restricted to individuals who were non-hospitalized, symptomatic, and tested positive for SARS-CoV-2 by nasal RT-PCR. Tears and anterior nasal biospecimens were serially collected throughout the acute period. Tears specimens were collected by the study staff using Schirmer test strips, and nasal specimens were self-collected. For both, SARS-CoV-2 RNA was quantified using qRT-PCR, and culturable virus was detected using presence of cytopathic effect (CPE) in tissue culture; positive CPE was confirmed by a qRT-PCR step. A series of cross-sectional unadjusted analyses were performed investigating the relationship between different sociodemographic determinants and biological factors associated with tears RNA positivity.

RESULTS

Among the 83 SARS-CoV-2 infected participants, 10 (12%) had at least one RNA-positive tears specimen. Amongst these 10, 5 (50%) had concurrent presence of culturable virus, at a median of 7 days postsymptom onset (IQR: 4-7 days) (absolute range: 4-8 days).

CONCLUSIONS

In this longitudinal cohort, we found evidence of culturable virus in the tears of a small proportion of nonhospitalized SARS-CoV-2 infected individuals. Current public health infection precautions do not account for transmission via tears, so these findings may improve our understanding of potential sources of SARS-CoV-2 transmission and contribute to developing future guidelines.

Detection of SARS-CoV-2 binding receptors and miscellaneous targets as well as mucosal surface area of the human lacrimal drainage system

PURPOSE

Our aim was to evaluate a potential role for the lacrimal drainage system (LDS) as a portal of entry and conduit for SARS-CoV-2 in human infection. We also investigate the mucosal surface area. The relatively long tear contact time in a closed system raises the possibility that this pathway may contribute to the initiation of systemic infection. We looked for expression of ACE2, the main receptor for SARS-CoV-2, as well as cofactors such as TMPRSS2 and other enzymes such as cathepsinB, CD147, elastase1, furin, neuropilin1, neuropilin2, TMPRSS11D and trypsin which also play a role in SARS-CoV-2 infection, in this system.

METHODS

Human tissue samples of the draining tear ducts from body donors were analyzed by RT-PCR, Western blot and immunohistochemistry. It is not known whether the respective body donors were Sars-Cov-2 positive at any time; they were negative when they entered the institute. Besides, the draining LDS of body donors were measured to determine the mucosal surface in the lacrimal system.

RESULTS

The expression of the main receptor studied, ACE2, cofactors such as TMPRSS2 and other enzymes such as cathepsinB, CD147, elastase1, furin, neuropilin1, neuropilin2, TMPRSS11D and trypsin were all detected at the gene and protein level. The average mucosal surface area of the lacrimal sac and nasolacrimal duct was calculated to be 110 mm2.

CONCLUSION

The results show the presence of all analyzed receptors in the efferent LDS. With an average tear passage time of 3 minutes and a relatively large mucosal surface area, the LDS could therefore be considered as a portal of entry and conduit for SARS-CoV-2. In addition, it represents a surface that should be taken into consideration in the administration of topically applied medication to the ocular surface.

Influenza B Virus Receptor Specificity: Closing the Gap between Binding and Tropism

Influenza A and influenza B viruses (FLUAV and FLUBV, respectively) cause significant respiratory disease, hospitalization, and mortality each year. Despite causing at least 25% of the annual disease burden, FLUBV is historically understudied. Unlike FLUAVs, which possess pandemic potential due to their many subtypes and broad host range, FLUBVs are thought to be restricted to only humans and are limited to two lineages. The hemagglutinins (HA) of both influenza types bind glycans terminating in α2,6- or α2,3-sialic acids. For FLUAV, the tropism of human- and avian-origin viruses is well-defined and determined by the terminal sialic acid configuration the HA can accommodate, with avian-origin viruses binding α2,3-linked sialic acids and human-origin viruses binding α2,6-linked sialic acids. In contrast, less is known about FLUBV receptor binding and its impact on host tropism. This review discusses the current literature on FLUBV receptor specificity, HA glycosylation, and their roles in virus tropism, evolution, and infection. While the focus is on findings in the past dozen years, it should be noted that the most current approaches for measuring virus-glycan interactions have not yet been applied to FLUBV and knowledge gaps remain.

Comprehensive Review of COVID-19: Epidemiology, Pathogenesis, Advancement in Diagnostic and Detection Techniques, and Post-Pandemic Treatment Strategies

At present, COVID-19 remains a public health concern due to the ongoing evolution of SARS-CoV-2 and its prevalence in particular countries. This paper provides an updated overview of the epidemiology and pathogenesis of COVID-19, with a focus on the emergence of SARS-CoV-2 variants and the phenomenon known as 'long COVID'. Meanwhile, diagnostic and detection advances will be mentioned. Though many inventions have been made to combat the COVID-19 pandemic, some outstanding ones include multiplex RT-PCR, which can be used for accurate diagnosis of SARS-CoV-2 infection. ELISA-based antigen tests also appear to be potential diagnostic tools to be available in the future. This paper also discusses current treatments, vaccination strategies, as well as emerging cell-based therapies for SARS-CoV-2 infection. The ongoing evolution of SARS-CoV-2 underscores the necessity for us to continuously update scientific understanding and treatments for it.

Ocular Implications of COVID-19 Infection and Vaccine-Related Adverse Events

The COVID-19 pandemic, caused by SARS-CoV-2, has significantly impacted various organ systems, including the eyes. Initially considered a primarily respiratory disease, it is now evident that COVID-19 can induce a range of ocular symptoms. Recognizing these ocular manifestations is crucial for eye care practitioners as they can serve as early indicators of the disease. This review consolidates current evidence on the ocular effects of COVID-19, identifying manifestations such as conjunctivitis, scleritis, uveitis, and retinopathy. The increasing prevalence of these symptoms highlights the importance of thorough eye examinations and detailed patient histories in COVID-19 cases. Potential routes of viral entry into ocular tissues and the underlying mechanisms, including direct infection, immune responses, and vascular involvement, are explored. Additionally, this review addresses ocular side effects associated with COVID-19 vaccines, such as corneal graft rejection, uveitis, and retinal issues. These findings emphasize the need for ongoing surveillance and research to ensure vaccine safety.

Exploring the role of the ocular surface in the lung-eye axis: Insights into respiratory disease pathogenesis

Chronic respiratory diseases (CRDs) represent a significant proportion of global health burden, with a wide spectrum of varying, heterogenic conditions largely affecting the pulmonary system. Recent advances in immunology and respiratory biology have highlighted the systemic impact of these diseases, notably through the elucidation of the lung-eye axis. The current review focusses on understanding the pivotal role of the lung-eye axis in the pathogenesis and progression of chronic respiratory infections and diseases. Existing literature published on the immunological crosstalk between the eye and the lung has been reviewed. The various roles of the ocular microbiome in lung health are also explored, examining the eye as a gateway for respiratory virus transmission, and assessing the impact of environmental irritants on both ocular and respiratory systems. This novel concept emphasizes a bidirectional relationship between respiratory and ocular health, suggesting that respiratory diseases may influence ocular conditions and vice versa, whereby this conception provides a comprehensive framework for understanding the intricate axis connecting both respiratory and ocular health. These aspects underscore the need for an integrative approach in the management of chronic respiratory diseases. Future research should further elucidate the in-depth molecular mechanisms affecting this axis which would pave the path for novel diagnostics and effective therapeutic strategies.

Emergency surgical management for ocular trauma with confirmed COVID-19 symptoms: A case report

INTRODUCTION AND IMPORTANCE

Conducting urgent eye trauma surgery amidst the COVID-19 pandemic poses distinct difficulties, as strict infection control measures are crucial to safeguard both patients and medical staff. Nonetheless, eye trauma remains a significant contributor to avoidable vision loss in developing countries.

CASE PRESENTATION

A 57-year-old man presented with redness, bleeding, and injury in the left eye after a motorcycle accident 9 h prior to hospital admission, along with a torn wound on his left cheek. The visual acuity in the left eye showed no light perception. Limited eye movement in all directions, eyelid hematoma, conjunctival injection, hyphema, and tissue protrusion from the limbus at 6 to 8 o'clock positions were observed. The patient had a history of cataract surgery (+) in both eyes and was diagnosed with an open globe injury with zone II penetrating trauma, accompanied by full hyphema, vitreous and choroid prolapse in the left eye, and a confirmed case of COVID-19. Evisceration of the left eye was performed following the basic guidelines for ocular trauma surgery during the COVID-19 pandemic. Postoperative follow-up was conducted as usual by the operator in isolation for confirmed COVID-19 patients with no significant complaints.

CLINICAL DISCUSSION

Urgent surgical intervention is necessary to prevent visual impairment, following guidelines recommending surgery within 4-72 h. Ocular tissue may facilitate COVID-19 transmission via the nasolacrimal system, posing risks to healthcare workers, particularly during surgery. Preoperative measures, including obtaining COVID-19 status and providing appropriate personal protective equipment (PPE), are crucial. Minimizing aerosol-generating procedures and employing virucidal disinfection further mitigates the transmission risks. This case underscores the need to balance immediate intervention for eye injuries with safety protocols for COVID-19, emphasizing standardized PPE and surgical procedures to safeguard healthcare professionals.

