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

Posterior segment manifestations and imaging features post-COVID-19

Background

To report the posterior segment (uvea and retinal) manifestations and imaging characteristics of eyes of patients with and after coronavirus disease 2019 (COVID-19).

Methods

We searched the PubMed/MEDLINE database to identify relevant articles using the following search terms: COVID-19, SARS-CoV-2, retina, uvea, optic nerve, retinal findings, posterior segment manifestations, and endophthalmitis. Articles published from December 1, 2019, to May 30, 2021, and indexed in PubMed/ MEDLINE were screened.

Results

For the purpose of this review, we included clinical features of 26 case reports and 8 case series. The posterior segment manifestations reported included cotton wool spots, retinal hemorrhages, central serous retinopathy, papillophlebitis, optic neuritis, panuveitis, multifocal retinitis, necrotizing retinitis, central retinal artery/vein occlusion, and Purtschner like retinopathy. In this review, we have also included optical coherence tomography angiography (OCTA) features that have been described in COVID-19 patients with pneumonia.

Conclusions

COVID-19 patients can experience uveo-retinal manifestations even after recovery. These patients, even if asymptomatic for eye symptoms, should undergo an eye evaluation to rule out posterior segment involvement. OCTA performed in these patients revealed microvascular changes in the superficial and deep retinal plexuses. Some of these patients may require anticoagulant or antiplatelet therapy.

Detection of COVID-19 in tears of ICU-admitted patients with SARS-CoV-2 infection

Purpose

Upon the outbreak of 2019, novel coronavirus (COVID-19) pandemic confirmed the cases surpassed 20 million. Despite a few reports identified the association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with ocular manifestations, it may assess the ocular symptoms of patients with the COVID-19 by ophthalmologists facilitate the diagnosis and prevent transmission.

Methods

A total of 60 patients with the COVID-19 admitted to Baghiatallah hospital from March 2020 to May 2020 were retrospectively reviewed and analyzed for the ocular manifestations, blood tests, and reverse transcriptase-polymerase chain reaction (RT-PCR) for SARS-CoV-2 using nasopharyngeal and conjunctival swabs.

Results

Among 60 included patients with clinically confirmed COVID-19, the median age 58.36 years (IQR: 30–88 years), 27 (45%) were male. Furthermore, 29 (48%) and 5 (8%) patients yielded positive for SARS-CoV-2 on RT-PCR from nasopharyngeal swabs and conjunctival specimens, respectively. Among 60 patients, 10 (16%) and 3 (5%), respectively, had the ocular manifestations and positive results for SARS-CoV-2 on RT-PCR from conjunctival and nasopharyngeal swabs.

Conclusion

Although the positive rate of tear RT-PCR rate is not noticeable as nasopharyngeal swabs yet, COVID-19 transmission through the eyes is biologically plausible.

Vogt-Koyanagi-Harada Disease Following COVID-19 Infection

A 29-year-old female presented to the emergency clinic with gradual visual disturbance in both eyes for 15 days duration, accompanied by bilateral tinnitus, and ocular pain that increased with ocular movements. One month prior to presentation, the patient had tested positive for severe acute respiratory syndrome coronavirus-2 but without complications. Visual acuity was 20/100 in the right eye and 20/300 in the left eye. Funduscopy demonstrated optic nerve swelling, radial nerve fiber striation disruption, and bilateral retinal folds. Optical coherence tomography showed serous (bacillary) retinal detachment and multifocal areas of hyper-reflective changes in the inner and outer plexiform layer with inner nuclear layer thickening and disruption of the interdigitation zone bilaterally. We present a case of incomplete Vogt-Koyanagi-Harada disease following COVID-19 infection.

Evaluation of Reinfection in COVID-19 Patients in the World: A Narrative Review

Background: The evaluation of reinfection and the genetic structure of all human and virus genomes could help to develop programs and protocols for providing services and ultimately to prevent the disease by producing more effective vaccines. Therefore, the aim of this study was to investigate the presence and occurrence of COVID-19 reinfection through a narrative review study. Methods: We searched the Medline (PubMed), Embase, Scopus, Web of Science, Cochrane library, Ovid, and CINHAL databases. Inclusion criteria included all studies whose main purpose was to provide information about the occurrence or presence of reinfection in patients with COVID-19. An independent samples t test was used to compare the continuous outcomes between the 2 groups. Results: The mean duration of the first episode in the group with mild or moderate COVID-19 was 24.42±1.67 days, and it was 21.80±3.79 days in the group with severe COVID-19. The mean duration of the second episode (reinfection) in patients with mild or moderate form was 15.38 ± 5.57 days, and it was 19.20±2.98 days in patients with severe form. In both episodes, the duration of the disease did not significantly differ between the 2 groups (p=0.484 in the first episode; p=0.675 in the second episode), but the interval to the occurrence of reinfection in patients with the mild or moderate form was significantly longer than those with the severe form (p<0.001). In this instance, the time interval in patients with the mild or moderate form was 36.63±5.71 days while in those with the severe form of the disease it was 29.70±5.65 days. Besides, the genomes of the viruses isolated from the first and second episode were different. Conclusion: According to the results, all patients should be very careful about the severity of the second episode because of the more need for medical interventions for saving the patients. The interval between the first end and the second episode as well as the duration of each episode is highly important for better management of the disease.

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

Purpose

The purpose of this study is to assess for histopathological changes within the retina and the choroid and determine the long-term sequelae of the SARS-CoV-2 infection.

Methods

Eyes from seven COVID-19-positive and six similar age-matched control donors with a negative test for SARS-CoV-2 were assessed. Globes were evaluated ex vivo with macroscopic, SLO and OCT imaging. Macula and peripheral regions were processed for Epon embedding and immunocytochemistry.

Results

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

Conclusions

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

Supplementary Information

The online version contains supplementary material available at 10.1007/s00417-021-05460-1.

