The Ocular Surface and the Coronavirus Disease 2019: Does a Dual 'Ocular Route' Exist?

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.

Successful Management of Bilateral Uncontrolled Advanced Primary Open Angle Glaucoma in a Pregnant Woman during the Restrictive COVID-19 Lockdown

COVID-19 is a viral illness that can cause severe respiratory symptoms. COVID-19 has caused a worldwide pandemic that necessitated many countries to perform a national lockdown. In Jordan, a lockdown was imposed by the government. During the lockdown, the hospitals were only dealing with outpatient emergency cases, urgent referrals from primary or secondary health institutions, and inpatients whose medical conditions required keeping them admitted. Elective clinics and surgeries were canceled. At the King Abdullah University Hospital (KAUH), which is the only tertiary center in northern Jordan, we dealt with an unusual case of uncontrolled and advanced primary open angle glaucoma in a 38-year-old pregnant female patient. The patient was presented with an intraocular pressure (IOP) of 53 mmHg in the right eye and 40 mmHg in the left eye despite using dorzolamide and timolol eye drops twice daily. The angle was opened in gonioscopy. The decision was made to implant Ahmed glaucoma valves (AGV) in each eye in one session under general anesthesia which was performed successfully. At the last follow-up visit 4 years later, the IOP was maintained at 15 mmHg.

Dacryoadenitis post COVID-19 infection and immunization

Dacryoadenitis can be a rare presentation following COVID-19 infection or can be an immunological response post COVID-19 vaccination. Herein we report two cases of lacrimal gland involvement, one post COVID-19 infection, and the other post COVID-19 vaccination. A definitive causal relationship, however, remains uncertain.

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

Quantitative assessment of the effect of SARS-CoV-2 on the corneal sub-basal nerve plexus of post-COVID-19 patients using in vivo confocal microscopy

OBJECTIVES

To investigate whether SARS-CoV-2 causes morphological changes in the corneal sub-basal nerve plexus (CSNP) of post-COVID-19 patients using in vivo confocal microscopy (IVCM).

METHODS

A total of 70 participants were included in the study and were divided into three groups. Post-COVID-19 patients with neurological manifestations were considered Group 1 (n = 24), and post-COVID-19 patients without neurological manifestations were considered Group 2 (n = 24). Healthy control participants were considered Group 3 (n = 22). The parameters of the CSNP, including nerve fibre density (NFD), nerve branch density (NBD), and nerve fibre length (NFL), were investigated in all participants using IVCM. Additionally, corneal sensitivity was tested by corneal esthesiometry.

RESULTS

The mean NFD, NBD, and NFL values of Group 1 (16.12 ± 4.84 fibre/mm², 27.97 ± 9.62 branch/mm², and 11.60 ± 2.89 mm/mm²) were significantly lower than those of Group 2 (19.55 ± 3.01 fibre/mm², 40.44 ± 7.16 branch/mm², and 15.92 ± 2.08 mm/mm²) and Group 3 (25.24 ± 3.75 fibre/mm², 44.61 ± 11.80 branch/mm², and 17.76 ± 3.32 mm/mm²) (p < 0.05 for all). Except the mean NFD value (p < 0.001), there were no significant differences in terms of the mean NBD and NFL values between Group 2 and Group 3 (p = 0.445, p = 0.085). The value of the mean corneal sensitivity was significantly higher in Group 3 (59.09 ± 1.97 mm) compared to Group 1 (55.21 ± 1.02 mm) and Group 2 (55.28 ± 1.18 mm) (p < 0.001, p < 0.001) but there was no significant difference between Group 1 and Group 2 (p = 1.000).

CONCLUSION

In post-COVID-19 patients, the mean parameters of CSNP were lower than in the control group. These differences were more pronounced in patients who had neurological manifestations of COVID-19.

Insights into organoid-based modeling of COVID-19 pathology

Since December 2019, various types of strategies have been applied due to the emergent need to investigate the biology and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to discover a functional treatment. Different disease modeling systems, such as mini-organ technology, have been used to improve our understanding of SARS-CoV-2 physiology and pathology. During the past 2 years, regenerative medicine research has shown the supportive role of organoid modeling in controlling coronavirus disease 2019 (COVID-19) through optimal drug and therapeutic approach improvement. Here, we overview some efforts that have been made to study SARS-CoV-2 by mimicking COVID-19 using stem cells. In addition, we summarize a perspective of drug development in COVID-19 treatment via organoid-based studies.

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 symptoms in COVID-19 infection: a survey study

BACKGROUND

Coronavirus disease 2019 (COVID-19) systemic symptoms and sequelae have been studied extensively, but less is known about the characterization, duration, and long-term sequelae of ocular symptoms associated with COVID-19 infection. The purpose of this study was to analyze the frequency, spectrum, and duration of ocular symptoms in participants with COVID-19 infection treated in inpatient and outpatient settings.

METHODS

A retrospective electronic survey was distributed to NIH employees and the public who reported testing positive for SARS-CoV-2. The anonymous survey collected information on demographics, past ocular history, systemic COVID-19 symptoms, and ocular symptoms.

RESULTS

A total of 229 (21.9% male and 78.1% female, mean age 42.5 ± 13.9) survey responses were included. Ocular symptoms were reported by 165 participants with a mean of 2.31 ± 2.42 symptoms. The most commonly reported ocular symptoms were light sensitivity (31.0%), itchy eyes (24.9%), tearing (24.9%), eye redness (24.5%), and eye pain (24.5%). Participants with ocular symptoms had a higher number of systemic symptoms compared to participants without ocular symptoms (mean 9.17 ± 4.19 vs 6.22 ± 3.63; OR: 1.21; 95% CI: 1.11 - 1.32; p < 0.001). Ocular symptoms were more common in those who reported a past ocular history compared to those who did not (81.8% vs 67.1%; OR: 2.17; 95% CI: 1.08 - 4.37; p = 0.03). Additionally, the onset of ocular symptoms occurred most frequently at the same time as systemic symptoms (47.5%), and 21.8% reported symptoms lasting ≥ 14 days.

CONCLUSIONS

Ocular surface-related symptoms are the most frequent ocular manifestations, and systemic disease severity is associated with the presence of ocular symptoms. Additionally, our results show that ocular symptoms can persist post-COVID-19 infection. Further work is needed to better understand ocular symptoms in COVID-19 and long-term sequelae.

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.

Outbreak of COVID-19-Related Myopia Progression in Adults: A Preliminary Study

PURPOSE

The COVID-19 pandemic has necessitated specific public health measures, resulting in the alteration of lifestyles, such as increased digital screen time and fewer outdoor activities. Such conditions have increased the progression of myopia in children. However, no investigation of myopia progression in early adulthood has been conducted during this period. Consequently, this study aimed to evaluate the outbreak of COVID-19-related myopia progression among adults at an optometry clinic during the COVID-19 pandemic.