CONCLUSION

Incorporating insights gained during the COVID-19 pandemic will fortify healthcare systems against future pandemics. In particular, it enables effective surgical emergency response while mitigating infectious disease risks.

Dry eye symptoms are prevalent in moderate-severe COVID-19, while SARS-COV-2 presence is higher in mild COVID-19: Possible ocular transmission risk of COVID-19

Purpose

To evaluate the correlation between dry eye symptoms and coronavirus disease 2019 (COVID-19) infection and to assess the real-time reverse transcription-polymerase chain reaction (RT‒PCR) of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) from the conjunctival swab.

Methods

A prospective observational case series study was conducted of all suspected and confirmed COVID-19 patients from Dr. Cipto Mangunkusumo Hospital (RSCM) and the Universitas Indonesia Hospital (RSUI). On the first day of the visit (day 0), systemic clinical symptoms and naso-oropharyngeal (NO) RT‒PCR results will classify all subjects as non-, suspected, or confirmed (mild, moderate, and severe) COVID-19. In all patients, we determined the dry eye symptoms based on the Ocular Surface Disease Index (OSDI) and followed up 7(day 7) and 14 days (day 14) after the first visit. When it was technically possible, we also examined the objective dry eye measurements: tear meniscus height (TMH), noninvasive Keratograph® break-up time (NIKBUT), and ocular redness. Additionally, we took conjunctival swab samples for SARS-CoV-2 RT-PCR in all patients.

Results

The OSDI scores for 157 patients decreased across days 0, 7, and 14 (median (interquartile range): 2.3 (0-8), 0 (0-3), and 0 (0-0), p value < 0.0001 (D0 vs D14). The moderate-severe COVID-19 group had a higher OSDI score than the other groups at median D0 (15.6 vs 0-2.3), p value < 0.0001 and this pattern was consistently seen at follow-up D7 and D14. However, dry eye complaints were not correlated with the three objective dry eye measurements in mild-moderate COVID-19 patients. NO RT‒PCR results were positive in 32 (20.4%) patients, namely, 13 and 19 moderate-severe and mild COVID-19 patients, respectively. Positive RT‒PCR results were observed in 7/157 (4.5%) conjunctival swab samples from 1 in non-COVID-19 group and 6 in mild group.

Conclusion

In the early phase of infection, COVID-19 patients experience dry eye symptoms, which have no correlation with objective dry eye measurements. SARS-CoV-2 in conjunctival swab samples can be detected in patients with normal-to-mild COVID-19, which shows the risk of ocular transmission.

New disposable esthesiometer (KeraSenseⓇ) to improve diagnosis and management of neurotrophic keratitis

PURPOSE

To validate the use, repeatability, and reproducibility of a new, cost-effective, disposable, sterile device (KeraSenseⓇ, Dompè farmaceutici SpA, Milan Italy) compared to Cochet-Bonnet (CB) esthesiometer. Secondly, to identify a simple, safe, rapid, and low-cost test to diagnose neurotrophic keratitis (NK).

METHODS

16 patients with diagnosis of NK stage I, 25 patients with diabetes mellitus (DM), and 26 healthy subjects were included in the study. Corneal sensitivity (CS) was assessed by CB and KeraSenseⓇ. Repeatability, accuracy, and reproducibility of the novel disposable aesthesiometer were assessed. Specificity, sensitivity, and cut-off value for NK diagnosis were calculated by ROC curve analysis.

RESULTS

All NK patients showed a CS ≤ 40 mm, while none of the healthy patients showed a CS value < 50 mm. Significant agreement was found between CB measurements and the single use esthesiometer evaluations of CS (p < 0.001). Repeatability evaluations of the single use esthesiometer showed 100% agreement between different measurements (p < 0.001). Reproducibility evaluations showed 99.6% concordance between different operators (p < 0.001). A 55 mm value of the single use esthesiometer was adequate to exclude an NK diagnosis, while all NK patients showed a value ≤ 35 mm.

CONCLUSIONS

Corneal hypo/anaesthesia is considered the hallmark of NK. The use of the novel single-use esthesiometer will allow for a diagnostic improvement in NK, sparing time and guaranteeing patients' safety. Diabetic patients despite normal corneal findings may show impairment of CS, suggesting a preclinical stage of NK, requiring a close follow-up.

Detection of infectious SARS-CoV-2 in ocular samples is linked to viral load in the nasopharynx

Introduction

SARS-CoV-2 is known to infect respiratory tissue cells. However, less is known about infection of ocular tissue and potential infectivity of lacrimal fluid. With this study, we want to compare viral loads in eye and nasopharyngeal swabs and analyze these for infectious virus.

Methods

Between May 2020 and April 2021 ocular and nasopharyngeal swabs were collected from 28 SARS-CoV-2 infected patients treated on the corona virus disease 2019 (COVID-19)-ward of the University Hospital of Innsbruck, Austria. Samples with PCR detectable SARS-CoV-2 were analyzed via whole genome sequencing and an attempt was made to isolate infectious virus.

Results

At the time point of sample collection, 22 individuals were still PCR positive in nasopharyngeal samples and in 6 of these patients one or both ocular samples were additionally positive. CT-values in eyes were generally higher compared to corresponding nasopharyngeal samples and we observed a tendency for lower CT-values, i.e. increased viral load, in nasopharyngeal swabs of individuals with at least one infected eye, compared to those where ocular samples were PCR negative. Ocular and nasopharyngeal sequences from the same patient were assigned to the same variant, either the D614G or the Alpha variant. Infectious virus was successfully isolated from 9 nasopharyngeal swabs, however only from one of the seven PCR positive ocular samples.

Conclusion

We could detect SARS-CoV-2 in eyes of some of the infected patients albeit at lower levels compared to nasopharyngeal swabs. However, our results also indicate that lacrimal fluid might be infectious in patients with high viral load.

Respiratory infection transmission risk and indoor air quality at outpatient departments and emergency treatment units of Sri Lankan teaching hospitals

Indoor carbon dioxide (CO2) concentration has been used as a proxy of the degree of ventilation and, by extension, as an indicator of the risk of contracting respiratory infections. No publications exist regarding indoor air quality (IAQ) parameters of Sri Lankan hospitals.We measured the levels of CO2 and seven other IAQ parameters during morning rush hours for three days, in outpatient departments (OPDs) and emergency treatment units (ETUs) of all 21 teaching hospitals of Sri Lanka. We measured the same parameters of outdoor air also. We calculated the mean values of those parameters. We looked for correlations between outdoors and OPD and ETU levels of selected air quality parameters.The average CO2 levels of outdoors, OPDs and ETUs respectively were 514ppm (ppm = parts per million), 749ppm and 795ppm. The average levels of PM2.5 (particulate matter with diameters <2.5μm) outdoors, OPDs and ETUs respectively, were 28.7μg/m3,32μg/m3 and 25.6 μg/m3. The average levels of PM10 (particulate matter with diameters <10μm) outdoors, OPDs and ETUs respectively, were 49.4μg/m3, 55.5μg/m3 and 47.9 μg/m3. The median levels of formaldehyde outdoors, OPDs and ETUs respectively, were 0.03mg/m3, 0.04mg/m3 and 0.08mg/m3. The median levels of total volatile organic compounds (VOC) outdoors, OPDs and ETUs respectively were 0.12mg/m3, 0.19mg/m3 and 0.38mg/m3.CO2 levels of air in OPDs and ETUs generally were below the national ceilings but above the ceilings used by some developed countries. Outdoors, OPDs and ETUs air contain PM10, PM2.5 levels higher than WHO ceilings, although below the national ceilings. VOC and formaldehyde levels are generally below the national ceilings. Air in OPDs and ETUs is hotter and humid than national ceilings. Outdoor PM10, PM2.5 levels influence OPDs and ETUs levels. We propose methods to reduce the risk of nosocomial respiratory infections and to improve IAQ of Sri Lankan OPDs and ETUs.

Eyeglasses and risk of COVID-19 transmission-analysis of the Virus Watch Community Cohort study

OBJECTIVES

The importance of SARS-CoV-2 transmission via the eyes is unknown, with previous studies mainly focusing on protective eyewear in healthcare settings. This study aimed to test the hypothesis that wearing eyeglasses is associated with a lower risk of COVID-19.

METHODS

Participants from the Virus Watch prospective community cohort study responded to a questionnaire on the use of eyeglasses and contact lenses. Infection was confirmed through data linkage, self-reported positive results, and, for a subgroup, monthly capillary antibody testing. Multivariable logistic regression models, controlling for age, sex, income, and occupation, were used to identify the odds of infection depending on frequency and purpose of eyeglasses or contact lenses use.

