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

Comparison of operating room nurses' satisfaction and preferences in using personal protective equipment for eye protection in the COVID-19 pandemic

Objectives. This study aimed to compare the problems, satisfaction and preferences of operating room nurses about the use of personal protective equipment (PPE) for eye protection during operations in the COVID-19 pandemic. Methods. This prospective quasi-experimental study was conducted in April 2021 in the operating room of a hospital in Turkey. The sample of this study consisted of 35 nurses who met the inclusion criteria. The evaluation of three types of eye protection equipment (goggles, goggle-type face shield and face shield) was repeated in the same group on consecutive days. Results. The comparison of the problems related to the use of PPE indicated that the highest rate of fogging (91.4%) was observed in goggles (p < 0.001), and skin injuries (28.6%) were experienced in goggles and face shields (p = 0.002). It was observed that operating room nurses were most satisfied (7.2 ± 1.4) with goggle-type face shields and ranked them in first place (80%) (p < 0.001). Conclusion. According to the results of this research, it was found that the PPE for eye protection that was the least problematic, provided the most satisfaction and was ranked in first place during the pandemic was the goggle-type face shield.

Changing face of non-infectious pediatric uveitis in the pre-pandemic and pandemic periods: a comparison study

OBJECTIVE

Our aim in this study was to reveal the clinical features of pediatric uveitis in the pandemic period and to compare it with the pre-pandemic era.

METHODS

This retrospective study included 187 children diagnosed with uveitis between the 11^th of March 2017 and the 11^th of March 2022. The patients were divided into two groups based on the date of diagnosis as follows; Group 1: Patients diagnosed in the pre-pandemic period (11^th March 2017-11^th March 2020); Group 2: Patients diagnosed in the pandemic period (12^th March 2020-11^th March 2022). Demographic data, characteristics of uveitis, underlying diseases, systemic treatment modalities, and complications were compared between the two groups.

RESULTS

A total of 187 (pre-pandemic 71, and pandemic 114) pediatric uveitis patients were recruited to the study. Fifty one percent (51%) of the patients were female. The number of patients diagnosed with uveitis increased approximately twice during the pandemic period compared to the pre-pandemic period. The frequency of anterior uveitis was found to be significantly higher in the pandemic period than in the pre-pandemic period (p = 0.037). It was mostly presented as symptomatic uveitis. There was a decrease in the diagnosis of JIA-related uveitis. ANA positivity increased in the pandemic period (p = 0.029). The response to treatment was better and the complication rate decreased in the pandemic period.

CONCLUSION

The present study involved a large number of pediatric patients with uveitis. There are some differences in the characteristics of pediatric uveitis cases comparing the pandemic period and the pre-pandemic period. This increased frequency and changing clinical features of pediatric uveitis seems to be a result of COVID-19 infection.

The Latest Cellular and Molecular Mechanisms of COVID-19 on Non-Lung Organs

Understanding the transmission pathways of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will aid in developing effective therapies directed at the virus’s life cycle or its side effects. While severe respiratory distress is the most common symptom of a coronavirus 2019 (COVID-19) infection, the virus is also known to cause damage to almost every major organ and system in the body. However, it is not obvious whether pathological changes in extra-respiratory organs are caused by direct infection, indirect, or combination of these effects. In this narrative review, we first elaborate on the characteristics of SARS-CoV-2, followed by the mechanisms of this virus on various organs such as brain, eye, and olfactory nerve and different systems such as the endocrine and gastrointestinal systems.

COVID-19 and ocular complications: A review of ocular manifestations, diagnostic tools, and prevention strategies

Background

The novel severe acute respiratory syndrome coronavins 2 (SARS-CoV-2) led to the severe Corona Virus Disease 2019 (COVID-19) outbreak that started in December 2019 in China and caused enormous health and economic problems worldwide. Over time, SARS-CoV-2 has demonstrated the capacity for mutation. As the most prevalent new coronavirus variety worldwide, the Omicron variant has supplanted the Delta variant. The COVID-19 primarily damages the immune system and the lungs, but it can also harm other organs secondarily, depending on the patients' co-existing conditions.

Main Text

COVID-19 is associated with ophthalmic manifestations such as conjunctival congestion, tear overflow, and conjunctival edema, with the majority of eye complications occurring in patients with severe infection. The virus may make a patient more susceptible to thrombotic conditions that affect venous and arterial circulation. Meanwhile, it can lead to efferent complications and mucormycosis which is more common in patients with diabetes or who have critical or severe SARS-CoV-2 infection. Significantly, there are a number of ocular side effects following the COVID-19 vaccination, such as herpetic keratitis and facial nerve palsy, which have been reported. These side effects may be caused by the vaccinations' propensity to trigger autoimmune symptoms or thromboembolic events. At present, large-scale nucleic acid testing mainly relies on nasopharyngeal swabs and throat swabs. Tear samples and conjunctival swabs may be helpful samples for the diagnosis of ocular SARS-CoV-2 infection. The eye could be a new route of infection, and finding ways such as effective environmental disinfection, scientific administrative control management, qualified personal protection and other measures to protect the eyes could further reduce the risk of infection.

Conclusions

This review aims to sum up the ocular complications of COVID-19, the possible pathogenesis, and preventive strategies to protect ophthalmology practitioners and patients by reviewing the currently available literature on the topic.

Retinal Findings in Hospitalized COVID-19 Patients, Is Routine Ophthalmological Examination Required after Discharge? Prospective Case-Control Study

OBJECTIVES

To investigate retinal findings by comparing patients hospitalized for COVID-19 with the control group.

METHODS

In this prospective study, 188 eyes of 94 recovered COVID-19 patients and 108 eyes of 54 healthy participants as a control group were evaluated. Patients were divided into three groups, those with mild, moderate, and severe COVID-19. Refractometry, tonometry, optical biometry, optical coherence tomography (OCT) measurements, and complete ophthalmological examinations were performed on healthy volunteers and COVID-19 patients on average 2 weeks after discharge. Pulse O₂ and vital parameters were also assessed. Primary outcomes were evaluated, such as retinal findings, and secondary outcomes as retinal thickness, choroidal thickness (CT), retinal nerve fiber layer thickness, and ganglion cell layer thickness.

RESULTS

There was no difference between the groups in terms of demographic data, ocular biometry, and intraocular pressure (p > 0.05). Pulse O₂ was lower in the study group (p < 0.001). Retinal findings were detected in 68 (36.1%) of 188 eyes in the study group and 28 (25.9%) of 108 eyes in the control group (p = 0.07). The two most common retinal findings were hypertensive retinopathy and retinal pigment epithelium alterations and/or drusen in both groups. In OCT measurements, significant thinning was observed in nasal macular thickness and superior 2 mm CT in the study group compared to the control group (p < 0.05). In patients divided into subgroups according to disease severity, no significant difference was found between the groups in any OCT parameter (p > 0.05).