MATERIALS AND METHODS

This was a retrospective cohort study in which participants aged 18-25 years who first visited (baseline) the optometry clinic between June 2019 and March 2020 were recruited for follow-up from November 2021 to March 2022. Spherical equivalent refraction (SER), uncorrected distance visual acuity (UCDVA), and binocular cross cylinder (BCC) were recorded at baseline and a follow-up visit. Using questionnaires, a survey was conducted to assess the lifestyle changes that transpired during the COVID-19 pandemic.

RESULTS

In total, 37 participants with a mean age of 22.5±1.4 years were enrolled, of which 89.2% were female. Following the outbreak of the COVID-19 pandemic, most participants self-reported increased daily use of digital devices (89.2%), online education (86.5%), and spending more time at home (94.6%), which increased by approximately 7.6±3.2 hours, 5.9±1.7 hours, and 13.2±7.5 hours, respectively. There were statistically significant differences between SER and BCC at baseline and after approximately 2 years of the COVID-19 pandemic (p < 0.05). The mean two-year myopia progression was -0.59±0.67 D (Maximum = 0.00 D, Minimum = -3.38 D).

CONCLUSION

This study revealed that myopia could progress during adulthood among those who have lived under public health measures intended to address the COVID-19 pandemic.

[Ocular manifestations in patients with COVID-19]

BACKGROUND

There are only few reports on ocular symptoms and manifestations in association with coronavirus disease 2019 (COVID-19).

OBJECTIVE

The aim of this study is to describe ocular manifestations in the anterior and posterior segments of the eye and to analyze viral prevalence in tears of patients with COVID-19.

METHODS

Hospitalized COVID-19 patients treated from 16 April 2020 to 7 January 2021 at this hospital were screened for ocular manifestations in the anterior and posterior segments. Conjunctival swabs were analyzed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA.

RESULTS

A total of 37 patients were enrolled in this study. In the anterior segment we found chemosis of the conjunctiva (5), hyposphagma (2) and conjunctivitis (1). In 11 patients vascular alterations and potentially disease-specific manifestations of the fundus were found in one or both eyes: retinal hemorrhages (5), cotton wool spots (5) and tortuosity (5). One patient demonstrated branch artery occlusion, one had branch retinal vein occlusion and two patients had positive conjunctival swab results in one or both eyes.

CONCLUSION

Our findings of the anterior segment are commonly known, although not specific for COVID-19. Various vascular fundus abnormalities were found in the study; however, it is unclear whether these were correlated to systemic comorbidities or whether they were caused or exacerbated by COVID-19. This study suggests that the risk of viral transmission via tears is low.

Evaluation of Face Shields, Goggles, and Safety Glasses as a Virus Transmission Control Measure to Protect the Wearer Against Cough Droplets

Face shields (also referred to as visors), goggles and safety glasses have been worn during the COVID-19 pandemic as one measure to control transmission of the virus. However, their effectiveness in controlling facial exposure to cough droplets is not well established and standard tests for evaluating eye protection for this application are limited. A method was developed to evaluate face shields, goggles, and safety glasses as a control measure to protect the wearer against cough droplets. The method uses a semi-quantitative assessment of facial droplet deposition. A cough simulator was developed to generate droplets comparable to those from a human cough. The droplets consisted of a UV fluorescent marker (fluorescein) in water. Fourteen face shields, four pairs of goggles and one pair of safety glasses were evaluated by mounting them on two different sizes of breathing manikin head and challenging them with the simulated cough. The manikin head was positioned in seven orientations relative to the cough simulator to represent various potential occupational exposure scenarios, for example, a nurse standing over a patient. Droplet deposition in the eyes, nose and mouth regions were visualised following three 'coughs'. Face shields, goggles, and safety glasses reduced, but did not eliminate exposure to the wearer from droplets such as those produced by a human cough. The level of protection differed based on the design of the personal protective equipment and the relative orientation of the wearer to the cough. For example, face shields, and goggles offered the greatest protection when a cough challenge was face on or from above and the least protection when a cough challenge was from below. Face shields were also evaluated as source control to protect others from the wearer. Results suggested that if a coughing person wears a face shield, it can provide some protection from cough droplets to those standing directly in front of the wearer.

Increased proinflammatory cytokines in tears correspond with conjunctival SARS-CoV-2 positivity in symptomatic COVID-19 patients

Tear fluid cytokine levels may serve as biomarkers of innate immune system response against SARS-CoV-2 infection. Therefore, our aim was to analyze panel of selected inflammatory cytokines in tears of COVID-19 patients in relation to presence of SARS-CoV-2 viral load in conjunctival secretions. In this study 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 in tear film collected from 232 symptomatic COVID-19 patients. SARS-CoV-2 ocular infection was confirmed based on positive conjunctival swab-based RT-PCR testing. Viral RNA in conjunctival sac was detected in 21 patients (9%). No relation between presence and the duration of ophthalmic symptoms and SARS-CoV-2 infection detected in conjunctival secretions was found. The tear film concentrations of IFN-γ, TNF-α, IL-5, IL-8 and GM-CSF were found to be significantly greater among patients with positive conjunctival swab results as compared to the group negative for SARS-CoV-2 in conjunctival sac. Our current data depict a group of inflammatory mediators in human tears, which may play a significant role in ocular pathology of SARS-CoV-2 conjunctival infection.

Approach of an Academic Ophthalmology Department to Recovery During the Coronavirus Pandemic

Introduction

A methodology for safe recovery of an ophthalmology department during a pandemic does not currently exist. This study describes successful recovery strategies for an urban, multi-specialty ophthalmology department serving a high-risk patient population.

Methods

The study took place at a large multi-specialty tertiary care academic ophthalmology department in a metropolitan city during a seven-month period (March–October 2020). Five recovery ad hoc committees were charged with formulating metrics and initiatives to manage clinical volumes while maintaining safe practices, providing patient access, and minimizing financial damage. A six-tier system was created to resume non-urgent appointments in May 2020. Educational and research activities were maintained through the development of virtual curricula and research platforms.

Results

The number of clinical and surgical visits per month in 2020 compared to 2019 and the time to reach ≥95% of pre-COVID patient volumes were monitored. In October 2020, ≥95% of pre-COVID volumes were attained (11,975 vs 12,337 patient visits in October 2019; 266 vs 272 surgical cases in October 2019). Despite significant financial losses, the department surpassed December 2019 collections in December 2020. No faculty, staff, or trainees received furloughs or pay cuts. There was no COVID-19 transmission between faculty, staff, and patients.

Discussion

With strategic implementation of recovery strategies following CDC safety measures, it was possible to safely deliver care to patients with urgent and non-urgent eye conditions. Patient volumes were fully recovered in an ambulatory urban healthcare setting within a high-risk COVID-19 population within seven months while educational and research missions were successfully sustained.