Recent Advances of COVID-19 Modeling Based on Regenerative Medicine

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has caused a pandemic since December 2019 that originated in Wuhan, China. Soon after that, the world health organization declared Coronavirus disease-2019 a global health concern. SARS-CoV-2 is responsible for a lethal respiratory infection as well as the involvement of other organs due to its large tropism spectrum such as neurologic, cardiovascular, endocrine, gastrointestinal, and renal systems. Since the behavior of the virus is not fully understood, a new manifestation of the infection is revealed every day. In order to be able to design more efficient drugs and vaccines to treat the infection, finding out the exact mechanism of pathogenicity would be necessary. Although there have been some big steps toward understanding the relevant process, there are still some deficiencies in this field. Accordingly, regenerative medicine (RM), can offer promising opportunities in discovering the exact mechanisms and specific treatments. For instance, since it is not always possible to catch the pathophysiology mechanisms in human beings, several modeling methods have been introduced in this field that can be studied in three main groups: stem cell-based models, organoids, and animal models. Regarding stem cell-based models, induced pluripotent stem cells are the major study subjects, which are generated by reprogramming the somatic stem cells and then directing them into different adult cell populations to study their behavior toward the infection. In organoid models, different cell lines can be guided to produce a 3D structure including liver, heart, and brain-like platforms. Among animal models, mice are the most common species in this field. However, in order for mice models to be permissive to the virus, angiotensin-converting enzyme 2 receptors, the main receptor involved in the pathogenicity of the virus, should be introduced to the host cells through different methods. Here, the current known mechanism of SARS-CoV-2 infection, different suggested models, the specific response toward different manipulation as well as challenges and shortcomings in each case have been reviewed. Finally, we have tried to provide a quick summary of the present available RM-based models for SARS-CoV-2 infection, as an essential part of developing drugs, for future therapeutic goals.

Impact of the COVID-19 Pandemic on Refractive Surgery

Purpose of Review

In this article, we review the impact of the COVID-19 pandemic on refractive surgery.

Recent Findings

COVID-19 infection frequently causes eye symptoms, most commonly conjunctivitis or mild irritation. While virus can be detected in tears of symptomatic patients, the risk of transmission via this route appears low.

Summary

Refractive surgery consultations were significantly reduced during the pandemic; however, volume is rebounding quickly likely due to a number of lifestyle, health, and financial factors. Laser refractive and intraocular surgery likely confer a low risk of virus spread, especially in asymptomatic patients. Screening prior to the refractive consultation and surface disinfection in the clinic and operating room can help reduce transmission risk further.

[Ophthalmological manifestations of post-COVID-19 syndrome]

The review presents data on damage to the organ of vision in patients recovered from the new coronavirus infection reflecting on the results obtained by various researchers from examining patients with varying severity of the disease, both during the active stage and after recovery. Possible ways of transmission of the infectious agent into the organ of vision were analyzed. The most common ocular manifestation of COVID-19 is conjunctivitis, while lesions of the retina and optic nerve were noted less often. The article also outlines the strategy for treatment and describes infection prevention measures for doctors and patients.

COVID-19 and the Eye: Ocular Manifestations, Treatment and Protection Measures

The novel pandemic coronavirus disease 2019 (COVID-19) leading to health and economic problems worldwide is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although COVID-19 mainly occurs as a lower respiratory tract infection, there is multiorgan involvement in infected patients. The disease is transmitted from person to person through air droplets or contact with contaminated surfaces. SARS-CoV-2 leads to this systemic involvement by attaching to angiotensin-converting enzyme 2 (ACE2) receptors located on several human cells. Since SARS-CoV-2 RNA has been found in tears of infected patients, ocular surface may allow the virus to transmit to nasopharynx via the nasolacrimal duct. This narrative review aims to sum up all segmental ocular complications, ocular adverse effects of COVID-19 treatment, and preventive measures suggested to minimize the SARS-CoV-2 transmission between patients and ophthalmologists by reviewing currently available literature.

Macular vessel density reduction in patients recovered from COVID-19: a longitudinal optical coherence tomography angiography study

Background/aims

To quantify the longitudinal changes of the macular microvasculature and the foveal avascular zone (FAZ) parameters in patients recovered from coronavirus disease-2019 (COVID-19) using optical coherence tomography angiography (OCTA) analysis.

Methods

This observational, longitudinal study was performed on patients recovered from COVID-19. The OCTA images were recorded at baseline and after 1 and 3 months at the follow-up examination. Vessel density (VD) of the retinal superficial (SCP) and deep capillary plexus (DCP), as well as the area of the FAZ of patients who had recovered from COVID-19, were measured.

Results

In total, 36 eyes of 18 patients (62.2% female) with a mean age of 34.5 ± 7.5 years old were included. Regarding SCP, while the VDs of the whole image, fovea, and parafovea were comparable at different time points, the mean VDs in inferior hemifield, as well as superior and inferior regions of perifovea, underwent significant reductions at month 3, compared to the baseline. In DCP, the mean of VD in the whole image was 54.3 ± 2.7 at the first visit which significantly decreased to 52.1 ± 3.8(P = 0.003) and 51.4 ± 2.7(P = 0.001) after 1 and 3 months, respectively. The VDs in all regions of parafovea and perifovea revealed a significant reduction after 1 and 3 months, compared to the first visit. The mean FAZ area was 0.27 ± 0.08 mm², 0.26 ± 0.08 mm², and 0.27 ± 0.08 mm² at the baseline, month 1, and month 3, respectively (P > 0.05).

Conclusion

Based on the results, the patients who had recovered from COVID-19 had a progressive decrease of VD at the follow-up visit 3 months after COVID-19 infection.

Evaluation of choroidal thickness in patients who have recovered from COVID-19

Purpose

We aimed to evaluate choroidal thickness (CT) in patients who have recovered from COVID-19 by using enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

We included fifty-eight patients who have recovered from COVID-19 (group 1) and fifty healthy control subjects (group 2) in this prospective study. Best corrected visual acuity, anterior segment and posterior segment examinations of all subjects were performed. CT scan and measurements were taken with the EDI mode of the Spectral Domain OCT device.

Results

Of the 108 subjects included in this study, 57 were female and 51 were male. The mean age was similar in both groups (36.10 ± 7.12 and 35.58 ± 7.29, respectively, p = 0.276). Group 1 had the following characteristics: the mean time since diagnosis was 53.18 ± 2.84; it had been 38.48 ± 4.07 days since the PCR test was negative; and all subjects were outpatients. It was detected that the CT of the patients in group 1 decreased in all areas compared to group 2, and this decrease was significant in subfoveal, temporal and inferior areas (257.48 ± 32.79, 273.62 ± 45.04, p = 0.04; 232.96 ± 41.79, 252.76 ± 46.09, p = 0.02, and 245.22 ± 44.58, 271.54 ± 55.07, p = 0.01, respectively). In the retinal nerve fiber layer analysis for group 1, thickening was detected in all areas, although it was not statistically significant, except in the temporal area where it was (superotemporal, superonasal, nasal, inferonasal, inferotemporal, temporal, and global [p = 0 .08, p = 0.45, p = 0.73, p = 0.64, p = 0.74, p = 0.02, and p = 0.10, respectively]).