CONCLUSION

It has been observed that COVID-19 infection does not cause a specific and sensitive finding in the ocular tissues, especially the retina, and does not produce a reproducible measurement result. Recommending routine eye exam after COVID-19 does not seem cost-effective.

Non-pulmonary involvement in COVID-19: A systemic disease rather than a pure respiratory infection

During the early phase of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), diagnosis was difficult due to the diversity in symptoms and imaging findings and the variability of disease presentation. Pulmonary manifestations are reportedly the main clinical presentations of COVID-19 patients. Scientists are working hard on a myriad of clinical, epidemiological, and biological aspects to better understand SARS-CoV-2 infection, aiming to mitigate the ongoing disaster. Many reports have documented the involvement of various body systems and organs apart from the respiratory tract including the gastrointestinal, liver, immune system, renal, and neurological systems. Such involvement will result in diverse presentations related to effects on these systems. Other presentations such as coagulation defects and cutaneous manifestation may also occur. Patients with specific comorbidities including obesity, diabetes, and hypertension have increased morbidity and mortality risks with COVID-19.

Detection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) RNA in the Human Eye

PURPOSE

To determine the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in postmortem ocular specimens of patients with severe COVID-19 disease.

PATIENTS AND METHODS

Postmortem conjunctival (28 samples), aqueous humor (30 samples) and vitreous humor (30 samples) specimens were obtained bilaterally from the eyes of 15 deceased COVID-19 patients within one hour of death. The presence of viral RNA was evaluated in samples using Real-time reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Positive RT-PCR SARS-COV-2 results were found in one conjunctival and 2 vitreous humor samples. All aqueous humor samples tested negative for the presence of SARS-COV-2 RNA. Of note, three positive samples were obtained from three different patients. The overall prevalence of positive RT-PCR ocular samples was 3.4% among all samples and 20% at the patient level.

CONCLUSION

SARS-CoV-2 RNA is detectable in postmortem conjunctival and vitreous humor samples of patients with severe COVID-19.

Ophthalmological Findings in Patients with SARS-CoV-2 Infection Examined at the National Institute of Infectious Diseases - INI/Fiocruz

PURPOSE

To describe the clinical characteristics, severity, and ophthalmological changes in SARS-CoV-2 patients through ophthalmological examinations performed at the reference center of the National Institute of Infectious Diseases, Brazil.

METHODS

This cross-sectional study assessed the examination results of SARS-CoV-2 patients from July 2020 to November 2020. In total, 150 patients were included and allocated into three groups of 50 patients depending on the disease severity. Group 1 patients were in the intensive care unit (ICU), group 2 patients were in the semi-ICU, and group 3 patients were outpatients.

RESULTS

Ten (6.7%) patients exhibited ophthalmological changes; five (10%), four (8%), and one (2%) patients in groups 1, 2, and 3, respectively. Ophthalmological findings included candle flame hemorrhage and cotton wool exudates. We analyzed the general characteristics of the 10 patients with ophthalmological changes. Nine were hospitalized and one was seen on an outpatient basis.

CONCLUSION

We observed ophthalmic changes in patients with SARS-CoV-2 infection, despite the absence of any clinical or laboratory risk factors indicative of such changes.

Bilateral anterior ischemic optic neuropathy and choroidal ischemia in a patient with COVID-19 infection

A 57-year-old male known case of diabetes mellitus presented with gradually bilateral decreased vision accompanied by ocular pain two weeks after diagnosis of SARS-CoV-2 infection. The results of examination and imaging were indicative of bilateral anterior ischemic optic neuropathy (AION) and massive choroidal ischemia, which may be associated with SARS-CoV-2-induced damages, including endothelial damage, hypercoagulable state, and hypoxia.

Covid-19 and its relation to the human eye: transmission, infection, and ocular manifestations

BACKGROUND

The world is suffering from a new strain of the coronavirus family-Covid-19. This virus strain affected different organs in the human body with a wide range of mild symptoms and moderate signs to severe and deadly ones. Multiple organs can be infected, and one of these organs is the eye. The eye is a vital organ that consists of vascular tissues and is connected to the respiratory tract through the tears and the nasolacrimal duct.

METHODS

Recent papers and research from PubMed, Researchgate, and Google Scholar were cited and thoroughly discussed. These papers were chosen based on their relevancy, reliability, publication year, published journal, and ease of accessibility to the paper itself.

RESULTS

The theory concluded that the ocular surface might consider a pathway for the virus attack and infection causation through the tears and the angiotensin-converting enzyme 2 located in the eye. This article thoroughly reviewed the history, the existing aspects of Covid-19, the ocular system features, and the claims about the possible involvement of the eye in the virus transmission along with the eye infection. There was no consensus on the eye's involvement theory.

CONCLUSION

The authors highlighted the extra work and research needed to be conducted to prove or deny these claims to provide a better understanding of the immune response of the eye to Covid-19 infection.

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.

One-Year Changes in Optic Nerve Head Parameters in Recovered COVID-19 Patients

BACKGROUND

The main purpose was to evaluate the changes in peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) in post-COVID-19 patients during 12-month follow-up.

METHODS

In this prospective study, patients with COVID-19 who were attended in the Hospital Clinico San Carlos (Madrid, Spain) were included. All patients underwent a complete ophthalmological examination, optic nerve head optical coherence tomography (OCT), and OCT angiography (OCTA) using the Cirrus HD-OCT 5,000 with AngioPlex OCTA 1, 3, and 12 months after laboratory-confirmed diagnosis. Sociodemographic data, medical history, disease severity, and laboratory workup were registered.

RESULTS

A total of 180 eyes of 90 patients with SARS-CoV-2 infection were included; the mean age was 55.5 ± 8.9 years, and 46 patients (51%) were females. The mean visual acuity was 0.76 ± 0.16, and no abnormalities attributable to SARS-CoV-2 were detected in the ocular or fundus examination. No differences in the OCT and OCTA data were found between severity groups in each visit (all P > 0.05). Overall, there was a decrease in RNFL global thickness ( P < 0.001) from the first to the last visit, and an increase in VD and flux index was noted in some sectors at the 12-month examination. A significant correlation was detected at 12 months between vascularization parameters and RNFL thickness.

CONCLUSIONS

One year after SARS-CoV-2 infection, changes in peripapillary RNFL thickness and vascularization occur, possibly indicating a recovery in such parameters.

Evaluation of retinal and choroidal parameters as neurodegeneration biomarkers in patients with post-covid-19 syndrome

BACKGROUND

To investigate the neurodegenerative effects of post-COVID-19 syndrome.

METHODS

This comparative, cross-sectional study included patients who had post-COVID-19 prolonged neurologic symptoms. The control group was selected from volunteer participants with similar age, sex, and spherical equivalent characteristics. After detailed ophthalmic examinations, spectral-domain optic coherence tomography (SD-OCT) analysis of the macula and peripapillary retinal nerve fiber layer (m-RNFL, p-RNFL respectively) were obtained. We also evaluated the choroidal parameters with the ImageJ software. Post-COVID-19 symptoms and disease severity of the patients were also questioned.