RESULTS

A total of 19,166 participants responded to the questionnaire, with 13,681 (71.3%, CI 70.7-72.0) reporting they wore eyeglasses. Multivariable logistic regression model showed a 15% lower odds of infection for those who reported using eyeglasses always for general use (odds ratio [OR] 0.85, 95% 0.77-0.95, P = 0.002) compared to those who never wore eyeglasses. The protective effect was reduced for those who said wearing eyeglasses interfered with mask-wearing and was absent for contact lens wearers.

CONCLUSIONS

People who wear eyeglasses have a moderate reduction in risk of COVID-19 infection, highlighting that eye protection may make a valuable contribution to the reduction of transmission in community and healthcare settings.

COVID-19 and the eye

There is growing literature describing the ocular manifestations of COVID-19. We have assessed published reviews, cross-sectional analyses, and clinical reports to summarize the ocular manifestations of the disease and available vaccines, identify the potential role of ocular transmission, and offer basic clinical guidance to health care providers. Ultimately, self-limiting conjunctivitis and conjunctival hyperemia are the most frequently reported ocular findings; several rarer entities may warrant targeted topical therapies. COVID-19 vaccines have been infrequently associated with the development of rare but significant side effects that may warrant ophthalmologist referral as well as specific treatments. Despite the overall low risk of ocular transmission, eye protection is advisable for health care providers in high-risk scenarios. This review should help to guide the assessment of patients with eye complaints in the setting of COVID-19 to promote appropriate diagnosis, treatment, monitoring, and referral.

Intravenous Immunoglobulins for Bilateral Retinochoroiditis in Rhinovirus Infection: A Case Report

A 43-year-old woman presented bilateral anterior granulomatous uveitis associated with bilateral disc edema and bilateral peripheral retinochoroidal lesions. Intravenous corticosteroids after negative investigations for infectious causes did not prevent spreading of the lesions and retinal atrophy. A diagnostic vitrectomy with vitreous analysis, including pan-genomic, next-generation sequencing showed a positive result for rhinovirus HRV B91, and the cytological analysis was suggestive of infection. Intravenous immunoglobulins associated with pegylated interferon-alpha strongly slowed the progression of the lesions and led to scarred and atrophic aspect in both eyes after 6 months. [Ophthalmic Surg Lasers Imaging Retina 2023;54:720-722.].

Broad-Spectrum Antimicrobial Activity of Oftasecur and Visuprime Ophthalmic Solutions

Due to the wide etiology of conjunctivitis, the expensive and time-consuming diagnosis requires new therapeutic strategies with broad-spectrum antimicrobial activity and nonselective mechanisms of action. In this context, eye drops could provide an alternative to conventional antimicrobial therapies. Here, we compare the antibacterial and antiviral activity of Oftasecur and Visuprime, commercially available ophthalmic solutions. Cytotoxicity assay was performed on Vero CCL-81 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) test. Antibacterial efficacy was evaluated on Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae by disk diffusion, broth microdilution methods, and time-killing tests. Furthermore, the antiviral activity against HSV-1 was estimated by co-treatment, cell and viral pretreatment and post-treatment, via plaque reduction assay, fluorescence assessment (GFP-engineered HSV-1), and real-time PCR. After 24 h of exposure, Oftasecur and Visuprime showed a volume-inducing 50% of cytotoxicity of 125 and 15.8 μL, respectively Oftasecur and Visuprime induced 90% antibacterial activity in response to mean volume of 10.0 and 4.4 µL for Gram-positive and Gram-negative strains, respectively. Oftasecur exerted bactericidal action on both bacterial populations, while Visuprime was bacteriostatic on Gram-negative strains and slightly bactericidal on Gram-positive bacteria. A major impact on infectivity occurred by exposure of viral particles to the ophthalmic solutions. In detail, 50% of inhibition was verified by exposing the viral particles to 3.12 and 0.84 μL of Oftasecur and Visuprime, respectively, for 1 h. The reduction of the fluorescence and the expression of the viral genes confirmed the recorded antiviral activity. Due to their high antimicrobial efficiency, Oftasecur and Visuprime could represent a valid empirical strategy for the treatment of conjunctivitis.

SARS-CoV-2 cellular tropism and direct multiorgan failure in COVID-19 patients: Bioinformatic predictions, experimental observations, and open questions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), has led to an unprecedented public health emergency worldwide. While common cold symptoms are observed in mild cases, COVID-19 is accompanied by multiorgan failure in severe patients. Organ damage in COVID-19 patients is partially associated with the indirect effects of SARS-CoV-2 infection (e.g., systemic inflammation, hypoxic-ischemic damage, coagulopathy), but early processes in COVID-19 patients that trigger a chain of indirect effects are connected with the direct infection of cells by the virus. To understand the virus transmission routes and the reasons for the wide-spectrum of complications and severe outcomes of COVID-19, it is important to identify the cells targeted by SARS-CoV-2. This review summarizes the major steps of investigation and the most recent findings regarding SARS-CoV-2 cellular tropism and the possible connection between the early stages of infection and multiorgan failure in COVID-19. The SARS-CoV-2 pandemic is the first epidemic in which data extracted from single-cell RNA-seq (scRNA-seq) gene expression data sets have been widely used to predict cellular tropism. The analysis presented here indicates that the SARS-CoV-2 cellular tropism predictions are accurate enough for estimating the potential susceptibility of different cells to SARS-CoV-2 infection; however, it appears that not all susceptible cells may be infected in patients with COVID-19.

Coronavirus disease 2019: Repeated immersion of chlorine-containing disinfectants has adverse effects on goggles

Introduction

During COVID-19, some front-line personnel experienced varying degrees of eye discomfort due to the use of goggles repeatedly disinfected with chlorine-containing disinfectant.

Methods

The eye damage information of 276 front-line personnel who used goggles in a hospital from October 1, 2021, to December 1, 2021, was collected by filling out a questionnaire. To study the effect of chlorinated disinfectants on goggles, we immersed the goggles in the same volume of water and chlorinated disinfectant buckets. We tested the light transmittance, color and texture, and airtightness of the goggles at different times (1, 3, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, 216, 240, and 268 h). In addition, we detected where chlorinated disinfectant remained in the goggles by using disinfectant concentration test paper.

Results

60 (21.82%) people experienced dry eyes, stinging pain, photophobia and tearing, conjunctival congestion, eyelid redness, and swelling. After treatment or rest, the patient's ocular symptoms were significantly relieved within 3 days. With the extension of disinfection time, the light transmission of the lenses gradually decreased, and the light transmission reduced when immersion occurred at 216 h. After 72 h of disinfection, the color of the goggle frame began to change to light yellow, the texture gradually became hard and brittle, and the color became significantly darker at 268 h of disinfection. The airtightness of the goggles began to decrease after 168 h of disinfection, the airtightness decreased substantially at 268 h, and the shape changed significantly. In addition, the concentration test paper results show that the disinfection solution mainly resides in the goggle frame seam and goggles' elastic bands' bundle.

Conclusions

Repeated chlorine disinfectant disinfection will reduce the effectiveness of goggles protection and damage front-line personnel's eye health.

Detection of coronavirus in tear samples of hospitalized patients with COVID-19

PURPOSE

To assess the presence of viral RNA in conjunctival secretions and tears of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients in terms of a possible ocular transmission route and also to examine whether a difference between the patients with and without ocular surface positivity existed.

METHODS

A prospective cross-sectional study of 70 consecutive patients who were hospitalized in Haseki Training and Research Hospital with SARS-CoV-2 from February 1 to April 1, 2021, was performed. Tears and conjunctival secretions were collected within 24 h of nasopharyngeal sample collection and examined for SARS-CoV-2 using reverse transcription real-time polymerase chain reaction (qPCR). The clinical data, results of blood tests and nasopharyngeal and conjunctival swabs, and CT findings were evaluated for all patients.

RESULTS

Seventy patients (37 males, 33 females) were included in this study. Tear-conjunctival samples from eight patients (11.42%) yielded positive PCR results although these eight patients had no eye symptoms or conjunctivitis. In patients with positive conjunctival PCR results, cycle threshold values for conjunctival samples were higher than those for nasopharyngeal samples. All findings (except gender) were similar between patients with either positive or negative conjunctival swab samples. All patients with positive conjunctival swab samples were male; however, the male ratio in patients with negative conjunctival swab samples was only 46.77%.

CONCLUSION

In our study, the rate of conjunctival swab PCR positivity was 11.42%. It appears that even in the absence of ocular symptoms, SARS-CoV-2 virus may be present on the ocular surface; therefore, the ocular surface may be a significant viral transmission route.