Ocular Distribution of the Renin-Angiotensin-Aldosterone System in the Context of the SARS-CoV-2 Pandemic

The COVID-19 pandemic has resulted in an unprecedented impact on global health, economy, and way of life. SARS-CoV-2, the virus responsible for the disease, utilizes the ACE2 receptor found on host cells to mediate entry, replication, and infection. Numerous studies have elucidated the presence of many components of the renin-angiotensin-aldosterone system (RAAS) in the eye, including the ACE2 receptor. Considering this, and the anatomical vulnerability that the exposed ocular surface offers with its interconnectedness to the respiratory system, there is a theoretical risk of pathogen entry from the ocular route as well as the development of COVID-19-associated eye disease. Despite this, the actual epidemiological data demonstrates low ocular symptoms, possibly due to differing ACE2 receptor expression across age, ethnicity, and sex coupled with the protective properties of tears. We summarize the current literature on ocular RAAS with specific focus on the ACE2 receptor and its interplay with the SARS-CoV-2 virus.

Impact of COVID-19 pandemic on ophthalmic presentations to an Australian outer metropolitan and rural emergency department: a retrospective comparative study

Background

To analyse ophthalmic presentations to an outer metropolitan and a rural emergency department (ED) during the first wave of the COVID-19 pandemic in New South Wales (NSW), Australia.

Methods

A retrospective comparative study of ophthalmic emergency presentations to Campbelltown Hospital (fifth busiest NSW metropolitan ED; population 310,000) and Bowral and District Hospital (rural ED; population 48,000) before and during COVID-19 was conducted. Patient demographics, triage category, referral source, diagnosis, length of stay, departure status, and follow-up location were assessed from coding data between March 1st to May 31st in 2019 and 2020, corresponding to the peak case numbers and restrictions during the first wave of the COVID-19 pandemic in NSW. Differences before and during COVID-19 were analysed using chi-squared tests or independent sample t-tests.

Results

There was no change in ophthalmic presentations at Campbelltown (n = 228 in 2019 vs. n = 232 in 2020; + 1.75%, p = 0.12) and an increase at Bowral (n = 100 in 2019 vs. n = 111 in 2020; + 11%, p < 0.01) during COVID-19. Urgent ophthalmic presentations (Triage Category 3) decreased at Bowral (p = 0.0075), while non-urgent ophthalmic presentations (Triage Category 5) increased at both hospitals (Campbelltown p < 0.05, Bowral p < 0.01).

Conclusions

There was no change in the total number of ophthalmic presentations to an outer metropolitan and an increase to a rural ED during the first wave of the COVID-19 pandemic in New South Wales, Australia. A change in the type of ophthalmic presentations at these peripheral EDs suggest that a high demand for ophthalmic services remained despite the pandemic and its associated gathering and movement restrictions. A flexible healthcare delivery strategy, such as tele-ophthalmology, may optimise patient care during and after COVID-19.

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.

Prevalence of SARS-CoV-2 in Conjunctival Swab Samples Among Patients Presenting with Conjunctivitis During the COVID-19 Pandemic

Purpose

To investigate the prevalence of SARS-CoV-2-associated conjunctivitis among patients presenting with conjunctivitis to ophthalmology clinics in the absence of respiratory symptoms suggesting COVID-19 during the first year of the pandemic.

Patients and Methods

This prospective, observational, cross-sectional study enrolled patients aged 18 years and older who presented with acute conjunctivitis between May 2020 and May 2021. After reviewing demographics, ocular and systemic symptoms, a slit lamp examination was performed. Five samples were collected (conjunctival swab from each eye, nasal swab from each nostril, and a nasopharyngeal swab) in separate tubes for a reverse transcription-polymerase chain reaction test for SARS-CoV-2. Patients were called at 1 and 2 weeks to follow up on their ocular and systemic symptoms and collect information about conjunctival adenovirus test results and COVID-19 test results if performed outside of the study.

Results

A total of 36 patients were enrolled. The most common ocular symptom was redness (35/36, 97%), and 14 patients (39%) had symptoms in both eyes at the time of the presentation. SARS-CoV-2 RNA was not detected in any samples collected during the study visit (95% confidence interval [CI] from 0 to 0.08). None of the study participants were diagnosed with COVID-19 following conjunctivitis during the 2-week follow-up period. We found that 25 patients had a conjunctival adenovirus test done on the day of their study visit, 9 of which reported positive results.

Conclusion

Our data suggest that it may not be valuable to obtain routine testing of SARS-CoV-2 in patients presenting with conjunctivitis in the absence of COVID-19.

Air-Liquid-Interface Differentiated Human Nose Epithelium: A Robust Primary Tissue Culture Model of SARS-CoV-2 Infection

The global urgency to uncover medical countermeasures to combat the COVID-19 pandemic caused by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has revealed an unmet need for robust tissue culture models that faithfully recapitulate key features of human tissues and disease. Infection of the nose is considered the dominant initial site for SARS-CoV-2 infection and models that replicate this entry portal offer the greatest potential for examining and demonstrating the effectiveness of countermeasures designed to prevent or manage this highly communicable disease. Here, we test an air-liquid-interface (ALI) differentiated human nasal epithelium (HNE) culture system as a model of authentic SARS-CoV-2 infection. Progenitor cells (basal cells) were isolated from nasal turbinate brushings, expanded under conditionally reprogrammed cell (CRC) culture conditions and differentiated at ALI. Differentiated cells were inoculated with different SARS-CoV-2 clinical isolates. Infectious virus release into apical washes was determined by TCID50, while infected cells were visualized by immunofluorescence and confocal microscopy. We demonstrate robust, reproducible SARS-CoV-2 infection of ALI-HNE established from different donors. Viral entry and release occurred from the apical surface, and infection was primarily observed in ciliated cells. In contrast to the ancestral clinical isolate, the Delta variant caused considerable cell damage. Successful establishment of ALI-HNE is donor dependent. ALI-HNE recapitulate key features of human SARS-CoV-2 infection of the nose and can serve as a pre-clinical model without the need for invasive collection of human respiratory tissue samples.

Ocular and Systemic Complications of COVID-19: Impact on Patients and Healthcare

There is increasing information available about the effects of the SARS-CoV-2 virus on the systemic and ocular health of patients, as well as the effects of delayed health care. This mini-review summarizes the potential complications and treatments of COVID-19. Systemic findings include respiratory illness, risk of thromboembolic events, and neurologic findings. Some patients may develop persistent symptoms even after the infection resolves. Effective treatment options include glucocorticoids, antivirals, interleukin-6 antagonists, monoclonal antibodies, Janus kinase inhibitors and vaccines. Potential ocular findings of COVID-19 include conjunctivitis, cranial nerve palsies, and microvascular changes in the retina; most symptoms resolved over time. During the lockdown periods, teleophthalmology was utilized to triage non-urgent issues; patients who did present to emergency departments tended to have more severe disease with worse visual prognoses. While transient delays in outpatient ophthalmic care may be tolerated in some patients, others experienced significant vision loss with interruptions in treatments. Resumption of ophthalmic care as soon as possible may help mitigate the effects of delayed care due to the pandemic.