RESULTS

Thirty-four eyes of 20 patients, and 39 eyes of 23 healthy individuals were included in the study. Thinning was found in the inner superior quadrant of mRNFL (p < 0.05). More prominent and common thinning of retinal layers was observed in the ganglion cell layer (GCL) and inner plexiform layer (IPL) segments in the patient group. There was no difference between the groups in the calculated choroidal parameters (p > 0.05). In the regression models created, lung involvement was the most prominent parameter associated with thinning of the OCT layers. The other factors were male sex, and the presence of loss of taste and smell also led to deterioration in some parameters.

CONCLUSIONS

We detected an overall thinning of the GCL and IPL layers with no significant change in CMT, pRNFL, and CVI in the post-COVID-19 period, indicating the direct or indirect effect of SARS-CoV-2 on these layers, rather than a long-term neurodegenerative effect.

Eyelid Myokymia—a Presumed Manifestation of Coronavirus Disease 2019 (COVID-19)

The purpose of this study is to report eyelid myokymia in patients recently recovered from COVID-19 disease. A cohort of 15 patients who developed eyelid myokymia during or immediate post-recovery of systemic disease were evaluated. Demographic, clinical characteristics, effect of age, and hospitalization on the disease course were studied. The disease course was evaluated every month for 3 months period. All, except 2, patients had complete resolution of lid myokymia within 3 months of onset. Median [IQR] myokymia recovery time was 42 [31,60] days. Age and duration of hospitalization had a significant linear relationship with myokymia recovery time. Recovery was delayed by 2.64 days with every 1-year increment in age and by 6.19 days with every additional day of hospital stay. Recovery time was independent of severity of systemic disease (P = .055) and gender (P = 0.2). Eyelid myokymia can be a possible manifestation of COVID-19 recovery phase. While myokymia recovers gradually in all these patients, older age and a longer duration of hospitalization are associated with slower recovery.

Nanomaterials to combat SARS-CoV-2: Strategies to prevent, diagnose and treat COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the associated coronavirus disease 2019 (COVID-19), which severely affect the respiratory system and several organs and tissues, and may lead to death, have shown how science can respond when challenged by a global emergency, offering as a response a myriad of rapid technological developments. Development of vaccines at lightning speed is one of them. SARS-CoV-2 outbreaks have stressed healthcare systems, questioning patients care by using standard non-adapted therapies and diagnostic tools. In this scenario, nanotechnology has offered new tools, techniques and opportunities for prevention, for rapid, accurate and sensitive diagnosis and treatment of COVID-19. In this review, we focus on the nanotechnological applications and nano-based materials (i.e., personal protective equipment) to combat SARS-CoV-2 transmission, infection, organ damage and for the development of new tools for virosurveillance, diagnose and immune protection by mRNA and other nano-based vaccines. All the nano-based developed tools have allowed a historical, unprecedented, real time epidemiological surveillance and diagnosis of SARS-CoV-2 infection, at community and international levels. The nano-based technology has help to predict and detect how this Sarbecovirus is mutating and the severity of the associated COVID-19 disease, thereby assisting the administration and public health services to make decisions and measures for preparedness against the emerging variants of SARS-CoV-2 and severe or lethal COVID-19.

Targeting the Complement-Sphingolipid System in COVID-19 and Gaucher Diseases: Evidence for a New Treatment Strategy

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2)-induced disease (COVID-19) and Gaucher disease (GD) exhibit upregulation of complement 5a (C5a) and its C5aR1 receptor, and excess synthesis of glycosphingolipids that lead to increased infiltration and activation of innate and adaptive immune cells, resulting in massive generation of pro-inflammatory cytokines, chemokines and growth factors. This C5a-C5aR1-glycosphingolipid pathway- induced pro-inflammatory environment causes the tissue damage in COVID-19 and GD. Strikingly, pharmaceutically targeting the C5a-C5aR1 axis or the glycosphingolipid synthesis pathway led to a reduction in glycosphingolipid synthesis and innate and adaptive immune inflammation, and protection from the tissue destruction in both COVID-19 and GD. These results reveal a common involvement of the complement and glycosphingolipid systems driving immune inflammation and tissue damage in COVID-19 and GD, respectively. It is therefore expected that combined targeting of the complement and sphingolipid pathways could ameliorate the tissue destruction, organ failure, and death in patients at high-risk of developing severe cases of COVID-19.

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.

Overview of the retina and imaging in patients with severe acute respiratory syndrome coronavirus 2

INTRODUCTION

The role of the human eye in severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is still under investigation. The pathophysiology of the ocular findings is arduous when dealing with critically ill Covid-19 patients with comorbidities. Multiorgan involvement and the effects of inflammation, infection and systemic treatment on the retina are complex, and comparison of studies is difficult. Most studies in human patients have investigated the anterior segment, whereas few reports deal with the posterior segment of the eye. The present review aims to evaluate the retinal manifestations and imaging features in COVID-19 patients.

METHODS

Studies on the retinal manifestations and retinal imaging in COVID-19 patients published through June 2021 were reviewed. We included cross-sectional and case-control studies, case series, case reports and correspondence in the analysis.

RESULTS

Flame-shaped hemorrhages, cotton wool spots, augmented diameter and tortuosity of retinal vessels were found on funduscopic examination. Peripapillary, macular retinal nerve fiber layer and ganglion cell layer thickness alterations were reported on spectral domain optical coherence tomography. Reduced vessel density of the superficial and deep retinal capillary plexus on optical coherence tomography angiography was reported.

CONCLUSIONS

Retinal complications may arise in COVID-19 patients. Although no consensus on presentation is currently available, retinal funduscopy and imaging has shown neuronal and vascular alterations. Systemic neurological complications and microangiopathy are associated with SARS-COV-2; thus, as the retina has a neuronal and vascular component, funduscopy and retinal imaging on COVID-19 patients can provide further insight to SARS-COV-2 disease and the follow-up of patients.

Progression of Antiviral Agents Targeting Viral Polymerases

Viral DNA and RNA polymerases are two kinds of very important enzymes that synthesize the genetic materials of the virus itself, and they have become extremely favorable targets for the development of antiviral drugs because of their relatively conserved characteristics. There are many similarities in the structure and function of different viral polymerases, so inhibitors designed for a certain viral polymerase have acted as effective universal inhibitors on other types of viruses. The present review describes the development of classical antiviral drugs targeting polymerases, summarizes a variety of viral polymerase inhibitors from the perspective of chemically synthesized drugs and natural product drugs, describes novel approaches, and proposes promising development strategies for antiviral drugs.