[Ophthalmic manifestations of COVID-19]

In March 2020 the World Health Organization (WHO) declared a pandemic of the novel coronavirus infection (COVID-19) caused by the SARS-CoV-2 respiratory virus. The high spread rate of the virus and the severity of the course of the disease are of great clinical and epidemiological significance, making it relevant for ophthalmologists to study the mechanisms of how SARS-CoV-2 infects ocular structures, as well as possible clinical manifestations of the infection in the organ of vision. This review contains analysis, systematization, and generalization of epidemiological and clinical data on SARS-CoV-2 ocular lesions and was carried out with the data found in scientific abstract databases. The article presents main clinical ophthalmic manifestations of COVID-19, lists the utilized schemes of etiotropic and symptomatic therapy, recommended preventive measures, and considers the possible ophthalmic complications after vaccination against COVID-19.

Ocular manifestations of COVID-19 in pediatric patients

The coronavirus disease-19 (COVID-19) infection may remain asymptomatic or may have several different presentations. Although this disease primarily affects the respiratory system, systemic manifestations affecting the gastrointestinal, cardiovascular, neurological, otorhinolaryngologic, and ophthalmic systems have been reported. Ophthalmic signs may be the first and only sign of COVID-19 infection in children. In the current narrative review, we report the ophthalmic manifestations of COVID-19 in the pediatric age cohort. We performed a comprehensive literature search for the publications on ophthalmic manifestations of COVID-19 in children between 1 March 2020 and 1 January 2022 and compiled the ophthalmic manifestations of this entity among the pediatric population. Conjunctivitis is the most common ophthalmic manifestation in children and can develop at any stage of the disease. Ophthalmic manifestations are seen more commonly in children with severe systemic disease. Long-term and indirect consequence of the COVID-19 disease is the rise of myopia among children. Ophthalmic signs may be the first and only sign of COVID-19 infection in children. Pediatricians, as well as ophthalmologists, must keep observing all children with COVID-19 closely for ophthalmic signs.

Detection of Airborne Influenza A and SARS-CoV-2 Virus Shedding following Ocular Inoculation of Ferrets

Despite reports of confirmed human infection following ocular exposure with both influenza A virus (IAV) and SARS-CoV-2, the dynamics of virus spread throughout oculonasal tissues and the relative capacity of virus transmission following ocular inoculation remain poorly understood. Furthermore, the impact of exposure route on subsequent release of airborne viral particles into the air has not been examined previously. To assess this, ferrets were inoculated by the ocular route with A(H1N1)pdm09 and A(H7N9) IAVs and two SARS-CoV-2 (early pandemic Washington/1 and Delta variant) viruses. Virus replication was assessed in both respiratory and ocular specimens, and transmission was evaluated in direct contact or respiratory droplet settings. Viral RNA in aerosols shed by inoculated ferrets was quantified with a two-stage cyclone aerosol sampler (National Institute for Occupational Safety and Health [NIOSH]). All IAV and SARS-CoV-2 viruses mounted a productive and transmissible infection in ferrets following ocular inoculation, with peak viral titers and release of virus-laden aerosols from ferrets indistinguishable from those from ferrets inoculated by previously characterized intranasal inoculation methods. Viral RNA was detected in ferret conjunctival washes from all viruses examined, though infectious virus in this specimen was recovered only following IAV inoculation. Low-dose ocular-only aerosol exposure or inhalation aerosol exposure of ferrets to IAV similarly led to productive infection of ferrets and shedding of aerosolized virus. Viral evolution during infection was comparable between all inoculation routes examined. These data support that both IAV and SARS-CoV-2 can establish a high-titer mammalian infection following ocular exposure that is associated with rapid detection of virus-laden aerosols shed by inoculated animals. IMPORTANCE Documented human infection with influenza viruses and SARS-CoV-2 has been reported among individuals wearing respiratory protection in the absence of eye protection, highlighting the capacity of these respiratory tract-tropic viruses to exploit nonrespiratory routes of exposure to initiate productive infection. However, comprehensive evaluations of how ocular exposure may modulate virus pathogenicity and transmissibility in mammals relative to respiratory exposure are limited and have not investigated multiple virus families side by side. Using the ferret model, we show that ocular exposure with multiple strains of either coronaviruses or influenza A viruses leads to an infection that results in shedding of detectable aerosolized virus from inoculated animals, contributing toward onward transmission of both viruses to susceptible contacts. Collectively, these studies support that the ocular surface represents a susceptible mucosal surface that, if exposed to a sufficient quantity of either virus, permits establishment of an infection which is similarly transmissible as that following respiratory exposure.

Eye damage in COVID-19. Part 1: Involvement of the eye in SARS-CoV-2 virus transmission and anterior segment complications

In COVID-19, eye damage may develop at any stage of the disease. Viral ribonucleic acid has been found in ocular tissues, but the role of the eye as a route of infection is yet to be substantiated. Ophthalmic manifestations may be a typical feature of COVID-19 infection or they may develop several weeks after recovery. Ophthalmologists should be aware of possible relationships of an ophthalmic pathology with SARS-CoV-2 in order to obtain targeted case history, detect the specific signs, prescribe the necessary tests and thereby reduce the spread of the infection. These relationships are also important for early diagnosis and treatment of complications that threaten the patients’ life and vision. The first part of the review focuses on the possible involvement of the eye in SARS-CoV-2 infection and the spread of infection. Clinical manifestations of the anterior segment damage are considered.

Ocular tropism of SARS-CoV-2 in animal models with retinal inflammation via neuronal invasion following intranasal inoculation

Although ocular manifestations are reported in patients with COVID-19, consensus on ocular tropism of SARS-CoV-2 is lacking. Here, we infect K18-hACE2 transgenic mice with SARS-CoV-2 using various routes. We observe ocular manifestation and retinal inflammation with production of pro-inflammatory cytokines in the eyes of intranasally (IN)-infected mice. Intratracheal (IT) infection results in dissemination of the virus from the lungs to the brain and eyes via trigeminal and optic nerves. Ocular and neuronal invasions are confirmed using intracerebral (IC) infection. Notably, the eye-dropped (ED) virus does not cause lung infection and becomes undetectable with time. Ocular and neurotropic distribution of the virus in vivo is evident in fluorescence imaging with an infectious clone of SARS-CoV-2-mCherry. The ocular tropic and neuroinvasive characteristics of SARS-CoV-2 are confirmed in wild-type Syrian hamsters. Our data can improve the understanding regarding viral transmission and clinical characteristics of SARS-CoV-2 and help in improving COVID-19 control procedures.

Inhibition of coronavirus HCoV-OC43 by targeting the eIF4F complex

The translation initiation complex 4F (eIF4F) is a rate-limiting factor in protein synthesis. Alterations in eIF4F activity are linked to several diseases, including cancer and infectious diseases. To this end, coronaviruses require eIF4F complex activity to produce proteins essential for their life cycle. Efforts to target coronaviruses by abrogating translation have been largely limited to repurposing existing eIF4F complex inhibitors. Here, we report the results of a high throughput screen to identify small molecules that disrupt eIF4F complex formation and inhibit coronavirus RNA and protein levels. Of 338,000 small molecules screened for inhibition of the eIF4F-driven, CAP-dependent translation, we identified SBI-1232 and two structurally related analogs, SBI-5844 and SBI-0498, that inhibit human coronavirus OC43 (HCoV-OC43; OC43) with minimal cell toxicity. Notably, gene expression changes after OC43 infection of Vero E6 or A549 cells were effectively reverted upon treatment with SBI-5844 or SBI-0498. Moreover, SBI-5844 or SBI-0498 treatment effectively impeded the eIF4F complex assembly, with concomitant inhibition of newly synthesized OC43 nucleocapsid protein and OC43 RNA and protein levels. Overall, we identify SBI-5844 and SBI-0498 as small molecules targeting the eIF4F complex that may limit coronavirus transcripts and proteins, thereby representing a basis for developing novel therapeutic modalities against coronaviruses.

Conjunctival Swabs Reveal Higher Detection Rate Compared to Schirmer Strips for SARS-CoV-2 RNA Detection in Tears of Hospitalized COVID-19 Patients

Purpose: To determine the prevalence of SARS-CoV-2 in tear samples and to investigate whether it correlates with ocular findings and patients’ prognosis in Brazil. Methods: Tears were collected using Schirmer strips (SS) and conjunctival swabs (CS) from patients hospitalized with laboratory-confirmed SARS-CoV-2 infection. Samples were analyzed using qRT-PCR. Demographic and clinical data, ocular symptoms, and Schirmer tests (ST) were collected from patients. Charlson Comorbidity Index (CCI) was used to rate comorbidities, and patients were monitored until hospital discharge or death. Results: There were 61 hospitalized patients, 33 of which were diagnosed with COVID-19. Within the confirmed COVID-19 patients, SARS-CoV-2 was detected in 18.2% (n = 6) of CS and 12.1% (n = 4) of SS samples. Subjective and objective parameters for dry eye syndrome (e.g., ST COVID-19: 8.3 ± 6.4mm, non-COVID-19: 8.9 ± 6.6mm, p > 0.05) were comparable between COVID-19 (n = 33) and non-COVID-19 patients (n = 28). Among the 16 COVID-19 patients exhibiting ocular symptoms, only tearing was reported significantly more frequently when tear samples were positive for SARS-CoV-2 (p < 0.05). Strikingly, patients whose tears tested positive for SARS-CoV-2 had significantly inferior CCI (pos.: 34.0 ± 31.8%, neg.: 67.6 ± 36.4%, p < 0.05) and higher mortality rates (pos.: 50.0%, neg.: 7.4%, p < 0.01). Conclusions: SARS-CoV-2 was detected with a prevalence of 18.2% on the ocular surface. Decreased CCI and increased mortality rate in the positive tear group suggests that viral detection may relate to prognosis and highlight the need of personal protective measures for healthcare professionals. Most of the patients, regardless of COVID-19 diagnosis, had low tear production and eye discomfort, possibly pointing to the need for artificial tear use during hospitalization.