Front lines of the COVID-19 pandemic: what is the effectiveness of using personal protective equipment in health service environments?-a systematic review

PURPOSE

This systematic review aimed to evaluate the effectiveness of the use of personal protective equipment (PPE) in closed environments, similar to waiting or exam rooms of healthcare facilities, in the face of exposure to a bioaerosol.

METHODS

Combinations of words were selected for six electronic databases and for the gray literature. To consider the eligibility of the studies to be included/excluded, the acronym "PECOS" was used: humans and/or experimental models that simulate aerosol (Population); aerosol exposure and the use of masks/respirators (exposition/intervention); controlled or not controlled (comparison); effectiveness of PPE and the receiver exposure (outcomes); and randomized clinical studies or not, observational or laboratory simulation studies (Studies design).

RESULTS

A total of 4820 references were retrieved by the search strategy. Thirty-five articles were selected for complete reading, of which 13 articles were included for qualitative synthesis. A surgical mask or N95 respirator reduced the risk of transmission, even over short distances. The use of masks, even those with less filtering power, when used by all individuals in the same environment is more effective in reducing risk than the use of respirators with high filtering power for only some of the individuals present.

CONCLUSION

The use of mask in closed environments is effective in reducing the risk of transmission and contagion of a contaminated bioaerosol, with greater effectiveness when these devices are used by the source and receiver, regardless of the equipment's filtering power. (PROSPERO 2020 CRD 42020183759).

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.

Long-term ocular damage after recovery from COVID-19: lack of evidence at three months

IMPORTANCE

A small number of COVID-19 patients has been reported to suffer from acute keratoconjunctivitis. In very rare cases, acute inflammatory retinal vein occlusion, papillophlebitis or retinopathy have been observed.

OBJECTIVE

To determine possible long-term effects on the eye, especially on the retina, in patients who had suffered from COVID-19 at least 3 months after recovery.

DESIGN

Prospective cross-sectional study.

SETTING

Hospital of the Ludwig Maximilians University, Munich.

PARTICIPANTS

Patients who had been tested positive for SARS-CoV-2 or for anti-SARS-CoV-2 IgG serum antibodies in the Hospital of the Ludwig Maximilians University, Munich between May and September.

METHODS

Patients who had tested positive were either hospitalized or discharged into home quarantine via the emergency room. Three months after recovery, they were invited to participate voluntarily for this study during their follow-up in our clinic. A complete ophthalmological exam including functional and imaging end points (including optical coherence tomography (OCT), OCT angiography) was performed.

MAIN OUTCOMES AND MEASURES

Visual acuity, slit lamp, bio microscopy and fundoscopy, multimodal imaging findings.

RESULTS

In total, 21 patients were examined. The mean age (SD) of the patients was 48.7 (18.3) years. Of these, 14 (66.6%) were hospitalized and 7 (33.3) were discharged home. Two hospitalized patients (9.5%) received invasive ventilation. During the infection, 14 of the 21 patients (66.6%) were in regular care whereas 2 patients (9.5%) received intensive care ventilation for 8.5 (SD) (0.7) days on average in the COVID ICU. Ophthalmological examination of the previously hospitalized group took place 111.4 (23.2) days after recovery and discharge from the hospital, while non-hospitalized patients were examined after mean 123.4 (44.7) days. All patients showed normal findings for anterior and posterior segment of both eyes. OCT and OCT-A showed no evidence of retinal damage, or vascular or microvascular events.

CONCLUSION AND RELEVANCE

This study with a small prospective cohort of 21 patients indicates that there might be no evidence of ocular complications at 3 months after recovery from COVID-19, without previous eye involvement. Further studies with more participants with and without acute ocular symptoms are necessary for final evidence.

Immune dysregulation and system pathology in COVID-19

The coronavirus disease 19 (COVID-19) caused by the novel coronavirus known as SARS-CoV-2 has caused a global public health crisis. As of 7 January 2021, 87,640,402 confirmed cases and 1,891,692 mortalities have been reported worldwide. Studies focusing on the epidemiological and clinical characteristics of COVID-19 patients have suggested a dysregulated immune response characterized by lymphopenia and cytokine storm in these patients. The exaggerated immune response induced by the cytokine storm causes septic shock, acute respiratory distress syndrome (ARDS), and/or multiple organs failure, which increases the fatality rate of patients with SARS-CoV-2 infection. Herein, we review the recent research progress on epidemiology, clinical features, and system pathology in COVID-19. Moreover, we summarized the recent therapeutic strategies, which are either approved, under clinical trial, and/or under investigation by the local or global health authorities. We assume that treatments should focus on the use of antiviral drugs in combination with immunomodulators as well as treatment of the underlying comorbidities.

Dual Corneal-Graft Rejection after mRNA Vaccine (BNT162b2) for COVID-19 during the First Six Months of Follow-Up: Case Report, State of the Art and Ethical Concerns

Present mass vaccination against Coronavirus Disease-19 (COVID-19) is the most widely used health policy and the most promising approach to curb the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic globally. However, new side effects are emerging from the mass vaccination not described during the experimental stages. In the present study, we discuss a case of acute corneal graft rejection, which has occurred 25 years after transplantation and 13 days after the administration of the BNT162b2 vaccine (Comirnaty, BioNTech/Pfizer), which was followed-up for a period of six months. In this period, the corneal inflammation appeared twice but was successfully managed with topical therapy and supplementation of Vitamin D. A risk of corneal graft rejection must be included in the list of potential vaccine complications, in order to inform the transplanted patient to undergo a preliminary and a follow-up ocular examination, and eventually to include corneal graft in the list of contraindications to vaccination.