Ocular effects caused by viral infections and corresponding vaccines: An overview of varicella zoster virus, measles virus, influenza viruses, hepatitis B virus, and SARS-CoV-2

Many viral infections can affect vision and the visual system. Vaccination to prevent diseases is commonplace today, acting by stimulating an immune response without developing the pathology. It involves the production of persisting antibodies against the pathogen and the activation of T cells. Certain diseases have already been eradicated by rigorous vaccination campaigns, while others are hoped to be eliminated soon. Vaccines currently available on the market are largely safe, even if they can rarely cause some adverse effects, such as ocular complications. Analyzing existing literature, we aimed to compare the pathological effects on the eye due to the most common viral infections [in particular varicella zoster virus (VZV), measles virus, influenza viruses, hepatitis B virus, and SARS-CoV-2] with the possible ocular adverse effects of their relative vaccines, in order to establish a risk-benefit relationship from an ophthalmological point of view.

Pathogenesis of Vascular Retinal Manifestations in COVID-19 Patients: A Review

Pandemic infection secondary to coronavirus disease 2019 (COVID-19) had an important impact on the general population affecting not only respiratory tract but also many other organs. Ocular manifestations are quite common at the level of the anterior segment (conjunctivitis, dry eye), while posterior segment and, in particular, retinal findings are less frequent. In the retina, COVID-19 is associated with vascular events. Since retinal arteries and veins represent an accessible window to the microvasculature of the rest of the body, a better understanding of the profile of retinal vascular occlusive events may help elucidate mechanisms of thrombo-occlusive complications in other organs in patients affected by COVID-19. In this review, we conducted a systematic literature search focused on retinal arterial and/or retinal venous manifestations. Twenty-one studies were included, describing a wide range of manifestations from mild signs like cotton wool spots, focal and flame-shaped hemorrhages, and vein dilation to more severe retinal artery and vein occlusions. Two principal pathogenetic mechanisms are considered responsible for these complications: a hypercoagulative state and a massive inflammatory response leading to a disseminated intravascular coagulation-like syndrome.

Discovery of putative inhibitors against main drivers of SARS-CoV-2 infection: Insight from quantum mechanical evaluation and molecular modeling

SARS-CoV-2 triggered a worldwide medical crisis, affecting the world’s social, emotional, physical, and economic equilibrium. However, treatment choices and targets for finding a solution to COVID-19’s threat are becoming limited. A viable approach to combating the threat of COVID-19 is by unraveling newer pharmacological and therapeutic targets pertinent in the viral survival and adaptive mechanisms within the host biological milieu which in turn provides the opportunity to discover promising inhibitors against COVID-19. Therefore, using high-throughput virtual screening, manually curated compounds library from some medicinal plants were screened against four main drivers of SARS-CoV-2 (spike glycoprotein, PLpro, 3CLpro, and RdRp). In addition, molecular docking, Prime MM/GBSA (molecular mechanics/generalized Born surface area) analysis, molecular dynamics (MD) simulation, and drug-likeness screening were performed to identify potential phytodrugs candidates for COVID-19 treatment. In support of these approaches, we used a series of computational modeling approaches to develop therapeutic agents against COVID-19. Out of the screened compounds against the selected SARS-CoV-2 therapeutic targets, only compounds with no violations of Lipinski’s rule of five and high binding affinity were considered as potential anti-COVID-19 drugs. However, lonchocarpol A, diplacol, and broussonol E (lead compounds) were recorded as the best compounds that satisfied this requirement, and they demonstrated their highest binding affinity against 3CLpro. Therefore, the 3CLpro target and the three lead compounds were selected for further analysis. Through protein–ligand mapping and interaction profiling, the three lead compounds formed essential interactions such as hydrogen bonds and hydrophobic interactions with amino acid residues at the binding pocket of 3CLpro. The key amino acid residues at the 3CLpro active site participating in the hydrophobic and polar inter/intra molecular interaction were TYR54, PRO52, CYS44, MET49, MET165, CYS145, HIS41, THR26, THR25, GLN189, and THR190. The compounds demonstrated stable protein–ligand complexes in the active site of the target (3CLpro) over a 100 ns simulation period with stable protein–ligand trajectories. Drug-likeness screening shows that the compounds are druggable molecules, and the toxicity descriptors established that the compounds demonstrated a good biosafety profile. Furthermore, the compounds were chemically reactive with promising molecular electron potential properties. Collectively, we propose that the discovered lead compounds may open the way for establishing phytodrugs to manage COVID-19 pandemics and new chemical libraries to prevent COVID-19 entry into the host based on the findings of this computational investigation.

Bilateral Post Fever Retinitis With Retinal Vascular Occlusions Following Severe Acute Respiratory Syndrome Corona Virus (SARS-CoV2) Infection

INTRODUCTION

As the world fights the pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several reports of retinal manifestations of the disease are emerging. Post fever retinitis is a well reported ocular inflammatory reaction to multiple invasive agents, be it virus, bacteria or other microbial agent.

PURPOSE

We report an interesting case of bilateral multifocal retinitis with multiple vascular occlusions in a patient, three weeks after a febrile illness.

RESULTS

Investigations to ascertain the cause of fever resulted in identifying ephemeral seropositivity for several different Ribonucleic acid (RNA) viruses. The retinitis was managed with systemic steroids, doxycycline and anticoagulants with improvement in vision.

CONCLUSION

High and persistent seropositive response against (SARS-CoV-2) helped us to narrow it as the causative agent but the cross reactivity of SARS-CoV-2 with other viruses can be misleading and needs careful interpretation.

SARS-CoV-2 among the Potential Viral Triggers for Vogt-Konayagi-Harada Disease: First Case Report and Literature Review

OBJECTIVE

To describe a case of Vogt-Koyanagi-Harada (VKH) disease associated with the novel coronavirus disease 2019 (COVID-19).

MATERIALS AND METHODS

A retrospective review of patient records was carried out to obtain data for a case report. A literature review was conducted of cases of uveitis associated with COVID-19 reported to date.

CASE DESCRIPTION

A 32-year-old Hispanic female presented with bilateral granulomatous panuveitis consisting of VKH disease 2 weeks after a clinical course of COVID-19. Both eyes presented with anterior uveitis and edematous hyperemic papilla with flame-shaped peripapillary hemorrhages, macula-off serous retinal detachments with subretinal fluid, and vitritis. A complete systemic work-up was performed to exclude infectious or inflammatory etiologies. Ocular inflammatory signs and systemic symptoms improved with corticosteroid and immunomodulatory therapy.

CONCLUSION

SARS-CoV-2 can be a potential immunological trigger for VKH disease. Patients presenting with panuveitis and a history of a previous flu-like illness should raise clinical suspicion of the presence of SARS-CoV-2 in the context of the ongoing global pandemic.

Evaluation of Retinal Microvascular Impairment after COVID-19 and its Clinical Correlates Using Optical Coherence Tomography Angiography

Objectives

Retinal vascular complications have been described in patients with coronavirus disease 2019 (COVID-19). This study aimed to analyze retinal microvascular changes and their correlations with clinical findings.