Viral Infection and Antiviral Treatments in Ocular Pathologies

Ocular viral infections are common and widespread globally. These infectious diseases are a major cause of acute red eyes and vision loss. The eye and its nearby tissues can be infected by several viral agents, causing infections with a short course and limited ocular implications or a long clinical progression and serious consequences for the function and structure of the ocular region. Several surveillance studies underline the increased emergence of drug resistance among pathogenic viral strains, limiting treatment options for these infections. Currently, in the event of resistant infections, topical or systemic corticosteroids are useful in the management of associated immune reactions in the eye, which contribute to ocular dysfunction. Many cases of viral eye infections are misdiagnosed as being of bacterial origin. In these cases, therapy begins late and is not targeted at the actual cause of the infection, often leading to severe ocular compromises, such as corneal infiltrates, conjunctival scarring, and reduced visual acuity. The present study aims at a better understanding of the viral pathogens that cause eye infections, along with the treatment options available.

Knowledge, attitude and practices of Saudi dental hygiene students towards novel corona virus disease (COVID-19): A nation-wide study

INTRODUCTION

Healthcare workers involved in procedures that generate aerosol or handling patient specimens are associated with a high possibility of COVID-19 infection. Thus, it is very important for the health workers to understand the knowledge related to transmission, prevention and protocols of COVID-19.

METHODS

Cross-sectional questionnaire study was conducted on dental hygiene students in Saudi Arabia. An online version of pre-tested and validated questionnaire was used to test the KAP for COVID 19.

RESULTS

The mean score for knowledge-related questions was found to be 2.91 ± 1.59, attitude-related questions to be 2.84 ± 1.41 and for practice-related questions to be 4.20 ± 1.36. After converting the scores into percentages, any score <60% was categorized as poor score, 60%-80% as average score and >80% as good score. Students showed poor knowledge and attitude towards COVID-19. But the practice of dental hygiene students towards COVID-19 was found to be good with the score of 83.4%.

CONCLUSION

The outcome of this cross-sectional study shows that most of dental hygiene students studying in Kingdom of Saudi Arabia are following good practices towards COVID-19 inspite of having poor knowledge and attitude.

Ocular manifestations of recent viral pandemics: A literature review

Viral pandemics often take the world by storm, urging the medical community to prioritize the most evident systemic manifestations, often causing ocular manifestations to go unnoticed. This literature review highlights the ocular complications of the Monkeypox, SARS-CoV-2, MERS, Ebola, H1N1, and Zika viruses as the most recent viral pandemics. Research into the effects of these pandemics began immediately. Moreover, it also discusses the ocular complications of the vaccines and treatments that were used in the scope of the viral pandemics. Additionally, this review discusses the role of the eye as an important route of viral transmission, and thereafter, the International recommendations to reduce the incidence of viral transmission were mentioned. Lastly, this paper wants to lay out a platform for researchers who want to learn more about how viruses show up in the eye.

Association of COVID-19 Infection With Wearing Glasses in a High-Prevalence Area in Denmark and Sweden

Importance

Observational studies have indicated that glasses might protect against contracting COVID-19 through reduced airborne and contact transmission.

Objective

To investigate the association between wearing one's own glasses with contracting COVID-19 when adjusting for relevant confounders.

Design, Setting, and Participants

This cohort study was conducted during the first wave of the COVID-19 pandemic (June to August 2020) in Denmark and Sweden, where personal protective equipment was not recommended for the general population at the time. Employees at Falck, an international rescue corps with different job functions (ambulance, health care, office, and field staff, firefighters, and roadside assistance) participated in the study.

Exposures

The main exposure was wearing glasses (also including contact lenses and reading glasses), which was assessed in a questionnaire. Persons wearing glasses were compared with those who did not wear glasses (ie, nonusers). To adjust for potential confounders, information on age, sex, job function, and number of workday contacts were included.

Main Outcomes and Measures

The outcome was COVID-19 infection before (positive polymerase chain reaction test) or during the study period (biweekly voluntary tests with a rapid test). The investigated hypothesis was formulated after collecting the data.

Results

A total of 1279 employees in Denmark and 841 in Sweden were included (839 [39.6%] female and 1281 [60.4%] male; 20.5% were aged <40 years; 57.0%, 40-60 years, and 22.5%, >60 years). Of these, 829 individuals (64.8%) in Denmark and 619 (73.6%) in Sweden wore glasses. Wearing glasses was inversely associated with COVID-19 infection in the Swedish cohort (odds ratio [OR], 0.61 [95% CI, 0.37-0.99]; P = .047; seroprevalence, 9.3%) but not in the Danish cohort (OR, 1.14 [95% CI, 0.53-2.45]; P = .73; seroprevalence, 2.4%). Adjusting for age, sex, job function, and number of workday contacts in Sweden, wearing glasses no longer was associated with COVID-19 infection (OR, 0.64 [95% CI, 0.37-1.11]; P = .11). When stratifying by job function, a large difference was observed among office staff (OR, 0.20 [95% CI, 0.06-0.70]; P = .01) but not ambulance staff (OR, 0.83 [95% CI, 0.41-1.67]; P = .60) nor health care staff (OR, 0.89 [95% CI, 0.35-2.30]; P = .81).

Conclusions and Relevance

While wearing one's glasses was inversely associated with COVID-19 in Sweden in an unadjusted analysis, an association no longer was identified when adjusting for confounders. These results provide inconclusive findings regarding whether wearing one's own glasses is associated with a decreased risk of COVID-19 infections.

Evaluation of the diagnosis and treatment options for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Viruses are non-living organisms that cause many problems for human societies annually. The outbreak of some dangerous viruses causing acute pneumonia has been the leading cause of death in the world. The epidemiological findings showed that the virus is developing different and dangerous species by creating new mutations, which makes it difficult to treat. The diagnosis and treatment of corona virus disease (COVID-19) has been one of the most important topics in the scientific community for the past 2 years. There are several diagnostic methods available for the detection of COVID-19 that are highly accurate and require less time. The use of some therapies such as remdesivir with basic therapy has shown high therapeutic effectiveness, but the therapeutic side effects such as decreased glomerular filtration rate, decreased lymphocyte count, respiratory failure, and increased blood creatinine levels in most treatments have been observed. The COVID-19 infection and the associated deaths are still very worrying, therefore, rapid diagnosis and timely management of this deadly infection and the necessary measures for eradicating COVID-19 are important.

Updates on Coronavirus-Related Ocular Manifestations: From the Past to COVID-19 Pandemic

Context: Coronaviruses are the largest RNA viruses associated with some ocular manifestations. There are various contradictory reports about the ocular manifestations of coronaviruses in humans. Different ocular tissues can affect coronavirus-associated infectious diseases. Evidence Acquisition: All manuscripts were collected from PubMed, Google Scholar, and other relevant databases. All searches were done by specific keywords, including "coronavirus," "ocular disease," and "eye." Results: There are various contradictory reports about the ocular effects of coronaviruses in humans. Different ocular tissues are involved in coronavirus-associated infectious diseases. The ductal connection between the upper respiratory tract and eye mucosa through the nasolacrimal duct can be an entrance to respiratory viruses, such as coronaviruses. The coronavirus can infect the retina, conjunctiva, cornea, and uvea of the eye. The primary SARS-CoV-2 receptor, ACE2, is mainly expressed in the posterior tissues of the eye, such as the retina and RPE. Feline CoV, SARS-CoV, MERS-CoV, and infectious bronchitis virus (IBV) are responsible for conjunctiva involvement in coronavirus-related ocular pathogenesis. Also, various studies are held on COVID-19 and the impact of the conjunctiva on diagnosis and medical complications. Given that the cornea has an acceptable expression of ACE2 and TMPRSS2 genes compared to lung tissue, some studies were done on the impact of the cornea in COVID-19. Feline infectious peritonitis virus (FIPV) is also related to uvea complications. The experiments of human and animal models on the effects of coronaviruses on the retina and cornea in the event of various epidemics of coronaviruses and new and unknown ocular complications can be of great help to future studies. Conclusions: Given the importance of investigating the pathogenesis and other routes of SARS-CoV-2 infection, especially in areas other than the respiratory tract, this report attempts to highlight the importance of eye infections caused by the virus, its role in maintaining the virus transmission chain, and its impact on public health.