Conclusion

For individuals who had recovered from COVID-19, it was found that CT decreased in all areas in these patients. Therefore, this study in which we have demonstrated the decrease in the thickness of the choroidal tissue, a tissue with high blood flow, may contribute to the understanding of the systemic microvascular waste of this disease.

COVID-19 positivity rate in corneal tissue donors - A cause for concern!

Purpose

To determine the postmortem positivity for COVID-19 among voluntary eye donors who had been certified to have died of non-COVID-19 causes.

Methods

All donors who donated their corneas (from March 2021 onward) were assessed for COVID-19 positivity tested by nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR) test. Relevant screening history was taken prior to collection. Strict precautions were taken during the retrieval as per the guidelines issued by the National Program for Control of Blindness and Visual Impairment and the Eye Bank Association of India, and the tissues were handled as per standard operating protocol.

Results

85 eye calls were attended during this period, of which 56 were home-based and 29 were from a hospital setting. Samples from 12 of the former group of donors were found to be positive for COVID-19 (14%).

Conclusion

This study highlights the possibility of postmortem RT-PCR positivity in voluntary corneal tissue donors without a prior history of symptoms, signs, or diagnosis of illness suggestive of COVID-19. It is recommended that postmortem testing of donors should be done by RT-PCR for retrievals made during the pandemic.

Antiviral Properties of Polyphenols from Plants

Polyphenols are active substances against various types of viral infections. Researchers have characterized methods of how to isolate polyphenols without losing their potential to formulate pharmaceutical products. Researchers have also described mechanisms against common viral infections (i.e., influenza, herpes, hepatitis, rotavirus, coronavirus). Particular compounds have been discussed together with the plants in the biomass in which they occur. Quercetin, gallic acid and epigallocatechin are exemplary compounds that inhibit the growth cycle of viruses. Special attention has been paid to identify plants and polyphenols that can be efficient against coronavirus infections. It has been proven that polyphenols present in the diet and in pharmaceuticals protect us from viral infections and, in case of infection, support the healing process by various mechanisms, i.e., they block the entry into the host cells, inhibit the multiplication of the virus, seal blood vessels and protect against superinfection.

Ocular manifestations of RT-PCR-confirmed COVID-19 cases in a large database cross-sectional study

OBJECTIVE

To evaluate ocular manifestations of reverse transcriptase (RT)-PCR-confirmed SARS-CoV-2-infected patients in a validated comparative model, and additionally to evaluate the correlation between severity of COVID-19 and ocular manifestations.

METHODS AND ANALYSIS

In a prospective cross-sectional study, a total of 2400 subjects were enrolled over a period of 8 months. To eliminate bias of identical ocular symptom profile in other non-COVID-19 respiratory infections and to acquire a comparative model, 1200 COVID-19 RT-PCR-positive patients (group 1) and 1200 RT-PCR-negative patients (group 2) were included. Data collection included use of a prestructured tool and 'Google-forms', along with stratification of patients into 'mild, moderate, and severe' categories. Study subjects were evaluated for ocular manifestations by clinical examination and laboratory work-up. Univariate and multivariate logistic regression analyses were performed.

RESULTS

144 (12%) patients in group 1 had ocular symptoms as compared with 24 (2%) patients in group 2 (p<0.001). Ocular manifestations (symptoms and signs) comprising burning sensation (6.7%, p<0.001), foreign body sensation and irritation (7.0%, p<0.001), and conjunctival signs (2.7%, p<0.001) were found statistically significant in group 1 as compared with group 2. Ocular involvement increased in proportion to severity of COVID-19: mild (5.3%), moderate (24.6%) and severe (58.8%) (p=0.0006).

CONCLUSION

The frequency of occurrence of ocular manifestations was higher in group 1 as opposed to group 2. Furthermore, the presence of ocular manifestations carried a direct correlation with severity of systemic disease and presence of comorbidities.

Conjunctivitis as the only sign and symptom of COVID-19: A case report and review of literature

Similar to several viruses, coronaviruses can affect the eye and cause conjunctivitis. In addition to ocular involvement, it causes systemic manifestations, mainly respiratory symptoms. However, conjunctivitis as the only sign and symptom of coronavirus disease 2019 (COVID-19) is a rare presentation. We present a case of a 20-year-old male patient who presented with conjunctivitis for 3 days and diagnosed on the same day with COVID-19 without other manifestations. Conjunctivitis affected both eyes and resolved over 2 weeks with artificial tears only and without any ocular complications.

Conjunctivitis can be the only sign and symptom of COVID-19 in some patients. Therefore, healthcare providers, particularly ophthalmologists, should take precautions when dealing with patients presenting with conjunctivitis amid the COVID-19 pandemic.

Severe COVID-19 and Retina: Are There Any Retinal Manifestations?

PURPOSE

To investigate whether there are retinal lesions associated with severe COVID-19.

METHODS

We studied 232 symptomatic subjects aged 18 - 65 years who had severe COVID-19 and had received treatment. The evaluations included ophthalmological examinations, optical coherence tomography (OCT), imaging modalities with near infrared reflectance (NIR), fundus autofluorescence (FAF), and fundus photography (FP).

RESULTS

The mean age of the patients was 49 years, and 67.6% of them were men. There were no findings of microhemorrhage, cotton wool spots (CWS), vitritis, or retinitis in the examination and imaging.

CONCLUSIONS

This study indicates that retinal involvement as a complication associated with COVID-19 is questionable, although some reports have demonstrated a relationship that may occur secondary to existing systemic diseases.

SARS-CoV-2 and the Eye: The Pandora's Box of Ocular Immunology

The Pandora's box myth addresses the evilness in the world that undisputedly nowadays is identified in severe acute respiratory syndrome (SARS)-Coronavirus 2 (CoV-2), formerly known as Covid-19, which belongs to coronaviridae family, identified in Wuhan, Hubei district of the Republic of China in December 2019. Since then, SARS-CoV-2 has affected ∼180 million people and made almost 4 million victims, with a mortality rate of 6.1%, which is 6 times higher than influenza virus. However, coronaviruses are well known in the ophthalmology field because they were used in the so-called experimental coronavirus retinopathy model. That model certainly brings intriguing concepts for understanding coronavirus pathophysiology, which may have important implications on treatment strategies. Certainly, the recent availability of vaccines gives hope on the control of virus spreading; however, vaccines might create immune reactions involving the eye structure. In this study, we reviewed the literature and elaborated the available data to speculate on possible new interpretation of both pathophysiology and treatment of SARS-CoV-2.