Materials and Methods

This case-controlled study was conducted in a university hospital. The right eyes of 52 otherwise healthy patients recovered from COVID-19 and 42 healthy controls were examined with optical coherence tomography angiography. Mann-Whitney U test was used to compare vessel density (VD) and foveal avascular zone (FAZ) parameters. Associations with treatment choices, pneumonia, and laboratory findings were analyzed.

Results

Twenty-nine patients (56%) and 18 healthy controls (43%) were men. Mean age of the COVID-19 group was 39.00±13.04 years. Twenty-two patients had pneumonia, 18 (35%) received hydroxychloroquine (HCQ), 17 (33%) received HCQ plus low-molecular-weight heparin (LMWH), and 10 (19%) received favipiravir. The patient group had lower parafoveal VD in the superficial capillary plexus (SCP) and lower parafoveal VD and perifoveal VD in the deep capillary plexus (DCP) than controls (p=0.003, p=0.004, p=0.001). FAZ area did not differ significantly (p=0.953). Perifoveal VD in the DCP was also significantly lower in the HCQ+LMWH group than the HCQ group (p=0.020) and in the presence of pneumonia (p=0.040). C-reactive protein (CRP) and ferritin levels were negatively correlated with perifoveal VD in the DCP (r=-0.445, p=0.023; r=-0.451, p=0.040). Ferritin was also negatively correlated with parafoveal VD in the SCP (r=-0.532, p=0.013).

Conclusion

Parafoveal and perifoveal VD was found to be lower in the COVID-19 group. Presence of pneumonia, need for LMWH prophylaxis, and levels of CRP and ferritin were found to be negatively associated with retinal VD. Large-scale studies are needed to evaluate the clinical importance.

White Dot Syndrome Report in a SARS-CoV-2 Patient

Our purpose was to report clinical features in bilateral white dot syndrome in a 47-year-old female patient who was tested positive for the SARS-CoV-2. A 47-year-old female visited our department with complaints of bilateral photophobia and blurred vision in both her eyes. She visited our department during the pandemic period after her PCR-proven SARS-CoV-2 positivity. Her symptoms were chills and fever with a temperature of 40.0°C, associated with fatigue, sweat, and complete loss of taste. Besides basic ophthalmological examinations, ocular diagnostic testing were made to differentiate between specific white dot syndromes with suggestive features of fluorescein angiography, optical coherence tomography, and fundus autofluorescence. Laboratory tests were ordered, including immunserological and haematological ones. Eye examination revealed mild bilateral vitritis and white dots in the fundus of both eyes, including the macula explaining the blurred vision. Herpes simplex virus reactivation was proved, after the SARS-CoV-2 infection. Local corticosteroids were given according to the European Reference Network's recommendations for patients with uveitis during the COVID-19 pandemic. Our report demonstrates that white dot syndrome with blurred vision could be associated with SARS-CoV-2 infection, being potentially sight-threatening because of macular involvement. Ophthalmological examinations found posterior uveitis white dot syndrome, and this should call attention to the risk of acute 2019-CoV infection or occurred 2019-CoV infection. Immunodeficiency favours the occurrence of other viral infections, such as herpes virus infections. Everybody should be aware of the risk of 2019-CoV infection, especially professionals, social workers, and those who work or live with elder people and people with immunodeficiency.

A case of severe endogenous endophthalmitis with orbital cellulitis post COVID-19

Coronavirus disease 2019 (COVID-19) is a novel pandemic viral illness which may lead to severe respiratory diseases. However, its ophthalmic manifestations are still not well understood. There could be serious complications involving various organs in patients with the disease and in those who are recovering, or have recovered, from COVID-19. Endogenous endophthalmitis, was a rare occurrence in the past but has increased in the post-COVID-19 pandemic. Endogenous endophthalmitis results from hematogenous spread from a remote primary source. A 55-year-old man with confirmed COVID-19 presented to a local hospital with unilateral gradual loss of vision and swelling of the left eye that occurred 10 days after discharge from the hospital. Based on detailed ophthalmic examination, this patient with a co-morbidity, namely diabetes mellitus was placed in the intensive care unit where he was given corticosteroids and ventilation for two weeks. Most patients requiring mechanical ventilation may experience disorders of the eye, and it may be difficult to treat these occurrences while the patient remains in ICU. COVID-19 can lead to ocular complications especially in the late stages of infection. Follow-up of post COVID-19 patients is crucial to monitor possible ocular complaints including endophthalmitis as early diagnosis and treatment is essential to salvage vision.

Update on overview of ocular manifestations of COVID-19

The coronavirus disease 2019 (COVID-19) has become the most critical health crisis at present, and research is continued about the exact pathophysiology, presentations, and complications of this pandemic. It influences several organs, and many studies have addressed the organs, the involvement of which during the COVID-19 results in patients' death. One of the important organs that can be involved during COVID-19, which is also a transmission route of the disease, is the eye. According to the evidence, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can have ocular manifestations and complications. According to the literature, conjunctivitis is the most common presentation, which can develop at any stage of COVID-19 (during and even after the disease), and the major pathophysiology of the eye involvement during the disease is attributed to the direct effect of the virus on the eyes, tissue damage caused by inflammation, underlying diseases, and the adverse effect of the medications prescribed. There are also reports of life-threatening complications, such as rhino-orbital cerebral mucormycosis, which require urgent treatment and are associated with a great mortality rate. Ocular manifestations may also be the presentation of a life-threatening event, such as stroke; therefore, it is necessary to pay great attention to the ocular manifestations during COVID-19. In this review, after about 2 years of the pandemic started, we present a narrative review on ocular manifestations during COVID-19, categorized into three main categories; ophthalmic, orbital, and neuro-ophthalmological manifestations with a detailed description of the presenting symptoms, risk factor, diagnostic, and therapeutic strategies suggested for each.

Purtscher-like retinopathy in a patient with COVID-19-associated coagulopathy

The most frequently reported ophthalmic manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is conjunctivitis. We have described a case of Purtscher-like retinopathy in a patient with severe coronavirus disease 2019 (COVID-19)-associated coagulopathy. A young woman with multiple comorbidities was admitted for COVID-19-related acute respiratory distress syndrome. Her course was complicated by fungemia. Ophthalmic examination revealed bilateral posterior pole, intraretinal lesions and fluconazole was added for presumed fungal retinitis. At 1-week follow-up, widespread peripapillary cotton-wool spots and hemorrhages suggestive of Purtscher-like retinopathy were observed. The levels of D-dimers, fibrinogen, and C-reactive protein were markedly elevated prior to our consultation, indicating preceding prothrombotic and pro-inflammatory states. Subsequent venous duplex revealed deep venous thrombosis in the right subclavian and internal jugular veins. Von Willebrand factor indices were markedly elevated, suggesting severe COVID-19-associated coagulopathy. Purtscher-like retinopathy, a rare occlusive microangiopathy has been described in various pro-inflammatory and prothrombotic conditions. To the best of our knowledge, this is the first report of Purtscher-like retinopathy in COVID-19-associated coagulopathy.