Conjunctival Swab Findings in 484 COVID-19 Patients in Four Hospital Centers in Slovakia

Since 2020, the COVID-19 (Coronavirus Disease 2019) has quickly become a worldwide health problem. Ophthalmologists must deal with symptoms as well. For the positive detection in the conjunctival sac swab in COVID-19 patients hospitalized in Slovakia during March 2021 in four hospital centers, we used a test based on a polymerase chain reaction (PCR). In a group of 484 patients, 264 males (55%) and 220 females (45%) with clinical symptoms were identified with COVID-19 as a clinical diagnosis. The PCR test swab results from the conjunctival sac taken on the same day were positive in 58 patients (12%), 31 males (with a mean age of 74.6 ± 13.59 years) and 27 females (with a mean age of 70.63 ± 14.17 years); negative in 417 patients (86%); and 9 patients (2%) had an unclear result. The cycle threshold values comparing the nasopharynx and conjunctiva were also different in the group of all patients divided by age and gender. In COVID-19 patients the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was detectable using PCR test in the nasopharynx but also in the conjunctival sac swab, where the positivity rate was only 12%.

Conjunctival epithelial cells resist productive SARS-CoV-2 infection

Conjunctival epithelial cells, which express viral-entry receptors angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine type 2 (TMPRSS2), constitute the largest exposed epithelium of the ocular surface tissue and may represent a relevant viral-entry route. To address this question, we generated an organotypic air-liquid-interface model of conjunctival epithelium, composed of basal, suprabasal, and superficial epithelial cells, and fibroblasts, which could be maintained successfully up to day 75 of differentiation. Using single-cell RNA sequencing (RNA-seq), with complementary imaging and virological assays, we observed that while all conjunctival cell types were permissive to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome expression, a productive infection did not ensue. The early innate immune response to SARS-CoV-2 infection in conjunctival cells was characterised by a robust autocrine and paracrine NF-κB activity, without activation of antiviral interferon signalling. Collectively, these data enrich our understanding of SARS-CoV-2 infection at the human ocular surface, with potential implications for the design of preventive strategies and conjunctival transplantation.

DESIGN AND NUMERICAL ANALYSIS OF FACE MASK POLYMER SHIELD AGAINST INFECTIOUS DISEASES

Viruses that cause infections spread very quickly and has a fatal risk to people with chronic diseases. Since the virus vaccine and the drugs to be used in treatment are not fully developed, alternative ways to protect from the virus are being investigated. The Covid-19 virus has been recognized by the World Health Organization (WHO) as a pandemic. In this study, the effect of face mask shield against Covid-19 and other infections were investigated using finite element analysis (FEA). Three-dimensional model of the conventional face mask, equipment and shield was performed with the SolidWorks software. Computer-aided simulations were performed using AnsysWorkbench explicit dynamics module. The loading, boundary conditions and material properties were defined in the AnsysWorkbench. The effects of droplets formed because of cough or sneezing on the human model with mask and shield were analyzed. It has been confirmed from the analyzes that both the mask and the shield are effective against the virus.

Comparative Evaluation of Antimicrobial, Antiamoebic, and Antiviral Efficacy of Ophthalmic Formulations

The extensive use of ophthalmic antibiotics is contributing to the appearance of resistant bacterial strains, which require prolonged and massive treatments with consequent detrimental outcomes and adverse effects. In addition to these issues, antibiotics are not effective against parasites and viruses. In this context, antiseptics could be valuable alternatives. They have nonselective mechanisms of action preventing bacterial resistance and a broad spectrum of action and are also effective against parasites and viruses. Here, we compare the in vitro antibacterial, antiameobic, and antiviral activities of six ophthalmic formulations containing antiseptics such as povidone-iodine, chlorhexidine, and thymol against Gram-positive and Gram-negative bacteria, the amoeba Acanthamoeba castellanii, and two respiratory viruses, HAdV-2 and HCoV-OC43. The results suggest that, among all the tested formulations, Dropsept, consisting of Vitamin E TPGS-based (tocopheryl polyethylene glycol succinate) in combination with the antiseptic chlorhexidine, is the one with the highest range of activities, as it works efficiently against bacteria, amoeba, and viruses. On the other hand, the solution containing PVA (polyvinyl alcohol) and thymol showed a promising inhibitory effect on Pseudomonas aeruginosa, which causes severe keratitis. Given its high efficiency, Dropsept might represent a valuable alternative to the widely used antibiotics for the treatment of ocular infections. In addition to this commercial eye drop solution, thymol-based solutions might be enrolled for their natural antimicrobial and antiamoebic effect.

Long-Acting Protective Ocular Surface by Instilling Adhesive Dual-Antiviral Nanoparticles

The eye is susceptible to viral infections, causing severe ocular symptoms or even respiratory diseases. Methods capable of protecting the eye from external viral invasion in a long-term and highly effective way are urgently needed but have been proved to be extremely challenging. Here, a strategy of forming a long-acting protective ocular surface is described by instilling adhesive dual-antiviral nanoparticles. Taking pseudotyped severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a model virus, antiviral agent-loaded nanoparticles are coated with a "double-lock" hybrid cell membrane abundant with integrin-β1 and angiotensin converting enzyme II (ACE2). After instillation, the presence of integrin-β1 endows coated nanoparticles with steady adhesion via specific binding to Arg-Gly-Asp sequence on the fibronectin of ocular epithelium, achieving durable retention on the ocular surface. In addition to loaded inhibitors, the exposure of ACE2 can trap SARS-CoV-2 and subsequently neutralize the associated spike protein, playing a dual antiviral effect of the resulting nanoparticles. Adhesive dual-antiviral nanoparticles enabled by coating with a "double-lock" hybrid cell membrane could be a versatile platform for topical long-acting protection against viral infection of the eye.

Assessment of corneal endothelial cell morphology and anterior segment parameters in COVID-19

Background

The ocular manifestations of the 2019 novel coronavirus disease (COVID-19) vary from acute follicular, pseudomembranous, and hemorrhagic conjunctivitis to keratoconjunctivitis with subepithelial infiltrates and dendritic lesions. Similar to other respiratory viruses, such as adenoviruses, it is thought that COVID-19 may impact the cornea. However, its impact on the cornea and anterior segment parameters are currently poorly understood.

Objective

This study aims to assess the corneal endothelial cell morphology and anterior segment parameters in patients who have recovered from COVID-19.

Methods

In this cross-sectional study, the COVID-19 group comprised 34 patients who had been diagnosed with and recovered from COVID-19, while the control group comprised age- and sex-matched individuals without any systemic or ocular diseases. The endothelial cell density (ECD), coefficient of variation (CV) of cell area, hexagonal cell percentage (HEX), anterior chamber depth (ACD), central corneal thickness (CCT), horizontal anterior chamber diameter (HACD), iridocorneal angle (ICA), horizontal visible iris diameter (HVID), pupillary diameter (PD), and keratometry values (K1 and K2) were analyzed for each participant. The differences in each of these between the groups were analyzed using either an independent samples t test or a Mann-Whitney U test based on the normality of the data.

Results

Regarding corneal endothelial cell morphology, the ECDs for the COVID-19 and control groups were 2278.50 ± 186.78 cells/mm² and 2420.15 ± 222.25 cells/mm², respectively (p = 0.002). A significant increase was noted in CV values in the COVID-19 group compared with the control group (p < 0.001). The HEX values for the COVID-19 and control groups were 56.26 ± 5.75 and 61.50 ± 3.63, respectively (p < 0.001). Regarding the anterior segment parameters, no significant differences were observed between the groups (p > 0.05).

Conclusions

It was hypothesized that individuals who had recovered from COVID-19 would demonstrate a reduction in their endothelial functional preserves. A decrease in ECD and HEX and an increase in CV were observed in the individuals during their early post-recovery period from COVID-19.

Evaluating Ocular Symptoms and Tear Film Cytokine Profiles in Symptomatic COVID-19 Patients

Background: This study investigated the presence and duration of ophthalmic symptoms in the early phase of COVID-19 to assess the corresponding local immune response on the ocular surface. Methods: The study included data from 180 COVID-19 patients and 160 age-matched healthy controls. The main finding was the occurrence of ophthalmological manifestations at the time of admission to the hospital and during the preceding 7 days. Tear film concentrations of TNF-α, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12 p70, GM-CSF, and IFN-γ were determined by a magnetic bead assay. Results: Among the COVID-19 patients, 12.64% had at least one ocular symptom at the time of admission, and 24.14% had symptoms within the preceding 7 days (p < 0.001 vs. controls). We found that the COVID-19 patients complained more frequently about eye tearing (p = 0.04) and eye pain (p = 0.01) than controls. A multivariate analysis of the patients and controls adjusted for age and sex revealed that COVID-19 was an independent factor associated with higher VEGF and IL-10 tear film concentrations (β = +0.13, p = 0.047 and β = +0.34, p < 0.001, respectively) and lower IL-1β, IL-8, and GM-CSF levels (β = −0.25, p < 0.001; β = −0.18, p = 0.004; and β = −0.82, p = 0.0 respectively). Conclusions: SARS-CoV-2 does not attract a strong local response of the conjunctival immune system; therefore, ophthalmic symptoms may not constitute a substantial element in the clinical picture of novel COVID-19 infection.