SARS-CoV-2 and the Eyes: A Review of the Literature on Transmission, Detection, and Ocular Manifestations

During the coronavirus disease 2019 (COVID-19) pandemic, numerous reports of ocular anomalies occurring in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged. The most frequently reported pathology is conjunctivitis, which may be the first or only clinical manifestation of the disease. Involvement of SARS-CoV-2 in development of alterations in other ocular structures was suggested, including the cornea, the retina, and blood vessels. Possible mechanisms include direct activity of the viral agent, as well as systemic inflammatory response with accompanying thromboembolic complications. Genetic material of SARS-CoV-2 was detected in ocular secretions of infected individuals, including asymptomatic patients. Moreover, angiotensin-converting enzyme 2 (ACE2), a receptor protein used by the virus to enter the cell, has been found on the surface of various structures of the eye, which indicates a risk of transmission through ocular tissues. Therefore, it is crucial to use eye protection by medical professionals having contact with potentially infected patients. This paper is a review of the literature regarding ocular manifestations of SARS-CoV-2 infection and a summary of the current state of knowledge about possibility of transmission from an ophthalmology point of view. For data collection, a thorough PubMed search was performed, using the key words: "COVID ocular", "COVID eye", "SARS-CoV-2 ocular", and "SARS-CoV-2 eye". Conclusions: SARS-CoV-2 infection may manifest itself in various ocular conditions. Eye protection should not be neglected, as recent studies suggest the eye as a potential route of transmission. Further search for adequate safety measures in ophthalmology practice is required.

Retrospective Analysis of Retinal Imaging in COVID-19 Positive Patients at a Tertiary Eye Care Center

PURPOSE

Since the start of the COVID-19 pandemic, numerous authors have published data demonstrating retinal changes found in patients with COVID-19. However, others have debated the significance of these findings and the effects of COVID-19 on the retina remain uncertain. This study aims to better understand retinal findings in patients with COVID-19.

PATIENTS AND METHODS

A retrospective review of patients with a history of a positive COVID-19 polymerase chain reaction test was performed between March 1st, 2020 and October 31st, 2020. Patients were included if they presented within 90 days of their first positive COVID-19 test and underwent color fundus photography and/or OCT of the macula. All images were reviewed by two independent graders who assessed the presence of retinal heme, cotton wool spots, vascular sheathing, and disc edema, as well as hyper-reflective changes, intra-retinal fluid, and sub-retinal fluid on OCT.

RESULTS

A total of 119 eyes from 61 patients were included. Among 83 eyes which underwent OCT of the macula, inner retinal hyper-reflective changes were seen in 16.9% (n=14), outer retinal hyper-reflective changes in 18.1% (n=15), intra-retinal fluid in 28.9% (n=24), and sub-retinal fluid in 14.5% (n=12). Among 48 eyes which underwent color fundus photography, retinal hemorrhage was seen in 27.1% (n=13), optic disc edema in 2.1% (n=1), and cotton wool spots in none of the eyes. Sub-analysis of 70 eyes from 41 patients with no alternative retinal pathology to potentially explain the above findings revealed none of the above exam findings on OCT of the macula (n=35), fundus photography (n=28), or documented exam (n=66).

CONCLUSION

While a number of patients seen after COVID-19 infection demonstrated retinal findings, all could be explained by pre-existing retinal conditions. In a sub-group of eyes without pre-existing retinal disease, we did not identify any retinal findings that could be associated with COVID-19.

Evaluating the presence of SARS-CoV-2 in the intraocular fluid of COVID-19 patients

PURPOSE

To detect the presence of SARS-CoV-2 in aqueous and vitreous humor of COVID-19 patients in a pilot study.

METHODS

: Consecutive patients planned for emergency ophthalmic surgeries after ocular trauma were subjected to naso-oropharyngeal RT-PCR test for SARS-CoV-2. Laboratory-confirmed cases were enrolled for the study. During surgery, 0.1 mL aqueous and vitreous each was aspirated. The vitreous tap was collected on clinical suspicion of endophthalmitis. RT-PCR test was used to detect SARS-COV-2 nucleotide in the samples. Cycle threshold (Ct) for E gene of ≤35 along with confirmatory results on one of the two target genes (RdRp or ORF1b) was considered as positive.

RESULTS

: One hundred and thirty two patients were found positive on naso-oropharyngeal RT-PCR test for SARS-CoV-2 preoperatively. Seven patients with ocular trauma were studied. The mean age was 31.8 years. There were six male and one female patient. Two patients had symptoms of mild COVID-19 disease and the rest were asymptomatic. The mean Ct value of the E gene on naso-oropharyngeal RT-PCR was 23.14 ± 4.7. Corneal and corneoscleral laceration repair was done in five patients, intracorneal wooden foreign body was removed in one patient, and injection of intravitreal antibiotics was done in one patient. Aqueous and vitreous tap was collected in 7 and 5 patients, respectively. None of the aqueous or vitreous samples was found positive for SARS-CoV-2.

CONCLUSION

: SARS-CoV-2 was not detected by RT-PCR in aqueous or vitreous humor in this pilot study. Future studies with a larger sample size are needed to further explore the presence of SARS-CoV-2 in intraocular fluids.

One Year on: An Overview of Singapore's Response to COVID-19-What We Did, How We Fared, How We Can Move Forward

Background-One year has passed since the first COVID-19 case in Singapore. This scoping review commemorates Singaporean researchers that have expanded the knowledge on this novel virus. We aim to provide an overview of healthcare-related articles published in peer-reviewed journals, authored by the Singapore research community about COVID-19 during the first year of the pandemic. Methods-This was reported using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) protocol. It included healthcare-related articles about COVID-19 published between 23 January 2020 and 22 January 2021 with a Singapore-affiliated author. MEDLINE, Embase, Scopus, Web of Science, CINAHL, PsycINFO, Google Scholar, and local journals were searched. The articles were screened independently by two reviewers. Results-The review included 504 articles. Most of the articles narrated the changes to hospital practice (210), while articles on COVID-19 pathology (94) formed most of the non-narrative papers. Publications on public health (61) and the indirect impacts to clinical outcomes (45) were other major themes explored by the research community. The remaining articles detailed the psychological impact of the pandemic (35), adaptations of medical education (30), and narratives of events (14). Conclusion-Amidst a resurgence of community cases involving variant COVID-19 strains, the resources from the research community will provide valuable guidance to navigate these uncertain times.