Structural alterations of the choroid evaluated using enhanced depth imaging optical coherence tomography in patients with coronavirus disease

PURPOSE

To assess choroidal changes using enhanced depth imaging optical coherence tomography in coronavirus disease (COVID-19).

METHODS

Thirty-two patients with moderate COVID-19 and 34 healthy subjects were included in the study. Choroidal thickness was measured at 3 points as follows: at the subfovea, 1500 mm nasal to the fovea, and 1500 mm temporal to the fovea. The total choroidal area, luminal area, stromal area, and choroidal vascular index were measured with Image-J. All the measurements were performed during the disease and at 4 months after remission.

RESULTS

In the patient group, the subfoveal, nasal, and temporal choroidal thicknesses were decreased as compared with those in the controls, but without statistically significant differences (p=0.534, p=0.437, and p=0.077, respectively). The mean total choroidal, stromal, and luminal areas and choroidal vascular index were statistically significantly decreased in the patient group (p<0.001, p=0.001, p=0.001, and p=0.003; respectively). At 4 months after remission, the choroidal structural parameters and choroidal vascular index revealed statistically significant increases as compared with the baseline measurements in the patients with COVID-19 (all p<0.001 and p=0.047, respectively).

CONCLUSION

The choroidal vascular and stromal parameters showed significant transient decreases during the disease course of COVID-19.

Human Responses in Public Health Emergencies for Infectious Disease Control: An Overview of Controlled Topologies for Biomedical Applications

COVID-19 originated in Wuhan city of Hubei Province in China in December three years ago. Since then, it has spread to more than 210 countries and territories. This disease is caused by Severe Acute Respiratory Syndrome Coronavirus 2. The virus has a size of one to two nanometers and a single-stranded positive RNA. Droplets spread the virus from coughing and sneezing. This condition causes coughing, fever, acute respiratory problems, and even death. According to the WHO, the virus can survive outside the body for several hours. This research aimed to determine how environmental factors influenced the COVID-19 virus's survival and behavior, as well as its transmission, in a complex environment. Based on the results, virus transmissions are influenced by various human and environmental factors such as population distribution, travel, social behavior, and climate change. Environmental factors have not been adequately examined concerning the transmission of this epidemic. Thus, it is necessary to examine various aspects of prevention and control of this disease, including its effects on climate and other environmental factors.

Bilateral Acute Depigmentation of the Iris (BADI) following Covid-19 Infection

PURPOSE

To present a case of bilateral acute iris depigmentation after covid 19 infection.

CASE REPORT

A 55-year-old female presented with binocular pain and blurred vision a month after being diagnosed with severe acute respiratory syndrome - coronavirus-2 (SARS-CoV-2). She presented pigment dispersion in the anterior chamber and pigment depositions on the corneal endothelium. The patient was treated with dexamethasone and during follow-up visits, the pigment dispersion decreased and the symptoms ceased.

CONCLUSIONS

Covid-19 infection may be associated with rare ocular disorders such as BADI.

Possible Association between Vogt-Koyanagi-Harada Disease and Coronavirus Disease Vaccine: A Report of Four Cases

Vogt-Koyanagi-Harada (VKH) syndrome is an autoimmune, multisystemic disease characterized by severe bilateral granulomatous posterior, which can occur due to viral infection or vaccination. We report four cases that had a likely association between VKH disease and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Two patients had VKH symptoms within 1 and 2 weeks after receiving the ChAdOx1 nCoV-19 vaccine. One patient presented with VKH symptoms 5 days after receiving the BNT162b2 vaccine, and one patient had symptoms within 4 weeks after receiving the CoronaVac vaccine. Early diagnosis and treatment of VKH disease are essential for the visual prognosis of this aggressive disease. Further in-depth studies are necessary to investigate this likely association to enable ophthalmologists to identify new assumed correlations between the diseases described in this study.

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.

Consecutive central and branch retinal vein occlusions in the same eye of a young healthy COVID-19 patient: A unique case report

Purpose

To report a case of consecutive central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) in the same eye correlated with coronavirus disease (COVID-19) of the otherwise healthy patient.

Observations

A 39-year-old woman with the diagnosis of COVID-19 infection for two weeks presented with a nonischemic central retinal vein occlusion (CRVO) in her right eye. The patient was on low-dose aspirin for anticoagulant prophylaxis (100 mg/day) for a week when the CRVO occurred. She had no history of any systemic risk factors for retinal vein occlusion (RVO) and her systemic evaluation failed to identify an etiology for her unilateral CRVO. While she was on monthly follow-up with no additional treatment, she experienced sudden visual acuity decrease in the same eye four months after the first RVO incident and one month after the cessation of aspirin intake. Her best corrected visual acuity (BCVA) was decreased from 20/25+ to 20/63. Her fundoscopic examination revealed increased intraretinal hemorrhages, dilated tortuous veins in the upper hemifield and macular edema. The central macular thickness measurement by optic coherence tomography was increased from 234 μm to 700 μm. The patient refused to undergo a fundus fluorescein angiography. After the diagnosis of the branch retinal vein occlusion with cystoid macular edema was done, the aspirin prophylaxis was restarted, and she received three intravitreal antivascular endothelial growth factor one month apart for her macular edema. Her BCVA improved to 20/20, and macular edema disappeared without any recurrence during the 6-month follow-up.

Conclusions and importance

To the best of our knowledge, this unique case is the first report of consecutive RVOs in the same eye of a healthy young patient associated with COVID-19. As our case report demonstrated, close follow-up and timely initiation of appropriate treatment could give rise to complete resolution of RVO.

Orbital apex inflammation: a curious case of COVID-19

A 25-year-old man presented to an urgent care facility with sudden loss of vision in his right eye, diplopia, and anosmia. He tested positive by reverse-transcription polymerase chain reaction for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Nine days later, he presented at our emergency department, at which time ophthalmic examination revealed reduced visual acuity in the right eye, with poor color vision and a relative afferent pupillary defect. He had a moderate adduction deficit and mild hypertropia of the right eye, with an intermittent exotropia. Magnetic resonance imaging of the orbits revealed asymmetric, abnormal enhancement of the right optic nerve sheath extending to the right orbital apex. His ocular symptoms resolved completely with systemic steroids. All infectious and inflammatory labs returned negative except for COVID-19. Ocular findings have been consistently implicated throughout this pandemic. This case highlights an unidentified presentation with optic nerve involvement and orbital inflammation.