A Retrospective Study of Oral Emergency Services During COVID-19

OBJECTIVES

This study was performed to examine changes in the number of patient visits and types of oral services in an oral emergency department from the beginning to the control stage of the coronavirus disease 2019 (COVID-19) outbreak in Beijing.

METHODS

The numbers of daily oral emergency visits from January 20 to March 24, 2020, at a dental university hospital in Beijing and daily newly confirmed COVID-19 cases in Beijing during the same period were collected and analysed. All oral emergency patient information (including sex, age, and oral diagnosis) was also collected and analysed. Patients with incomplete medical data were excluded.

RESULTS

In total, 12,416 patients were included in this study. The number of daily emergency visits was negatively correlated with the number of newly confirmed local COVID-19 cases in Beijing (P < .001). The number of daily emergency visits during the COVID-19 stable period in Beijing was greater than that during the outbreak period (P < .001). Compared to those in the COVID-19 outbreak period, the percentages of females, children and adolescents, patients with acute toothache, and patients with nonurgent cases were higher in the stable period, and the numbers of patients with toothache, trauma, infection, and nonemergency conditions increased in the COVID-19 stable period (P < .001).

CONCLUSIONS

COVID-19 significantly influenced the number of patient visits and the percentages of patients with oral emergency situations in the oral emergency department. There were obvious differences in treatment seeking for oral emergencies between the COVID-19 periods in Beijing. There was an inverse relationship between daily oral emergency visits and daily confirmed COVID-19 cases in Beijing.

COVID-19 Pandemic Impact on Dental Practice

Introduction: The COVID-19 pandemic has had a huge impact on the dentistry industry from the initial lockdown in March 2020 to the present day, nearly one year later with dentists unable to practice during the initial lockdown, that is when revenue took the biggest hit. The study aims to examine the impact of COVID-19 on dental practices during the pandemic in Bulgaria. Material and methods: A specially developed questionnaire was distributed electronically among 138 dentists from all regions of Bulgaria. The collected primary statistical information was entered and processed with the statistical package SPSS Statistics 19.0 Results: Statistical analyzes of the questionnaire show that (62,32%±4,12) of dentists say COVID-19 made no impact on their decision to retire or continue practicing; 43% of respondents predict revenue or costs will be the biggest challenge facing their practice in 2021. Part of dentists (34.78 % ± 4,05) believe that COVID-19 allowed them to learn more about infection control. Most of the respondents (87.68% ± 2.79) agree their income was lower in April to September of 2020 compared to 2019. More than half of dentists (61.59 % ± 4.14) believe Covid 19 has not impacted the products or services they offer. The majority of the participants (84.78 % ± 3.05) did not perform non-emergency procedures during the pandemic. Conclusion: Despite the numerous disadvantages caused by the COVID-19 pandemic, our survey shows dentists have found ways to adapt and succeed. Introduction: The COVID-19 pandemic has had a huge impact on the dentistry industry from the initial lockdown in March 2020 to the present day, nearly one year later with dentists unable to practice during the initial lockdown, that is when revenue took the biggest hit. The study aims to examine the impact of COVID-19 on dental practices during the pandemic in Bulgaria. Material and methods: A specially developed questionnaire was distributed electronically among 138 dentists from all regions of Bulgaria. The collected primary statistical information was entered and processed with the statistical package SPSS Statistics 19.0 Results: Statistical analyzes of the questionnaire show that (62,32%±4,12) of dentists say COVID-19 made no impact on their decision to retire or continue practicing; 43% of respondents predict revenue or costs will be the biggest challenge facing their practice in 2021. Part of dentists (34.78 % ± 4,05) believe that COVID-19 allowed them to learn more about infection control. Most of the respondents (87.68% ± 2.79) agree their income was lower in April to September of 2020 compared to 2019. More than half of dentists (61.59 % ± 4.14) believe Covid 19 has not impacted the products or services they offer. The majority of the participants (84.78 % ± 3.05) did not perform non-emergency procedures during the pandemic. Conclusion: Despite the numerous disadvantages caused by the COVID-19 pandemic, our survey shows dentists have found ways to adapt and succeed.

Orthodontic Adolescent Patients’ Attitudes toward Protective Face Mask Wearing during the COVID-19 Pandemic

Background and Objectives: The COVID-19 pandemic led to restrictive measures, which aimed to limit the spread of the SARS-CoV-2 virus. These restrictions impacted all areas of life, including the activity of dental offices. For patients with orthodontic appliances, closing the dental offices was a major issue, as most orthodontic treatments last for more than a year and require regular checkups. The aim of this research was to assess the impact that the restrictive measures that were imposed during the COVID-19 pandemic, and, especially, wearing a face mask had on a sample of Romanian teenagers undergoing fixed orthodontic treatment. Material and Methods: The study group consisted of 277 orthodontic patients, with ages between 12 and 17.9 years, from North-Western Romania. They completed a 9-item questionnaire. The control group consisted of 231 participants, with ages between 12 and 17.9 years. They completed an 8-item questionnaire. Results: Most patients from the study group were not worried that wearing a protective face mask would hide their braces (never—49.5%; rarely—26.7%), and their desire to undergo an orthodontic treatment was not affected by the compulsoriness of face mask wearing (never—51.6%; rarely—26%). In contrast to that, in the control group, more than 50% of the participants were worried to some degree that wearing a protective face mask would hide their smile (occasionally—29.9%; frequently—18.2%; very frequently—2.2%). The majority of the participants from the study group did not consider interrupting the orthodontic treatment due to the COVID-19 pandemic (62.5%), and the majority of the participants from the control group did not consider not going to the dentist due to the COVID-19 pandemic (70.6%). Most of the participants from the study group were not happy that they had to wear a face mask, which covered their orthodontic appliances, during the orthodontic treatment (68.6%). The attitude was similar to that of the participants from the control group, who were not happy that they had to wear a face mask, that covered their smile (51.1%). In the study group, most patients did not want face mask wearing to continue to be compulsory, given the fact that their orthodontic appliances were no longer visible (52%). In the control group, the attitude was similar, with 48.1% of the participants not wanting face mask compulsoriness to be maintained. Conclusions: In conclusion, although, most patients would not like to continue wearing a face mask as a mandatory regulation, they were not concerned or negatively affected by wearing a protective face mask, even though face masks hid their braces.

[Hypochlorous acid as an antiseptic in the care of patients with suspected COVID-19 infection]

PURPOSE

The SARS-CoV-2 virus, which causes COVID-19 disease, is transmitted by aerosols or by contact with infected surfaces. The route of entry to the body is through the nasal, oral or conjunctival mucosa. Health workers must use effective protection measures against the entry of the virus into mucous membranes, both physical and antiseptic filters. There is an antiseptic used in Ophthalmology that we believe could have virucidal action against the SARS-CoV-2 virus, formulated based on 0.01% hypochlorous acid.

METHODS

An exhaustive search has been carried out in the databases of Pubmed and Web of Science to identify relevant articles on the virucidal activity of hypochlorous acid in different concentrations until October 4, 2020.

RESULTS

There is evidence of the virucidal efficacy of 0.01% hypochlorous acid against SARS-CoV-2. According to the different scientific publications reviewed, hypochlorous acid has virucidal efficacy against different viruses, among them, SARS-CoV-2.

CONCLUSIONS

The 0.01% hypochlorous acid could act as an effective antiseptic against SARS-CoV-2, exerting a barrier on the mucosa to prevent COVID-19 infection. It can be used on the eyes, nose and mouth. We consider it necessary to assess its use in the protocol for patient health care in ophthalmology consultations, as well as to recommend its use to the general population to reduce viral load and / or prevent transmission of infection. Additional in vivo studies would be required to confirm its antiseptic action.

Risk and Impact of Severe Acute Respiratory Syndrome Coronavirus 2 Infection on Corneal Transplantation: A Case-Control Study

PURPOSE

The purpose of this study was to evaluate the risk of symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection after corneal transplantation surgery, with cataract surgeries as controls, and the impact of the novel coronavirus disease pandemic in the clinical and surgical complications of corneal transplantation and cataract surgeries.

METHODS

A retrospective matched case-control study of 480 consecutive individuals who underwent surgery at the Bascom Palmer Eye Institute between May 2020 and November 2020. A total of 240 patients who underwent corneal transplantation with tissue obtained from the Florida Lions Eye Bank were age, race, ethnicity, and sex matched with 240 patients who underwent cataract surgery during the same day and by the same surgical team. Only the first corneal transplant or cataract surgery during this period was considered for each individual. All donors and recipients were deemed SARS-CoV-2 negative by a nasopharyngeal polymerase chain reaction test before surgery. Postoperative SARS-CoV-2 infections were defined as previously SARS-CoV-2(-) individuals who developed symptoms or had a positive SARS-CoV-2 polymerase chain reaction test during the first postoperative month.