Retina stem cells, hopes and obstacles

Retinal degeneration is a major contributor to visual dysfunction worldwide. Although it comprises several eye diseases, loss of retinal pigment epithelial (RPE) and photoreceptor cells are the major contributors to their pathogenesis. Early therapies included diverse treatments, such as provision of anti-vascular endothelial growth factor and many survival and trophic factors that, in some cases, slow down the progression of the degeneration, but do not effectively prevent it. The finding of stem cells (SC) in the eye has led to the proposal of cell replacement strategies for retina degeneration. Therapies using different types of SC, such as retinal progenitor cells (RPCs), embryonic SC, pluripotent SCs (PSCs), induced PSCs (iPSCs), and mesenchymal stromal cells, capable of self-renewal and of differentiating into multiple cell types, have gained ample support. Numerous preclinical studies have assessed transplantation of SC in animal models, with encouraging results. The aim of this work is to revise the different preclinical and clinical approaches, analyzing the SC type used, their efficacy, safety, cell attachment and integration, absence of tumor formation and immunorejection, in order to establish which were the most relevant and successful. In addition, we examine the questions and concerns still open in the field. The data demonstrate the existence of two main approaches, aimed at replacing either RPE cells or photoreceptors. Emerging evidence suggests that RPCs and iPSC are the best candidates, presenting no ethical concerns and a low risk of immunorejection. Clinical trials have already supported the safety and efficacy of SC treatments. Serious concerns are pending, such as the risk of tumor formation, lack of attachment or integration of transplanted cells into host retinas, immunorejection, cell death, and also ethical. However, the amazing progress in the field in the last few years makes it possible to envisage safe and effective treatments to restore vision loss in a near future.

The Influence of COVID-19 Lockdown in Jordan on Patients with Diabetic Retinopathy: A Case-Control Study

Background

Diabetic retinopathy (DR) is a leading cause of vision impairment in working-age adults. Patients with DR need extensive follow-ups with timely proper treatment. In Jordan, a complete lockdown was decided during the COVID-19 pandemic including the closure of outpatients' clinic. In this study, we assess the effect of the lockdown on the progression and visual outcome for patients with DR who had interruption in their plan.

Methods

Retrospectively, we identified all patients who were scheduled for procedures for the management of diabetic retinopathy (DR) during the COVID-19-related quarantine period in Jordan from March 16th to June 6th, 2020. All demographics and clinical data, procedure information, and visual outcome were collected. Another control group of patients with similar characteristics who were scheduled for procedures related to DR before the COVID-19 pandemic from October 15th to December 31st, 2019 were included.

Results

One hundred and thirty-seven eyes planned for procedures from 89 patients were included. The case group comprises 56 eyes (40.9%). The mean age of the patients was 61.4 years. The right eye was involved in 69 procedures (50.4%). The mean change in visual acuity for the case group in the procedure eye was 0.176 in LogMAR (drop of almost 9 LogMAR letters) and the mean change in visual acuity for the control group in the procedure eye was -0.103 LogMAR (gain of about 5 LogMAR letters). Also, the central subfield thickness (CST) values were significantly worse in the case group. Furthermore, patients in the case group had significantly more disease progression (new findings and worsening of the already established findings).

Conclusion

Interrupting the important procedures for DR patients and delaying their follow-up may adversely affect their visual outcome. National decisions should consider conducting these procedures and exempt those patients from any lockdown with proper precautions. Moreover, certain measures would be considered, such as treat-and-extend protocol, home screening and portable OCT examination, and newer long-acting anti-VEGF drugs.

Preoperative COVID-19 Testing for Elective Ophthalmological Procedure in a Tertiary Health Care Centre: Our Experience During the Pandemic

Background

To study the prevalence of coronavirus infection among asymptomatic patients requiring eye surgery and the role of screening in prevention of spread of infection among the healthcare workers.

Design

The prospective observational study was conducted in the Ophthalmology department of a tertiary care center in Delhi from September 2020 to December 2020.

Setting

Patients requiring elective ophthalmological procedures in a tertiary care hospital were screened for coronavirus using the RT-PCR method. Testing methods and results were documented.

Results

Among the 218 asymptomatic patients posted for elective surgery in that period, 16 (7.3%) were found to be positive for COVID-19. Those who tested positive were advised home isolation and surgery was postponed for the next 14 days. No complications were reported in these patients. One health-care worker also tested positive for COVID-19 during our study period.

Conclusion

In our study, 1 out of 14 asymptomatic patients were found to be carriers for the novel virus. Asymptomatic COVID-infected patients may lead to transmission of the virus inside the hospital among the visiting patients and hospital staff while they have no adverse effect on the surgery and its outcome.

Combined endophthalmitis and orbital cellulitis in patients with corona virus disease (COVID-19)

Purpose

To document the presentation of unilateral combined endophthalmitis and orbital cellulitis in patients with COVID-19 infection and study their prognosis.

Patients and methods

This interventional case series study included 9 patients referred to the Ophthalmology Department, Minia University Hospital with unilateral combined endophthalmitis and orbital cellulitis between April 2020 and March 2021. In addition to the COVID-19 work-up, all patients were subjected to full ophthalmological evaluation and managed according to their ophthalmic and systemic disease.

Results

The patients were 5 females and 4 males. They had clinical, laboratory and imaging findings that confirmed COVID-19 infection. All patients had unilateral endophthalmitis with orbital cellulitis and profound visual loss in the affected eye. Three patients died due to respiratory failure, while 6 patients recovered systemically. The survived patients developed atrophia bulbi in 4 patients and in 2 patients, the globe retained normal size but with complete visual loss.

Conclusion

Combined endophthalmitis and orbital cellulitis can be one of the early presentations of patients with COVID-19 infection with poor visual prognosis.

Trial registration

Clinical registration: clinicaltrials.gov identifier: NCT04456556.

The Impact of Three Waves of the COVID-19 Pandemic on the Characteristics of Primary Rhegmatogenous Retinal Detachments at a Tertiary Referral Centre

Purpose

This study assessed the effect of three waves of the COVID-19 pandemic primarily on the number and timing of referrals due to rhegmatogenous retinal detachment (RRD) and secondarily on the demographic or clinical characteristics of patients.

Patients and Methods

A retrospective single-centre analysis of medical records included 247 eyes from 247 patients who underwent primary RRD repair with (phaco) vitrectomy between January 1, 2019, and May 31, 2021.

Results

The percentage of referrals due to primary RRD during the first year of pandemic (March 2020–February 2021) was 16.5% (p=0.179) lower than a year earlier. The percentage of referrals during the first, second and third wave of the pandemic was 48.4%, 18.5% and 26.1% (p=0.029, 0.475, 0.343) lower than in the corresponding months of 2019. A rebound effect was observed only after the first wave. The numbers of referrals in April and May 2021 were similar as in the corresponding months of 2019. No significant differences were observed in the demographic and clinical characteristics of patients admitted before and during the COVID-19 pandemic, other than a tendency towards a higher representation of women, younger persons, longer duration of symptoms but better visual acuity in the latter group. Silicone oil tamponade was used more frequently during the pandemic than before.

Conclusion

In this study, the COVID-19 pandemic affected the number and timing of referrals due to RRD and the clinical but not demographic characteristics of the patients. The effect lessened with the duration of the pandemic. Previously raised concerns regarding the delay in RRD referrals may no longer be valid during a potential fourth wave of the pandemic. The impact of the pandemic’s waves should be analysed separately, as such an approach provides a better insight into the fluctuations in the number of referrals due to RRD than a year-to-year comparison.