Ocular manifestations of COVID-19 in the pediatric age group

The coronavirus disease 2019 (COVID-19) is now known to be associated with several ocular manifestations. The literature thoroughly discussed those that affect adults, with a lesser focus in the pediatric age group. We aim to outline the various pediatric ocular manifestations described in the literature. The manifestations may be divided into isolated events attributed to COVID-19 or occurring in the new multisystem inflammatory syndrome in children (MIS-C), a novel entity associated by COVID-19 infection. Ocular manifestations have virtually affected all ages. They manifested in neonates, infants, children, and adolescents. Episcleritis, conjunctivitis, optic neuritis, cranial nerve palsies, retinal vein occlusion, retinal vasculitis, retinal changes, orbital myositis, orbital cellulitis were reported in the literature with this emerging viral illness. Conjunctivitis was the most common ocular manifestation in MIS-C in nearly half of the patients. Other ocular manifestations in MIS-C were anterior uveitis, corneal epitheliopathy, optic neuritis, idiopathic intracranial hypertension, and retinitis. The clinical outcome was favorable, and children regain their visual ability with minimal or no deficits in most of the cases. Further follow-up may be warranted to better understand the long-term effects and visual prognosis.

Optical biometric measurements in patients with previous COVID-19 treatment

Background

We aimed to compare optical biometric measurements using optical biometry in patients with previously received COVID-19 treatment and a control group.

Methods

In this cross-sectional study, patients with previously received COVID-19 treatment formed the COVID-19 group and age- and sex-matched healthy participants formed the control group. Optical biometric measurements including keratometry, corneal astigmatism, astigmatic axis, central corneal thickness, anterior chamber depth, and axial length were made using a Nidek optical biometer (AL-Scan; Nidek Co., Ltd., Japan).

Results

Measurements of keratometry (p = 0.79), corneal astigmatism (p = 0.41), axial length (p = 0.96), anterior chamber depth (p = 0.59), and central corneal thickness (p = 0.37) were similar between the COVID-19 and control groups. The astigmatic axis type taken from 2.4 mm of the cornea showed significant difference between the two groups (p = 0.02, χ2), while the measurements taken from 3.3 mm of the cornea were similar (p = 0.10, χ2). In the subgroup analysis, axial length, anterior chamber depth, and central corneal thickness measurements were found to be statistically significantly higher in male patients of the COVID-19 group (p = 0.02; p = 0.001; p = 0.02, t test).

Conclusion

The changes in optical biometric measurements found in our study were due to the fact that COVID-19 is more frequent and severe in males, SARS-CoV‑2 can attach to the cornea via ACE‑2 receptors, and favipiravir can reach the aqueous humor. To our knowledge, there is no study on this subject to date, and therefore more research is needed to shed light on this topic.

Mucosal vaccine delivery: A focus on the breakthrough of specific barriers

Mucosal vaccines can effectively induce an immune response at the mucosal site and form the first line of defense against microbial invasion. The induced mucosal immunity includes the proliferation of effector T cells and the production of IgG and IgA antibodies, thereby effectively blocking microbial infection and transmission. However, after a long period of development, the transformation of mucosal vaccines into clinical use is still relatively slow. To date, fewer than ten mucosal vaccines have been approved. Only seven mucosal vaccines against coronavirus disease 2019 (COVID-19) are under investigation in clinical trials. A representative vaccine is the adenovirus type-5 vectored COVID-19 vaccine (Ad5-nCoV) developed by Chen and coworkers, which is currently in phase III clinical trials. The reason for the limited progress of mucosal vaccines may be the complicated mucosal barriers. Therefore, this review summarizes the characteristics of mucosal barriers and highlights strategies to overcome these barriers for effective mucosal vaccine delivery.

Neurological and Head/Eyes/Ears/Nose/Throat Manifestations of COVID-19: A Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVE

Coronavirus disease 2019 (COVID-19) has been associated with various neurological and atypical head/eyes/ears/nose/throat (HEENT) manifestations. We sought to review the evidence for these manifestations.

METHODS

In this systematic review and meta-analysis, we compiled studies published until March 31, 2021 that examined non-respiratory HEENT, central, and peripheral nervous system presentations in COVID-19 patients. We included 477 studies for qualitative synthesis and 59 studies for meta-analyses.

RESULTS

Anosmia, ageusia, and conjunctivitis may precede typical upper/lower respiratory symptoms. Central nervous system (CNS) manifestations include stroke and encephalopathy, potentially with brainstem or cranial nerve involvement. MRI studies support CNS para-/postinfectious etiologies, but direct neuroinvasion seems very rare, with few cases detecting Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the CNS. Peripheral nervous system (PNS) manifestations include muscle damage, Guillain-Barre syndrome (GBS), and its variants. There was moderate-to-high study heterogeneity and risk of bias. In random-effects meta-analyses, anosmia/ageusia was estimated to occur in 56% of COVID-19 patients (95% CI: 0.41-0.71, I2:99.9%), more commonly than in patients without COVID-19 (OR: 14.28, 95% CI: 8.39-24.29, I2: 49.0%). Neurological symptoms were estimated to occur in 36% of hospitalized patients (95% CI: 0.31-0.42, I2: 99.8%); ischemic stroke in 3% (95% CI: 0.03-0.04, I2: 99.2%), and GBS in 0.04% (0.033%-0.047%), more commonly than in patients without COVID-19 (OR[stroke]: 2.53, 95% CI: 1.16-5.50, I2: 76.4%; OR[GBS]: 3.43,1.15-10.25, I2: 89.1%).

CONCLUSIONS

Current evidence is mostly from retrospective cohorts or series, largely in hospitalized or critically ill patients, not representative of typical community-dwelling patients. There remains a paucity of systematically gathered prospective data on neurological manifestations. Nevertheless, these findings support a high index of suspicion to identify HEENT/neurological presentations in patients with known COVID-19, and to test for COVID-19 in patients with such presentations at risk of infection.

Diplopia and Optic Disc Edema as the Ocular Manifestations of COVID-19 in a Seven-Year-Old Child

Serious ocular complications due to SARS-CoV-2 disease in children are rare. Herein, we present a case report of a seven-year-old patient, who was diagnosed with pediatric inflammatory multisystem syndrome (PIMS) due to COVID-19 and developed the ocular manifestations comprising diplopia and binocular optic disc edema. The patient condition improved within few weeks without any ocular sequels so far.

Spectral-domain optical coherence tomography assessment of retinal and choroidal changes in patients with coronavirus disease 2019: a case-control study

Objectives

This study aimed to evaluate the retinal and choroidal changes in the macular region of patients with Coronavirus Disease 2019 (COVID-19) using structural spectral-domain optical coherence tomography (SD-OCT) analysis.

Methods

This cross-sectional observational case-control study included patients recovered from COVID-19. The COVID-19 in all participants was confirmed using the reverse transcription-polymerase chain reaction (RT-PCR) technique. The participants had mild to moderate degree of disease without a history of hospitalization, steroid usage, or blood saturation below 92%. Macular SD-OCT was performed at least two weeks and up to one month after recovery from systemic COVID-19. Quantitative and qualitative changes detected by macular SD-OCT imaging were evaluated in COVID-19 recovered patients and compared with the results of age-matched normal controls.