COVID-19 and the Use of Immunomodulatory Agents in Ophthalmology

Immunomodulatory agents are often used in the systemic treatment of non-infectious uveitis. These drugs consist of corticosteroids, conventional immunosuppressives, and biological agents. As it is known that they suppress the immune system, the most important concern associated with immunomodulatory therapy (IMT) is the increased risk of infection. The World Health Organization declared COVID-19 a pandemic on 11 March 2020. Although severe acute respiratory distress syndrome secondary to SARS-CoV-2 infection may develop in all people, patients who receive IMT may be at higher risk in terms of both the transmission of the infection and more severe disease course. Therefore, guidelines on the management of patients receiving IMT due to uveitis during the pandemic are needed. In this review, we examined the immunomodulatory drugs used in the treatment of uveitis in terms of infectious complications and the data of patients who received IMT during the COVID-19 pandemic and discussed recommendations for the use of these drugs. According to the latest information, patients who receive IMT may continue their treatment as long as there are no disruptions in regular complete blood count (especially white blood cell count >4,000/μL) and liver and kidney function tests. Patients diagnosed with COVID-19 should be managed with a multidisciplinary approach.

Biomedical Applications of Antiviral Nanohybrid Materials Relating to the COVID-19 Pandemic and Other Viral Crises

The COVID-19 pandemic has driven a global research to uncover novel, effective therapeutical and diagnosis approaches. In addition, control of spread of infection has been targeted through development of preventive tools and measures. In this regard, nanomaterials, particularly, those combining two or even several constituting materials possessing dissimilar physicochemical (or even biological) properties, i.e., nanohybrid materials play a significant role. Nanoparticulate nanohybrids have gained a widespread reputation for prevention of viral crises, thanks to their promising antimicrobial properties as well as their potential to act as a carrier for vaccines. On the other hand, they can perform well as a photo-driven killer for viruses when they release reactive oxygen species (ROS) or photothermally damage the virus membrane. The nanofibers can also play a crucial protective role when integrated into face masks and personal protective equipment, particularly as hybridized with antiviral nanoparticles. In this draft, we review the antiviral nanohybrids that could potentially be applied to control, diagnose, and treat the consequences of COVID-19 pandemic. Considering the short age of this health problem, trivially the relevant technologies are not that many and are handful. Therefore, still progressing, older technologies with antiviral potential are also included and discussed. To conclude, nanohybrid nanomaterials with their high engineering potential and ability to inactivate pathogens including viruses will contribute decisively to the future of nanomedicine tackling the current and future pandemics.

[COVID-19: is transmission through eye contact possible?]

The article reviews international and Russian scientific papers concerning the possibility of transmitting coronavirus infections, particularly the COVID-19, through eye surface. According to the studied literature, the incidence of ocular symptoms in COVID-19 is around 0.8-31.6%, with conjunctivitis being the most frequent manifestation. The review summarizes data on virus detection in conjunctival discharge of COVID-19 patients. Across six studies, the total number of patients is 252, among which were 8 cases (3.17%) of virus detection in the conjunctival cavity. The review discusses the reasons for infrequent detection of the virus in the lacrimal fluid. The analyzed data shows that COVID-19 associated conjunctivitis can be the first symptom, the primary manifestation, or sometimes be detected in the lacrimal fluid of patients without any concomitant signs of eye surface inflammation. The article also presents two clinical cases of patients with keratoconjunctivitis and conjunctivitis associated with COVID-19, as well as the results of experimental transconjunctival and respiratory exposure of Rhesus macaques to SARS-CoV-2 with conclusion of possibility of this type of transmission. Additionally, the review contains the opinion of researchers concerning the influence of several factors on the possibility of virus detection in the lacrimal fluid. The conclusion was made that there is possibility of COVID-19 transmission through the eye surface. While it is not being considered a major transmission route, it should not be ignored. Conjunctival cavity of COVID-19 patients can be the source of infection. Eye protection measures should be undertaken when working with potentially infected patients.

Ocular Adverse Events After COVID-19 Vaccination

PURPOSE

The COVID-19 pandemic has galvanized the development of new vaccines at an unprecedented pace. Since the widespread implementation of vaccination campaigns, reports of ocular adverse effects after COVID-19 vaccinations have emerged. This review summarizes ocular adverse effects possibly associated with COVID-19 vaccination, and discusses their clinical characteristics and management.

METHODS

Narrative Literature Review.

RESULTS

Ocular adverse effects of COVID-19 vaccinations include facial nerve palsy, abducens nerve palsy, acute macular neuroretinopathy, central serous retinopathy, thrombosis, uveitis, multiple evanescent white dot syndrome, Vogt-Koyanagi-Harada disease reactivation, and new-onset Graves' Disease. Studies in current literature are primarily retrospective case series or isolated case reports - these are inherently weak in establishing association or causality. Nevertheless, the described presentations resemble the reported ocular manifestations of the COVID-19 disease itself. Hence, we hypothesize that the human body's immune response to COVID-19 vaccinations may be involved in the pathogenesis of the ocular adverse effects post-COVID-19 vaccination.

CONCLUSION

Ophthalmologists and generalists should be aware of the possible, albeit rare, ocular adverse effects after COVID-19 vaccination.

COVID-19 Ocular Prophylaxis: The Potential Role of Ozonated-Oils in Liposome Eyedrop Gel

Purpose

To assess whether ozonated-oil in liposome eyedrop gel (OED) could be used to prevent the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection in an in vitro infection model.

Methods

First, we tested the efficacy of OED on in vitro cell regeneration and dry eye resolution in human corneal epithelial cells (hCE-2). Second, we assessed the in vitro anti-SARS-CoV-2 infection efficacy of OED using Vero E6 cells. Tissues were examined to assess different parameters: morphology, histology, and mRNA expression at 24 hours after treatment.

Results

OED could restore 50% of the scratch in the monolayer of hCE-2 cells in vitro compared with the 25% obtained with phosphate-buffered saline solution (PBS). At 24 hours after treatment with OED, the number of microvilli and the mucin network were restored, as observed using scanning electron microscopy. In Vero E6 cells infected with a primary SARS-CoV-2 strain and treated with OED two times/day, viral replication was found to be inhibited, with a 70-fold reduction observed at 72 hours after infection compared with that under the untreated and PBS-treated conditions.