Ocular Manifestations of Post-Acute COVID-19 Syndrome, Upper Egypt Early Report

Purpose

To evaluate the ocular manifestations of post-acute COVID-19 syndrome.

Methods

A retrospective, comparative study included 100 patients who had recovered from COVID-19 and 100 controls who were recruited by stratified randomization from hospital registration system and analyzed regarding history, full ophthalmological examination, general examination including internal medicine and neurological evaluation. Laboratory tests were done.

Results

Mean±SD of age were 55.5 ± 6.2 in COVID group vs 56.5 ± 5.8 in control group; P value = 0.7. In COVID group, 57 patients (57%) were males vs 51 patients (51%) in control group (P value = 0.39), the other compared parameters including history and risk factors showed non-significant difference except for ESR and D-dimer which were elevated in COVID group. In COVID group, 5 patients (5%) were having retinal vascular occlusion, 2 patients (2%) were having anterior ischemic optic neuropathy AION, 3 patients (3%) were having uveitis and 2 patients (2%) were having central serous chorioretinopathy CSCR. While in control group, 2 patients (2%) were having retinal vascular occlusion, and none had AION, uveitis or CSCR (P value = 0.006).

Conclusion

Post-acute COVID-19 syndrome could affect the eyes in the form of coagulation problems, neurological morbidities, and other manifestations. This necessitates meticulous follow-up of recovered patients from COVID-19.

A Narrative Review of Current Understanding and Classification of Dry Eye Disease with New Insights on the Impact of Dry Eye during the COVID-19 Pandemic

Dry eye disease (DED) is a complex, progressive and multifactorial condition that is commonly seen in clinical practice and can be challenging to accurately diagnose. Untreated or suboptimally managed dry eye can progress to severe, chronic disease which may become resistant to treatment. Symptoms include ocular irritation and visual impairment. Patients frequently report negative consequences regarding quality of life (QoL), productivity and psychological wellbeing. Certain lifestyle factors (e.g. use of screen-based devices, air conditioning) can induce or exacerbate symptoms of DED, leading to progressive and debilitating complications. Exposures to such triggers are likely to have increased significantly during the ongoing COVID-19 pandemic with people across the globe living with heightened levels of stress/anxiety while being forced to adapt most aspects of their daily lives (from work and education through to social activities) to accommodate social distancing, primarily through the use digital technologies. This review aims to provide a concise and practical overview of current understanding regarding DED, highlighting proposals for refined diagnostic categories and therapeutic terminologies that are designed to improve identification and management of dry eye as well as reduce or slow disease progression. Finally, the findings of a European survey are shared to illustrate the impact of the COVID-19 pandemic on the lives of people with DED. The survey was conducted during the first lockdown period (March–September 2020) and explored issues relating to psychological wellbeing, QoL and engagement with healthcare services. The results demonstrate the ways in which the pandemic amplified the impact of dry eye on daily life and may be valuable in enhancing understanding among clinicians of the challenges faced by people with DED, which extend beyond the signs and symptoms of disease.

Keep Eyes on COVID-19: Ophthalmic Symptoms and Potential Transmission of SARS-CoV-2 through the Oculus

In December 2019, a new coronavirus disease 2019 (COVID-19) emerged and rapidly spread globally, posing a worldwide health emergency. The pathogen causing this pandemic was identified as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It is well known that SARS-CoV-2 transmits via respiratory droplets and close contact with infected individuals or contaminated items. In addition to these two major transmission routes, other modes of transmission have not been confirmed. Considering that some COVID-19 patients have presented with ocular discomforts and positive SARS-CoV-2 RNA in ocular surfaces, as well as the discovery of the SARS-CoV-2 receptors, angiotensin-converting enzyme 2, and transmembrane protease, serine 2, in the oculus, the ocular surface is now thought to be a possible alternative route of SARS-CoV-2 transmission and a replication site. This review summarizes the evidence connecting COVID-19 with ocular tissues, ocular symptoms during SARS-CoV-2 infection, the potential role of the conjunctiva in SARS-CoV-2 transmission, and the physiopathological mechanisms. Appropriate precautions in ophthalmology departments, including innovative complete and effective patient management plans, protective personal equipment, hand hygiene, and strict personal distance intervals, are essential to effectively minimize the spread of SARS-CoV-2 and control the pandemic.

Testing the Sensitivity of Conjunctival Swabs from Confirmed COVID-19 Patients

Objective

To investigate the incidence of COVID-19 viral RNA in the conjunctiva of patients priorly confirmed to have COVID-19, using a conjunctival swab and to determine swab sensitivity.

Methods

This cross-sectional study enrolled patients who tested positive for COVID-19 with PCR via nasopharyngeal swabs. Conjunctival swabs were collected for each patient and subjected to RT-PCR assay. Demographic data and clinical history of patients were investigated and analysed.

Results

In this study, 4.9% of the patients tested positive with conjunctival swabs for COVID-19; 29.9%, 28.7%, 20.1%, and 12.2% of the patients had fever, shortness of breath, cough, and red eye, respectively. Among all patients, 18.9% and 73.2% had a history of traveling and contact with positive COVID-19 cases, respectively. There were significant correlations between the conjunctival results and diabetes (P=0.049) and hypertension (P=0.002). Traveling was a risk factor for positive conjunctival swab testing (P=0.016). The sensitivity of the conjunctival swab was 4.8%.

Conclusion

Among all positive cases of COVID-19, a small percentage had positive results when tested using a conjunctival swab. Conjunctival swabs have very low sensitivity for the detection of COVID-19. However, tears could still be a mode of disease transmission, especially from patients to eye care specialists.

ACE2-Independent Interaction of SARS-CoV-2 Spike Protein with Human Epithelial Cells Is Inhibited by Unfractionated Heparin

Coronaviruses such as SARS-CoV-2, which is responsible for COVID-19, depend on virus spike protein binding to host cell receptors to cause infection. The SARS-CoV-2 spike protein binds primarily to ACE2 on target cells and is then processed by membrane proteases, including TMPRSS2, leading to viral internalisation or fusion with the plasma membrane. It has been suggested, however, that receptors other than ACE2 may be involved in virus binding. We have investigated the interactions of recombinant versions of the spike protein with human epithelial cell lines that express low/very low levels of ACE2 and TMPRSS2 in a proxy assay for interaction with host cells. A tagged form of the spike protein containing the S1 and S2 regions bound in a temperature-dependent manner to all cell lines, whereas the S1 region alone and the receptor-binding domain (RBD) interacted only weakly. Spike protein associated with cells independently of ACE2 and TMPRSS2, while RBD required the presence of high levels of ACE2 for interaction. As the spike protein has previously been shown to bind heparin, a soluble glycosaminoglycan, we tested the effects of various heparins on ACE2-independent spike protein interaction with cells. Unfractionated heparin inhibited spike protein interaction with an IC₅₀ value of <0.05 U/mL, whereas two low-molecular-weight heparins were less effective. A mutant form of the spike protein, lacking the arginine-rich putative furin cleavage site, interacted only weakly with cells and had a lower affinity for unfractionated and low-molecular-weight heparin than the wild-type spike protein. This suggests that the furin cleavage site might also be a heparin-binding site and potentially important for interactions with host cells. The glycosaminoglycans heparan sulphate and dermatan sulphate, but not chondroitin sulphate, also inhibited the binding of spike protein, indicating that it might bind to one or both of these glycosaminoglycans on the surface of target cells.