RESULTS

Mean age, sex, race, and ethnicity were similar between groups. There were no differences between the corneal transplant and cataract groups in the rates of SARS-CoV-2 infection before (5.8% vs. 7.5%, P= 0.6) or after surgery (2.9% vs. 2.9%, P = 1). The rates of postoperative complications did not increase during the pandemic, compared with previously reported ranges.

CONCLUSIONS

In this study, postoperative SARS-CoV-2 infection was similar for individuals undergoing corneal transplantation or cataract surgery. Further research is required to evaluate the transmission of SARS-CoV-2 through corneal tissue.

Hypochlorous acid as an antiseptic in the care of patients with suspected COVID-19 infection

Purpose

The SARS-CoV-2 virus, which causes COVID-19 disease, is transmitted by aerosols or by contact with infected surfaces. The route of entry to the body is through the nasal, oral or conjunctival mucosa. Health workers must use effective protection measures against the entry of the virus into mucous membranes, both physical and antiseptic filters. There is an antiseptic used in Ophthalmology that we believe could have virucidal action against the SARS-CoV-2 virus, formulated based on 0.01% hypochlorous acid.

Methods

An exhaustive search has been carried out in the databases of Pubmed and Web of Science to identify relevant articles on the virucidal activity of hypochlorous acid in different concentrations until October 4, 2020.

Results

There is evidence of the virucidal efficacy of 0.01% hypochlorous acid against SARS-CoV-2. According to the different scientific publications reviewed, hypochlorous acid has virucidal efficacy against different viruses, among them, SARS-CoV-2.

Conclusions

The 0.01% hypochlorous acid could act as an effective antiseptic against SARS-CoV-2, exerting a barrier on the mucosa to prevent COVID-19 infection. It can be used on the eyes, nose and mouth. We consider it necessary to assess its use in the protocol for patient health care in ophthalmology consultations, as well as to recommend its use to the general population to reduce viral load and/or prevent transmission of infection. Additional in vivo studies would be required to confirm its antiseptic action.

Ocular transmissibility of COVID-19: possibilities and perspectives

Since the initial outbreak of coronavirus disease 2019 (COVID-19), extensive research has emerged from across the globe to understand the pathophysiology of this novel coronavirus. Transmission of this virus is a subject of particular interest as researchers work to understand which protective and preventative measures are most effective. Despite the well understood model of aerosol-respiratory mediated transmission, the exact mechanism underlying the inoculation, infection and spread of COVID-19 is currently unknown. Given anatomical positioning and near constant exposure to aerosolized pathogens, the eye may be a possible gateway for COVID-19 infection. This critical review explores the possibility of an ocular-systemic or ocular-nasal-pulmonic pathway of COVID-19 infection and includes novel insights into the possible immunological mechanisms leading to cytokine surge.

Transient myopia due to choroidal effusion: A novel ocular complication of COVID-19 infection

COVID-19 was declared as a global pandemic by the WHO in 2020. Although it is a respiratory virus, ocular complications and manifestations of the infection have been reported in different forms. We report a case of transient myopia and narrow angles due to choroidal effusion following infection by the SARS-COV-2 virus. We propose that the ability of the virus to incite an inflammatory response in the host body may be the mechanism behind the disease entity. This is a novel, previously undocumented ocular complication in case of a COVID-19 infection.

SARS-CoV-2 and its beta variant of concern infect human conjunctival epithelial cells and induce differential antiviral innate immune response

PURPOSE

SARS-CoV-2 RNA has been detected in ocular tissues, but their susceptibility to SARS-CoV-2 infection is unclear. Here, we tested whether SARS-CoV-2 can infect human conjunctival epithelial cells (hCECs) and induce innate immune response.

METHODS

Conjunctival tissue from COVID-19 donors was used to detect SARS-CoV-2 spike and envelope proteins. Primary hCECs isolated from cadaver eyes were infected with the parental SARS-CoV-2 and its beta variant of concern (VOC). Viral genome copy number, and expression of viral entry receptors, TLRs, interferons, and innate immune response genes were determined by qPCR. Viral entry receptors were examined in hCECs and tissue sections by immunostaining. Spike protein was detected in the cell culture supernatant by dot blot.

RESULTS

Spike and envelope proteins were found in conjunctiva from COVID-19 patients. SARS-CoV-2 infected hCECs showed high viral copy numbers at 24-72h post-infection; spike protein levels were the highest at 24hpi. Viral entry receptors ACE2, TMPRSS2, CD147, Axl, and NRP1 were detected in conjunctival tissue and hCECs. SARS-CoV-2 infection-induced receptor gene expression peaked at early time points post-infection, but gene expression of most TLRs peaked at 48 or 72hpi. SARS-CoV-2 infected hCECs showed higher expression of genes regulating antiviral response, RIG-I, interferons (α, β, & λ), ISG15 & OAS2, cytokines (IL6, IL1β, TNFα), and chemokines (CXCL10, CCL5). Compared to the parental strain, beta VOC induced increased viral copy number and innate response in hCECs.

CONCLUSIONS

Conjunctival epithelial cells are susceptible to SARS-CoV-2 infection. Beta VOC is more infectious than the parental strain and evokes a higher antiviral and inflammatory response.

SARS-CoV-2 in the Environment: Its Transmission, Mitigation, and Prospective Strategies of Safety and Sustainability

The emergence and spread of SARS-CoV-2 have threatened the world’s public health security. The COVID-19 pandemic has affected many countries and significantly smashed the global economy, and also affected the health of the environment. This has upraised many apprehensions about its high transmission rate. Even though the most important routes of its transmission include direct contact and respiratory droplets, the infection through non-direct contacts also plays an important role. The increasing demand for intensive healthcare, escalating death toll and disruption in supply chains and trade have directed to mass implementation of testing, quarantine, and lockdown to restrain virus transmission. The lockdown has been a boon and a bane as well when it comes to the health of the environment. It had improved the air and water quality since the industrial activities were banned and therefore there was no addition of pollutants in the environment, but the usage of plastic-based personal protective equipment (PPE) and other medical waste has simultaneously resulted in huge plastic pollution that is choking seas and marine lives. The precautionary measures given by the United Nations Environment Programme in its COVID response factsheets suggest ways to reduce medical waste and to prevent the spread of the present pandemic. The recent green innovations and environmental stringency programs have resulted in reducing the threats to the environment that would eventually help in inhibiting the spread of such pandemics. In addition, proper measures should be adopted to safeguard the complete health of humans and the environment to execute safety and sustainable development that will help in achieving a stable biome.

An Ophthalmologist's Insight Into The Viral Pandemics

In recent past, major pandemics and epidemics have occurred due to the emergence and resurgence of the novel strains of viruses like Influenza [HINI-A "Spanish Flu", H1N1-Novel A "Swine flu"], Corona [Middle East Respiratory Syndrome (MERS), Severe acute respiratory syndrome (SARS-CoV-1, SARS-CoV-2)] and Ebola virus [Ebola virus disease]. These infectious diseases may have several ocular manifestations and rarely might be the presenting symptom of the underlying disease. The eyes can act as a portal of entry and/or route of viral transmission for these pathogens. Therefore, an ophthalmologist/optometrist needs to act with ample preparedness and responsibility. Establishing a standard of care in ophthalmic practice by modifying the conventional examination techniques and adopting tele-ophthalmology model to triage the patients can control the community spread of the disease. This article aims to elucidate the ocular manifestations in these pandemics and measures that should be adopted in ophthalmic practice to prevent the disease transmission.

Thermosensitive Poly(DHSe/PEG/PPG Urethane)-Based Hydrogel Extended Remdesivir Application in Ophthalmic Medication

The spread of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the coronavirus disease 2019 (COVID-19) outbreak beginning in March 2020. Currently, there is a lack of suitable dose formulations that interrupt novel coronavirus transmission via corneal and conjunctival routes. In the present study, we developed and evaluated a thermosensitive gelling system based on a selenium-containing polymer for topical ocular continuous drug release. In detail, di-(1-hydroxylundecyl) selenide (DHSe), poly(ethylene glycol) (PEG), and poly(propylene glycol) (PPG) were polymerized to form poly(DHSe/PEG/PPG urethane). The polymer was used to carry poorly water-soluble remdesivir (RDV) at room temperature to form the final thermosensitive in situ gel, which exhibited a typical sol-gel transition at 35 °C. The formed polymer was further characterized by rheology, thermology, and scanning electron microscopy. In vitro release studies and in vivo retention and penetration tests indicated that the thermogel provided the prolonged release of RDV. The RDV-loaded in situ gel was proven to be non-biotoxic against human corneal epithelial cells, with good ocular tolerance and biocompatibility in rabbit eyes.