Conclusions

SARS-CoV-2 transmission through the ocular surface should not be ignored. Although the prevalence of coronavirus disease 2019 conjunctivitis infection is low, the need for a barrier to prevent possible viral infection is warranted. OED treatment may prevent the risk of SARS-CoV-2 infection after 72 hours of twice-daily applications.

Translational Relevance

Dry eye condition might be a risk factor for SARS-CoV-2 infection and OED treatment may have a preventive role.

Retinal manifestations in patients with SARS-CoV-2 infection and pathogenetic implications: a systematic review

Introduction

The pandemic of COVID-19 has been caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Apart from respiratory malfunction, COVID-19 causes a system-wide thromboembolic state, leading to serious cardiovascular, cerebrovascular and peripheral vascular manifestations. However, our knowledge regarding retinal manifestations due to systemic COVID-19 is minimal. This systematic review has comprehensively summarized all retinal manifestations secondary to COVID-19 disease recorded till date since the beginning of the pandemic.

Methods

All studies published till November 27, 2020, which have reported retinal manifestations in COVID-19 patients were systematically reviewed using the PRISMA statement.

Results

We included 15 articles: 11 case reports and four cross-sectional case series. The most commonly reported manifestations which did not affect visual acuity were retinal hemorrhages and cotton wool spots. The most common vision threatening manifestation was retinal vein occlusion with associated macular edema. Rarely, patients may also present with retinal arterial occlusions and ocular inflammation. These manifestations may occur from as soon as within a week after the onset of COVID-19 symptoms to more than 6 weeks after.

Conclusion

Mostly causing milder disease, COVID-19 may however lead to severe life-threatening thromboembolic complications, and systemic antithrombotic therapy has been suggested as a prophylactic and therapeutic management strategy for patients affected with serious systemic disease. However, both sick and apparently healthy patients may suffer from various retinal complications which may lead to loss of vision as well. No consensus regarding management of retinal complications with anticoagulants or anti-inflammatory medications have been proposed; however, they may be tackled on individual basis.

Impact of SARS-CoV-2 on Ocular Surface Pathology and Treatment Practices: a Review

Purpose of Review

The ocular surface is a potential site of ocular involvement by SARS-CoV-2 infection. We performed a review of the literature to understand the pathogenesis of SARS-CoV-2 disease manifestations on the ocular surface as well as to elucidate emerging treatment patterns and practice changes during the COVID-19 pandemic.

Recent Findings

The ocular manifestations of SARS-CoV-2 are likely limited to a mild and transient conjunctivitis. Other manifestations have not been validated in larger cohorts. Ocular surface tissue should be considered potentially infectious due to the presence of host receptors on surface tissues. The availability of donor tissue in lower-middle income countries has been greatly impacted by the pandemic and would benefit from further investigation into transmissibility through donor tissue.

Summary

Transmission of SARS-CoV-2 through the ocular surface has yet to be confirmed. The most common ocular manifestation is a mild conjunctivitis. Ocular surface surgeons face specific challenges in the use of donor tissues and aerosolizing procedures and have adapted practice patterns accordingly.

Nanotherapeutics for treating coronavirus diseases

Viral diseases have recently become a threat to human health and rapidly become a significant cause of mortality with a continually exacerbated unfavorable socio-economic impact. Coronaviruses, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome (MERS-CoV), and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), have threatened human life, with immense accompanying morbidity rates; the COVID-19 (caused by SARS-CoV-2) epidemic has become a severe threat to global public health. In addition, the design process of antiviral medications usually takes years before the treatments can be made readily available. Hence, it is necessary to invest scientifically and financially in a technology platform that can then be quickly repurposed on demand to be adequately positioned for this kind of pandemic situation through lessons learned from the previous pandemics. Nanomaterials/nanoformulations provide such platform technologies, and a proper investigation into their basic science and biological interactions would be of great benefit for potential vaccine and therapeutic development. In this respect, intelligent and advanced nano-based technologies provide specific physico-chemical properties, which can help fix the key issues related to the treatments of viral infections. This review aims to provide an overview of the latest research on the effective use of nanomaterials in the treatment of coronaviruses. Also raised are the problems, perspectives of antiviral nanoformulations, and the possibility of using nanomaterials effectively against current pandemic situations.

Control of COVID-19 dynamics through a fractional-order model☆

We investigate, through a fractional mathematical model, the effects of physical distance on the SARS-CoV-2 virus transmission. Two controls are considered in our model for eradication of the spread of COVID-19: media education, through campaigns explaining the importance of social distancing, use of face masks, etc., towards all population, while the second one is quarantine social isolation of the exposed individuals. A general fractional order optimal control problem, and associated optimality conditions of Pontryagin type, are discussed, with the goal to minimize the number of susceptible and infected while maximizing the number of recovered. The extremals are then numerically obtained.

COVID 19 repercussions in ophthalmology: a narrative review

BACKGROUND

The new coronavirus of 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally and has repercussions within ophthalmological care. It has caused ocular manifestations in some patients, which can spread through eye secretions.

OBJECTIVES

The purpose of this review was to summarize the currently available evidence on COVID-19 with regard to its implications for ophthalmology.

DESIGN AND SETTING

Narrative review developed by a research group at Universidade Federal de São Paulo (UNIFESP), São Paulo (SP), Brazil, and at Ludwig-Maximilians-Universität, Munich, Germany.

METHODS

We searched the literature on the repercussions of COVID-19 within ophthalmological care, using the MEDLINE and LILACS databases, with the keywords "COVID-19", "ophthalmology" and "coronavirus", from January 1, 2020, to March 27, 2021. Clinical trials, meta-analysis, randomized controlled trials, reviews and systematic reviews were identified.

RESULTS

We retrieved 884 references, of which 42 were considered eligible for intensive review and critical analysis. Most of the studies selected reported the evidence regarding COVID-19 and its implications for ophthalmology.

CONCLUSIONS

Knowledge of eye symptoms and ocular transmission of the virus remains incomplete. New clinical trials with larger numbers of patients may answer these questions in the future. Moreover, positively, implementation of innovative changes in medicine such as telemedicine and artificial intelligence may assist in diagnosing eye diseases and in training and education for students.

Late Corneal Stromal Deposits After COVID-19

ABSTRACT

We present 2 cases of striking stromal corneal infiltrates months after COVID-19 infection. While we cannot prove that these infiltrates are caused by or directly related to COVID-19, we did not find any other plausible cause that could explain these ophthalmic signs. In these cases, the ongoing process was detected in relatively early stages due to scheduled visits with patients and responded positively to prednisolone acetate 1% ophthalmic suspension. However, we do not know the response to treatment in more advanced cases.