ACE2-Independent Interaction of SARS-CoV-2 Spike Protein with Human Epithelial Cells Is Inhibited by Unfractionated Heparin

Coronaviruses such as SARS-CoV-2, which is responsible for COVID-19, depend on virus spike protein binding to host cell receptors to cause infection. The SARS-CoV-2 spike protein binds primarily to ACE2 on target cells and is then processed by membrane proteases, including TMPRSS2, leading to viral internalisation or fusion with the plasma membrane. It has been suggested, however, that receptors other than ACE2 may be involved in virus binding. We have investigated the interactions of recombinant versions of the spike protein with human epithelial cell lines that express low/very low levels of ACE2 and TMPRSS2 in a proxy assay for interaction with host cells. A tagged form of the spike protein containing the S1 and S2 regions bound in a temperature-dependent manner to all cell lines, whereas the S1 region alone and the receptor-binding domain (RBD) interacted only weakly. Spike protein associated with cells independently of ACE2 and TMPRSS2, while RBD required the presence of high levels of ACE2 for interaction. As the spike protein has previously been shown to bind heparin, a soluble glycosaminoglycan, we tested the effects of various heparins on ACE2-independent spike protein interaction with cells. Unfractionated heparin inhibited spike protein interaction with an IC50 value of <0.05 U/mL, whereas two low-molecular-weight heparins were less effective. A mutant form of the spike protein, lacking the arginine-rich putative furin cleavage site, interacted only weakly with cells and had a lower affinity for unfractionated and low-molecular-weight heparin than the wild-type spike protein. This suggests that the furin cleavage site might also be a heparin-binding site and potentially important for interactions with host cells. The glycosaminoglycans heparan sulphate and dermatan sulphate, but not chondroitin sulphate, also inhibited the binding of spike protein, indicating that it might bind to one or both of these glycosaminoglycans on the surface of target cells.

The Implications of COVID-19 to Ophthalmology

The coronavirus disease 2019 (COVID-19) pandemic has brought unprecedented challenges to ophthalmology. At least 16 ophthalmologists worldwide have succumbed to COVID-19. It reflects the susceptibility of ophthalmologists to COVID-19 infection as they are in close proximity to patients. This chapter provides an overview of the ocular manifestations of COVID-19, risks of COVID-19 to ophthalmologists and patients, clinical service adjustments due to COVID-19, and infection control measures to minimize the transmission of COVID-19 in ophthalmic practice.

Evaluation of Anti-SARS-CoV-2 IgA in the Conjunctival Secretions of COVID-19 Patients

Purpose

To assess the presence of anti-SARS-CoV-2 IgA in the conjunctival secretions of confirmed COVID-19 patients by nasopharyngeal swabs and correlate its presence with the severity of the disease, patient's age, sex and ocular symptoms.

Methods

This study included 44 positive COVID-19 patients confirmed with nasopharyngeal swabs during the period 17-28 February 2021 at Sohag Tropical Medicine Hospital. Tears and conjunctival secretions were examined for the presence of anti-SARS-CoV-2 IgA.

Results

While non-reactive results are strongly correlated to low titre and vice versa, severity showed significant correlation with neither IgA reactivity nor titre. Meanwhile, IgA reactivity did not show significant correlation with either age or sex. The reactivity and IgA titre are correlated with ocular symptoms.

Conclusion

The anti-SARS-CoV-2 IgA could be found in ocular secretions in SARS-CoV-2 patients. There is no correlation with age or sex or severity of the disease; however, they are correlated with ocular symptoms.

The Impact of COVID-19 on Acute and Elective Corneal Surgery at Moorfields Eye Hospital London

Purpose

Moorfields Eye Hospital sits as a major tertiary centre for ophthalmic care in the United Kingdom and became a central hub to provide safe and effective ophthalmic care across London and surrounding regions during the COVID-19 pandemic. We explore the impact on both the acute and elective corneal services during the first wave of this pandemic.

Methods

A retrospective review of the proportion of corneal transplants and anterior segment trauma repairs was performed during the period of March 23rd to July 1st 2020 compared with an identical period in 2019. Data were acquired from our in-house electronic patient records.

Results

A 92% reduction in corneal elective work was observed during the lockdown period compared with an identical period in 2019, with only 10 elective cases in total being performed. In addition, 91 corneal cross-linking and 76 therapeutic lasers were cancelled. There were 15 cases of primary repair for anterior segment trauma compared with 6 cases pre-COVID-19. A similar scenario occurs with removal of foreign body (4 cases during COVID-19 period versus no cases during pre-COVID-19 era) and with traumatic lens aspirations (6 cases during COVID-19 compared with 2 pre-COVID-19). Interestingly, a statistical difference (p=0.03) was found in the time interval from presentation of symptoms to emergency corneal surgery. During the COVID-19 period, a delay of 1.5 days ± 2.29 (range 0–10 days) occurred compared with 0.8 days ± 1.54 (range 0–6 days) pre-COVID-19.

Conclusion

Stringent risk stratification reduced elective corneal surgery capacity during the lockdown thereby preserving social distancing requirements. However, an apparent increase in emergency corneal surgery seen is likely attributed to centralisation of ophthalmic services during the pandemic crisis, alongside increased domestic injuries. Despite the challenges posed, successful delivery of corneal surgery occurred whilst helping to identify lessons in preparations for future pandemics and current inefficiencies in healthcare delivery.

An Eye on COVID-19: A Meta-analysis of Positive Conjunctival Reverse Transcriptase-Polymerase Chain Reaction and SARS-CoV-2 Conjunctivitis Prevalence

SIGNIFICANCE

This analysis and review demonstrate that, although emerging data indicate that the prevalence of severe acute respiratory coronavirus 2 (SARS-CoV-2) on the ocular surface and coronavirus disease 2019 (COVID-19) conjunctivitis is rare, the ocular surface remains of interest as a potential inoculation and transmission site for SARS-CoV-2. Continued safety precautions should be taken as more data become available.COVID-19, caused by SARS-CoV-2, is a novel, global pandemic that has infected millions and, up to this point, caused more than two million fatalities worldwide. The ocular surface has become of interest as a possible vector for transmission by acting as a direct inoculation site, being a conduit for the virus into the respiratory system or as a method of transmission from potentially infected conjunctiva or tears. The components necessary for SARS-CoV-2 to theoretically infect ocular tissues are present: binding receptors (angiotensin-converting enzyme 2 and cluster of differentiation 147) and mechanisms for cell entry (transmembrane protease serine 2 and cathepsin L). This meta-analysis of COVID-19 prevalence data indicates that SARS-CoV-2 RNA has been infrequently found in conjunctival samples when tested with reverse transcriptase-polymerase chain reaction. This review estimates the prevalence of SARS-CoV-2 on the ocular surface and prevalence of conjunctivitis in patients with laboratory-confirmed COVID-19. There is much to be learned regarding ocular tropism of SARS-CoV-2.