Results

Participants in this study included 30 cases (60 eyes) and 60 healthy controls (120 eyes). In total, 17 (28.3%) eyes in patient group showed at least one abnormal finding indicated by macular SD-OCT imaging included hyperreflective lesions in different retinal layers. In addition, dilated choroidal vessels and retinal pigment epitheliopathy were evident in 41 (68.3.6%) and 4 (6.6%) eyes in patient group, respectively, and their OCT findings resembled those with pachychoroid spectrum. No statistically significant differences were observed in retinal layers or retinal volume between the two groups. The mean ± SD subfoveal choroidal thickness (SFCT) was determined at 380.3 ± 12.40 μm, which was significantly thicker than that in control group (310.7 ± 57.5 μm) (P < 0.001).

Conclusion

Regarding retinal thickness, no significant change was observed in different retina layers of patients with COVID-19; however, there were striking qualitative changes, such as hyperreflective lesions in different retinal layers. The evaluation of choroidal structure and thickness demonstrated remarkable abnormal pachyvessels and significant thickening of the SFCT but the clinical significance of these findings is unknown.

SARS-CoV-2: phenotype, genotype, and characterization of different variants

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19), a major international public health concern. Because of very similar amino acid sequences of the seven domain names, SARS-CoV-2 belongs to the Coronavirinae subfamily of the family Coronaviridae, order Nidovirales, and realm Riboviria, placed in exceptional clusters, but categorized as a SARS-like species. As the RNA virus family with the longest genome, the Coronaviridae genome consists of a single strand of positive RNA (25-32 kb in length). Four major structural proteins of this genome include the spike (S), membrane (M), envelope (E), and the nucleocapsid (N) protein, all of which are encoded within the 3' end of the genome. By engaging with its receptor, angiotensin-converting enzyme 2 (ACE2), SARS-CoV-2 infects host cells. According to the most recent epidemiological data, as the illness spread globally, several genetic variations of SARS-CoV-2 appeared quickly, with the World Health Organization (WHO) naming 11 of them. Among these, seven SARS-CoV-2 subtypes have received the most attention. Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.617.2) are now designated as variations of concern (VOC) (B.1.1.529). Lambda (C.37) and Mu are variations of interest (VOI) (B.1.621). The remaining six are either being monitored or are no longer considered a threat. On the basis of studies done so far, antiviral drugs, antibiotics, glucocorticoids, recombinant intravenous immunoglobulin, plasma therapy, and IFN-α2b have been used to treat patients. Moreover, full vaccination is associated with lower infection and helps prevent transmission, but the risk of infection cannot be eliminated completely in vaccinated people.

Hastanede yatan yeni Coronavirus 2019 hastalarının gözyaşı örneklerinde Severe Acute Respiratory Syndrome Coronavirus-2 RNA’larının değerlendirilmesi

Aim: We aimed to detect the presence of Severe Acute Respiratory Syndrome Coronavirus-2 RNA in the tears of patients with confirmed novel Coronavirus disease 2019. Materials and Methods: This prospective study was performed at Health Science University Kartal Dr. Lutfi Kırdar City Hospital between 13-21 May 2020. Nasopharyngeal and tear samples of 15 patients with novel Coronavirus disease 2019 was performed for real-time polymerase chain reaction assay. Ocular and systemic signs and symptoms, chest computed tomographic scans, and results of laboratory blood tests as well as the drugs used for the treatment were noted and analyzed. Results: Of the 15 patients nine (60%) were male and six (40%) were female. Mean age of the patients was 53.86±20.20 (21-89) years. Among them nine patients (60%) were positive for novel coronavirus disease 2019 on real-time polymerase chain reaction from nasopharyngeal specimens. None of the patients was positive for real-time polymerase chain reaction for Severe Acute Respiratory Syndrome Coronavirus-2 in tear specimens. Only two of 15 patients had bilateral conjunctivitis. These two patients had positive results for Severe Acute Respiratory Syndrome Coronavirus-2 on real-time polymerase chain reaction from nasopharyngeal swabs. Conclusion: In this study Severe Acute Respiratory Syndrome Coronavirus-2 RNA could not be detected in the tear samples of the patients with confirmed novel Coronavirus disease 2019 with or without ocular symptoms and signs.

Biological Properties of SARS-CoV-2 Variants: Epidemiological Impact and Clinical Consequences

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a virus that belongs to the coronavirus family and is the cause of coronavirus disease 2019 (COVID-19). As of May 2022, it had caused more than 500 million infections and more than 6 million deaths worldwide. Several vaccines have been produced and tested over the last two years. The SARS-CoV-2 virus, on the other hand, has mutated over time, resulting in genetic variation in the population of circulating variants during the COVID-19 pandemic. It has also shown immune-evading characteristics, suggesting that vaccinations against these variants could be potentially ineffective. The purpose of this review article is to investigate the key variants of concern (VOCs) and mutations of the virus driving the current pandemic, as well as to explore the transmission rates of SARS-CoV-2 VOCs in relation to epidemiological factors and to compare the virus's transmission rate to that of prior coronaviruses. We examined and provided key information on SARS-CoV-2 VOCs in this study, including their transmissibility, infectivity rate, disease severity, affinity for angiotensin-converting enzyme 2 (ACE2) receptors, viral load, reproduction number, vaccination effectiveness, and vaccine breakthrough.

The Impact of the First COVID-19 Lockdown Period on the Inpatient and Outpatient Volume of a University Based Tertiary Referral Center with Corneal Subspecialization in Germany

Background/Aims

To determine the impact of COVID-19 on the number of in- and outpatients surgical and diagnostic procedures performed at a southwestern German university hospital with corneal subspecialization.

Methods

A retrospective examination of the number of inpatients, several outpatients subunits, in- and outpatient surgeries as well as diagnostic procedures at the Department of Ophthalmology, Saarland University Medical Centre during the COVID-19 pandemic "lockdown period" from 18 March until 8 May 2020 in comparison with the corresponding period in 2019 (source: SAP database and electronic patient record FIDUS).

Results

The year 2020 showed a significant decrease in the number of inpatient surgeries with a total number of 285 vs 412 in 2019. However, the number of corneal transplantations increased significantly (60 in 2020 vs 54 in 2019, p=0.0089). In the various outpatient units of our department, we observed a significant decrease in the number of consultations (1.711 in 2020 vs 3.194 in 2019), especially for cataract surgery consultations (34 vs 137, p<0.0001). The number of outpatient surgeries was significantly reduced in 2020, especially for cataract surgery (64 vs 216, p=0.007) and intravitreal injections (577 vs 768, p<0.0001).

Conclusion

Despite taking all the necessary precautions to ensure that our medical care can continue to be available reliably and completely safe during the "Corona lockdown period", the number of in- and outpatient surgeries and the number of outpatient consultations decreased significantly. However, the number of corneal transplantations still increased.