Phlyctenular Keratoconjunctivitis in a Patient With COVID-19 Infection

ABSTRACT

The coronavirus disease 2019 global pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several ophthalmic manifestations have been reported to be associated with SARS-CoV-2 infection, including conjunctivitis, acute sixth nerve palsy, and multiple cranial neuropathies. We present a unique case of unilateral phlyctenular keratoconjunctivitis in a 5-year-old boy in the setting of SARS-CoV-2 infection.

COVID-19: more than a respiratory virus, an optical coherence tomography study

Purpose

The purpose of this study is to investigate anatomic and morphologic features of inner and outer retinal layers in patients recovered from COVID-19 with Spectral Domain Optical Coherence Tomography (SD-OCT), whether correlate with any symptoms during disease process.

Methods

32 patients recovered from COVID-19 and age- and gender-matched 36 healthy controls were included in this cross-sectional study. Ganglion cell-inner plexiform layer, macular and peripapiller retinal nerve fiber layer (RNFL), inner nuclear layer (INL), outer nuclear layer (ONL), outer plexiform layer (OPL) and the outer retinal hyperreflective bands including external limiting membrane (ELM), ellipsoid zone (EZ) and interdigitation zone (IZ) were examined with SD-OCT. The differences of each retinal layers thickness among subgroup analysis of ocular pain and headache were also compared.

Results

Macular RNFL of inner and outer nasal and outer inferior quadrants were thinner in COVID-19 patients compared to healthy control group (p = 0.046, p = 0.014 and p = 0.016, respectively). Thinning in outer superior quadrant of GCIPL and INL quadrants were detected in patients with headache (p = 0.026 and p = 0.01). Superonasal and inferotemporal sectors of pRNFL were thinner in patients with ocular pain compared to patients without ocular pain (p = 0.024 and p = 0.015). Integrity of EZ, ELM and IZ was evaluated as continuous line and protected on each OCT scans.

Conclusion

The study demonstrated convincing evidence that SARS-CoV-2 can affect the inner and outer retinal layers, with subclinical localized alterations, particularly in patients with headache and ocular pain symptoms during COVID-19 period.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10792-021-01952-5.

Inhibitory Effect of Ophthalmic Solutions against SARS-CoV-2: A Preventive Action to Block the Viral Transmission?

In 2020, a global pandemic was declared following the spread of SARS-CoV-2, the pathogen responsible for COVID-19. The risk of infection is high due to the ease of transmission, which can occur orally, through droplets, or via contact with contaminated surfaces and objects. It has also been demonstrated that the ocular surface can constitute a transmission route, especially in hospital settings, where health care workers can become a dangerous source of infection. In order to increase prevention and reduce the spread of the virus on the ocular surface, the antiviral activity of already-marketed eye drops against SARS-CoV-2 was evaluated. Iodim, Ozodrop, Septavis, and Dropsept were tested against SARS-CoV-2 in plaque-assay experiments at different stimulation times. Furthermore, the expression levels of early and late genes were evaluated through molecular assays. Results indicated that three of the four ophthalmic solutions showed a considerable dose-dependent inhibition of viral replication, highlighting their use as potential antiviral drugs against SARS-CoV-2 and preventing other ocular infections.

Anterior uveitis onset after bnt162b2 vaccination: is this just a coincidence?

BACKGROUND

Uveitis is a vision-threatening inflammation and is considered an ophthalmic emergency. It generally arises as a result of autoimmune conditions, infections, or ocular trauma, but it may also occur as an isolated disorder. Over the past decades, several cases of vaccine-associated uveitis have been described, with the hepatitis B virus vaccine being the leading cause.

CLINICAL CASE

A case of anterior uveitis in a 23-year-old male, with onset 14 days after the second dose of BNT162b2 COVID-19 vaccine, is reported here. Initial symptoms were pain, photophobia, and red eye. Ocular examination showed pericheratic and conjunctival hyperaemia, posterior synechiae, and anterior chamber cells ± keratic precipitates in the lower quadrants. The posterior segment did not show any alteration, and optical coherence tomography ruled out the presence of cystoid macular oedema. After a 10-day treatment course of topical steroids and cycloplegic eye drops, the ocular inflammatory signs disappeared and visual acuity was completely restored. Even if causality remains presumed, a warning should be given to physicians about the possibility of eye inflammation following SARS-CoV-2 vaccination.

Mechanistic Aspects of Medicinal Plants and Secondary Metabolites against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

BACKGROUND AND OBJECTIVE

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a highly pathogenic virus, is responsible for a respiratory disease termed coronavirus disease 2019 (COVID-19). SARS-CoV-2 genome encodes various structural and non-structural proteins, which are necessary for viral entry and replication. Among these proteins, papain-like protease (PLpro), 3C-like protease (3CLpro), RNA-dependent RNA polymerase (RdRp), helicase, a serine protease, and spike protein are potential targets of herbal remedies and phytocompounds for inhibition of viral infection and replication. There is at present no confirmed cure for the COVID-19. Various plants and their components have been introduced against SARS-Co-2. A number of review articles have also been published on them. This article is focusing on the mechanistic aspects of these plants and their derivatives on SARS-CV-2.

METHOD

The material in this review article was prepared from significant scientific databases, including Web of Science, PubMed, Science Direct, Scopus and Google Scholar.

RESULTS

Different medicinal plants and their phytocompounds interact with important structural and non-structural of SARS-CoV-2 proteins. Natural compounds form strong bonds with the active site of SARS-CoV-2 protease and make large conformational changes. These phytochemicals are potential inhibitors of structural and non-structural of SARS-CoV-2 proteins such as Spike protein, PLpro, and 3CLpro. Some important anti-SARS-CoV-2 actions of medicinal plants and their metabolites are inhibition of the virus replication or entry, blocking the angiotensin-converting enzyme 2 (ACE-2) receptor and "Transmembrane protease, serine 2 (TMPRSS2)" regulation of inflammatory mediators, inhibition of endothelial activation, toll-like receptors (TLRs) and activation of the nuclear factor erythroid-derived 2-related factor 2 (Nrf2). Some of these important natural immune boosters that are helpful for prevention and curing various symptoms related to COVID-19 include Allium sativum, Nigella sativa, Glycyrrhiza glabra Zingiber officinalis, Ocimum sanctum, Withania somnifera, Tinospora cordifolia, and Scutellaria baicalensis. Also, Kaempferol, Quercetin, Baicalin, Scutellarin, Glycyrrhizin, Curcumin, Apigenin, Ursolic acid, and Chloroquine are the best candidates for treating the symptoms associated with SARS-CoV-2 infection.