COVID-19: risk of ocular transmission in health care professionals

Introduction:

The current pandemic of severe acute respiratory symptom coronavirus 2 (SARS-CoV-2) has had a major impact on individuals’ lives. Social isolation and the use of personal protective equipment - the latter being especially important for health care workers - emerged as two of the main methods of preventing the spread of the disease. The eye can represent a source of transmission through contaminated tears, as well as a source of infection for respiratory droplets or aerosol particles, which may come into contact with the ocular surface and migrate to the lungs and other parts of the body.

Objectives:

To investigate the risk of ocular transmission through a literature review and identify ways of preventing it.

Methods:

A search of the scientific literature was conducted in the PubMed and Cochrane databases, using a combination of the following keywords: “COVID-19,” “eye,” “personal protective equipment,” “SARS-CoV-2,” “protective goggles,” “face shields,” and “workers’ health.”

Results:

The mechanisms of ocular transmission have not been fully elucidated, but studies have demonstrated the presence of viral RNA in the conjunctival sac and aerosolized secretions of contaminated patients; these droplets may come into contact with the eyes of uninfected bystanders, entering the respiratory system through the nose and gaining access to the lungs.

Conclusions:

Studies show that the virus can be effectively transmitted through the eyes, underscoring the importance of protective goggles for health care workers or potential transmitters of the virus, in addition to the need for additional education measures to encourage hand hygiene and discourage touching of the eyes.

The "Quarantine Dry Eye": The Lockdown for Coronavirus Disease 2019 and Its Implications for Ocular Surface Health

The pandemic of coronavirus disease 2019 (COVID-19) has led many countries of the world to impose a series of containment measures such as lockdowns (mass quarantines), curfews or similar restrictions (eg, stay-at-home orders, or shelter-in-place orders). All these restrictions were established in order to limit spread of COVID-19. Thus, approximately 3.9 billion people worldwide were under lockdown by early April 2020. During this time (home confinement), some solutions have been proposed by experts to improve work and school productivity, including smart working and online school lessons. However, many of the restrictive measures are likely to act as predisposing factors for dry eye disease (DED), directly or related to sick building syndrome (SBS). Herein, we discuss the implications of quarantine measures on eye health, in particular on DED associated with SBS, and introduce some potential preventive strategies for lockdown-related ocular surface disorders. Several risk factors are implicated in their pathogenesis, including environmental changes (eg, air quality) and modifications in personal behaviors (eg, the abuse of digital devices, malnutrition, and sleep/psychiatric disorders). Considering a number of predisposing factors for DED, it is possible to state that patients under lockdown are at risk of ocular surface alterations. Accordingly, the COVID-19 pandemic era is expected to determine an increase in dry eye patients all around the world (a new phenomenon that we propose to name the "quarantine dry eye") in the event that the restrictive measures will be recursively extended over time.

The Transmission of SARS-CoV-2 Infection on the Ocular Surface and Prevention Strategies

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a global health problem. Although the respiratory system is the main impaired organ, conjunctivitis is one of its common findings. However, it is not yet understood if SARS-CoV-2 can infect the eye and if the ocular surface can be a potential route of SARS-CoV-2 transmissions. Our review focuses on the viral entry mechanisms to give a better understanding of the interaction between SARS-CoV-2 and the eye. We highlighted findings that give evidence for multiple potential receptors of SARS-CoV-2 on the ocular surface. Additionally, we focused on data concerning the detection of viral RNA and its spike protein in the various ocular tissues from patients. However, the expression level seemed to be relatively low compared to the respiratory tissues as a result of a unique environment surrounding the ocular surface and the innate immune response of SARS-CoV-2. Nevertheless, our review suggests the ocular surface as a potential route for SARS-CoV-2 transmission, and as a result of this study we strongly recommend the protection of the eyes for ophthalmologists and patients at risk.

COVID-19 and conjunctivitis: a meta-analysis

COVID-19 is a disease first identified in Wuhan City, Hubei Province, China, in December 2019, causes by a SARS-COV-2 virus infection. By 27 October 2020, 43,921,473 confirmed cases were reported worldwide, with 1,166,389 COVID-19 deaths. Conjunctivitis has been reported in adults and pediatric patients with COVID-19.

In the eye of the storm: SARS-CoV-2 infection and replication at the ocular surface?

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) first emerged in December 2019 and spread quickly causing the coronavirus disease 2019 (COVID‐19) pandemic. Recent single cell RNA‐Seq analyses have shown the presence of SARS‐CoV‐2 entry factors in the human corneal, limbal, and conjunctival superficial epithelium, leading to suggestions that the human ocular surface may serve as an additional entry gateway and infection hub for SARS‐CoV‐2. In this article, we review the ocular clinical presentations of COVID‐19 and the features of the ocular surface that may underline the overall low ocular SARS‐CoV‐2 infection. We critically evaluate the studies performed in nonhuman primates, ex vivo organ culture ocular models, stem cell derived eye organoids and the differences in infection efficiency observed in different parts of human ocular surface epithelium. Finally, we highlight the additional work that needs to be carried out to understand the immune response of the ocular surface to SARS‐CoV‐2 infection, which can be translated into prophylactic treatments that may be applied to other organ systems.

COVID-19 in the light of current clinical eye research

COVID-19 is a disease caused by a SARS-CoV-2 virus infection first reported in Wuhan city, Chinese province of Hubei, in December 2019. Previously known as 2019 Novel Coronavirus (2019-nCoV) respiratory disease, COVID-19 was declared official name by the World Health Organization (WHO) as COVID-19 in February 2020. By July 2nd, 2020 10,818,005 confirmed cases with 519,467 COVID-19 deaths worldwide. The aim of this review article is to inform the audience of what is available in the current literature on how COVID-19 affects the eyes in adults, children, and elderly. PubMed search was used between December 2019 and July 2nd, 2020. Randomized trials, observational studies, case series or case reports, and letters of research, letters to editors were selected for confirmed cases of COVID-19. According to current scientific literature since the outbreak in December 2019 there have been 218 papers written. Conjunctivitis and keratoconjunctvitis have been reported in adults with COVID-19. Further studies are needed in children and geriatric patients.