CONCLUSION

Medicinal plants and/or their bioactive compounds with inhibitory effects against SARS-CoV-2 support the human immune system and help in fighting against COVID-19 and rejuvenating the immune system.

Vitreoretinal abnormalities in corona virus disease 2019 patients: What we know so far

The coronavirus disease 2019 (COVID-19) has become a global pandemic since December 2019. Although COVID-19 primarily affects the respiratory systems, it has become abundantly clear that it involves multiple organs including the heart, kidney, skin, and brain. Neuro-ophthalmic signs and anterior segment inflammation of the eyes were documented in COVID-19 patients recently. Small but growing number of literatures has also reported the cases of new onset vitreoretinal disorders related to COVID-19 infection. A comprehensive search from four online databases was done. Findings show vitreoretinal involvement in COVID-19 patients including the central retinal vein occlusion, central retinal artery occlusion, reactivation of previous uveitis, chorioretinitis, macular hemorrhage, acute macular neuroretinopathy, paracentral acute middle maculopathy, vitritis with outer retinal abnormalities, varicella zoster virus-related acute retinal necrosis in immunocompromised patient, and other posterior segment pathological changes. The hypotheses for potential pathogenesis of these manifestations are direct viral ocular infection and thromboembolic complications secondary to the hyperinflammatory response. This is the first review article, which provides an overview of current evidence regarding the vitreoretinal manifestations in COVID-19 patients.

Identification of phytochemical inhibitors against main protease of COVID-19 using molecular modeling approaches

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel corona virus that causes corona virus disease 2019 (COVID-19). The COVID-19 rapidly spread across the nations with high mortality rate even as very little is known to contain the virus at present. In the current study, we report novel natural metabolites namely, ursolic acid, carvacrol and oleanolic acid as the potential inhibitors against main protease (Mpro) of COVID-19 by using integrated molecular modeling approaches. From a combination of molecular docking and molecular dynamic (MD) simulations, we found three ligands bound to protease during 50 ns of MD simulations. Furthermore, the molecular mechanic/generalized/Born/Poisson-Boltzmann surface area (MM/G/P/BSA) free energy calculations showed that these chemical molecules have stable and favourable energies causing strong binding with binding site of Mpro protein. All these three molecules, namely, ursolic acid, carvacrol and oleanolic acid, have passed the ADME (Absorption, Distribution, Metabolism, and Excretion) property as well as Lipinski's rule of five. The study provides a basic foundation and suggests that the three phytochemicals, viz. ursolic acid, carvacrol and oleanolic acid could serve as potential inhibitors in regulating the Mpro protein's function and controlling viral replication. Communicated by Ramaswamy H. Sarma.

Eye care professionals' patient care and personal protective equipment adapts during the second wave of SARS-CoV-2: Survey in Israel

The coronavirus disease (COVID-19) began spreading in December 2019 and rapidly evolved to a global pandemic. Initially information was nonexistent and eye care professionals (ECPs) were anxious as the close proximity involved in patient care put them at high risk. Recognizing this stress and the probable effect on behavior initiated this survey. The survey presented here was conducted in three stages. The expectation was a change in behavior during the second wave when modes of transmission and methods of protection clarified. Yet nearly a third of ECPs still refrained from examining patients. This continuing trend can have severe health and economic ramifications.

Retinal Involvement in COVID-19: Results From a Prospective Retina Screening Program in the Acute and Convalescent Phase

Objective: To detect retinal involvement in coronavirus disease 2019 (COVID-19) patients in acute and convalescent phase by their fundus screening.

Methods: In a prospective, cross-sectional, observational study (July–November 2020), 235 patients (142 acute and 93 convalescent phase) underwent fundus screening in a tertiary care center in North India. For convalescent phase, “hospitalized” patients (73) were screened at least 2 weeks after hospital discharge, and “home-isolated” patients (20) were screened 17 days after symptom onset/COVID-19 testing.

Results: None in acute phase showed any retinal lesion that could be attributed exclusively to COVID-19. Five patients (5.38%) in convalescent phase had cotton wool spots (CWSs) with/without retinal hemorrhage, with no other retinal finding, and no visual symptoms, seen at a median of 30 days from COVID-19 diagnosis.

Conclusions: CWSs (and retinal hemorrhages) were an incidental finding in COVID-19, detected only in the convalescent phase. These patients were much older (median age = 69 years) than the average age of our sample and had systemic comorbidities (diabetes mellitus, hypertension, etc.). We propose the term “COVID-19 retinopathy” to denote the presence of CWSs at the posterior pole, occasionally associated with intraretinal hemorrhages, in the absence of ocular inflammation in patients with a history of COVID-19 disease.

Human tear fluid analysis for clinical applications: progress and prospects

Introduction: Human blood and saliva are increasingly under investigation for the detection of biomarkers for early diagnosis of non-communicable (e.g.cancers) and communicable diseases like COVID-19. Exploring the potential application of human tears, an easily accessible body fluid, for the diagnosis of various diseases is the need of the hour.Areas covered: This review deals with a comprehensive account of applications of tear analysis using different techniques, their comparison and overall progress achieved till now. The techniques used for tear fluid analysis are HPLC/UPLC/SDS-PAGE, CE, etc., together with ELISA, Mass Spectrometry, etc. But, with advances in instrumentation and data processing methods, it has become easy to couple the various separation methods with highly sensitive optical techniques for the analysis of body fluids.Expert opinion: Tear analysis can provide valuable information about the health condition of the eyes since it contains several molecular constituents, and their relative concentrations may alter under abnormal conditions. Tear analysis has the advantage that it is totally non-invasive. This study recommends tear fluid as a reliable clinical sample to be probed by highly sensitive optical techniques to diagnose different health conditions, with special emphasis on eye diseases.

[Providing eye care during the COVID-19 pandemic]

The review presents the data on characteristic features of the new coronavirus infection caused by SARS-CoV-2 and the possibility of its transmission through the eye surface and lacrimal fluid, analyzes the information on eye damage caused by COVID-19, and provides the results of a systematic meta-analysis on the subject. The author describes the system for organizing ophthalmological care in the settings of unfavorable epidemiological situation associated with the COVID-19 pandemic, and considers the preventive measures of infection transmission between patients and medical personnel. The article also gives recommendations for sterilizing medical equipment.