|
|
ORIGINAL ARTICLE |
|
Year : 2020 | Volume
: 68
| Issue : 6 | Page : 1015-1017 |
|
Presence of viral RNA of SARS-CoV-2 in conjunctival swab specimens of COVID-19 patients
Kiran Kumar1, Akshata A Prakash1, Suresh Babu Gangasagara1, Sujatha B L Rathod1, K Ravi2, Ambica Rangaiah3, Sathyanarayan Muthur Shankar3, Shantala Gowdara Basawarajappa3, Shashi Bhushan4, TG Neeraja1, Srinivas Khandenahalli1, M Swetha1, Priyam Gupta1, UC Sampritha1, Guru N S Prasad1, Chakravarthy Raghunathan Jayanthi5
1 Department of Ophthalmology, Minto Ophthalmic Hospital, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India 2 Department of Medicine, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India 3 Department of Microbiology, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India 4 Department of Pulmonary Medicine, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India 5 Department of Pharmacology, Bangalore Medical College and Research Institute, Bengaluru, Karnataka, India
Date of Submission | 05-May-2020 |
Date of Acceptance | 16-May-2020 |
Date of Web Publication | 25-May-2020 |
Correspondence Address: Dr. Kiran Kumar Cataract, Cornea and Refractive Services, Minto Regional Institute of Ophthalmology, Bangalore Medical College and Research Institute, Bengaluru - 560 002, Karnataka India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/ijo.IJO_1287_20
Purpose: To detect the presence of viral RNA of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in conjunctival swab specimens of coronavirus disease-19 (COVID-19) patients. Methods: Forty-five COVID-19 patients positive for real-time reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 in nasopharyngeal swab with or without ocular manifestations were included in the study. The conjunctival swab of each patient was collected by an ophthalmologist posted for COVID duty. Results: Out of 45 patients, 35 (77.77%) were males and the rest were females. The mean age was 31.26 ± 12.81 years. None of the patients had any ocular manifestations. One (2.23%) out of 45 patients was positive for RT-PCR SARS-CoV-2 in the conjunctival swab. Conclusion: This study shows that SARS-CoV-2 can be detected in conjunctival swabs of confirmed cases of COVID-19 patients. Though the positivity rate of detecting SARS-CoV-2 in conjunctival swabs is very less, care should be exercised during the ocular examination of patients of COVID-19.
Keywords: Conjunctival swab, coronavirus disease-19, nasopharyngeal swab, SARS-CoV-2
How to cite this article: Kumar K, Prakash AA, Gangasagara SB, Rathod SB, Ravi K, Rangaiah A, Shankar SM, Basawarajappa SG, Bhushan S, Neeraja T G, Khandenahalli S, Swetha M, Gupta P, Sampritha U C, Prasad GN, Jayanthi CR. Presence of viral RNA of SARS-CoV-2 in conjunctival swab specimens of COVID-19 patients. Indian J Ophthalmol 2020;68:1015-7 |
How to cite this URL: Kumar K, Prakash AA, Gangasagara SB, Rathod SB, Ravi K, Rangaiah A, Shankar SM, Basawarajappa SG, Bhushan S, Neeraja T G, Khandenahalli S, Swetha M, Gupta P, Sampritha U C, Prasad GN, Jayanthi CR. Presence of viral RNA of SARS-CoV-2 in conjunctival swab specimens of COVID-19 patients. Indian J Ophthalmol [serial online] 2020 [cited 2023 Feb 1];68:1015-7. Available from: https://www.ijo.in/text.asp?2020/68/6/1015/284769 |
Since December 2019, there have been cases of coronavirus disease 2019 (COVID-19) reported in China, which soon spread to other parts of the world. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen which is a member of the Coronaviridae family. A few researchers have reported keratoconjunctivitis as an ocular abnormality of SARS-CoV-2.[1] Signs and symptoms of COVID-19 have been described as fever, cough, myalgia, fatigue, sputum production, headache, hemoptysis, diarrhea, and conjunctivitis.[2] Since the diagnosis of COVID-19 patients cannot be only based on symptoms, reverse transcription-polymerase chain reaction (RT-PCR) is a simple and reliable molecular test on respiratory samples (throat swab/nasopharyngeal swab/sputum/endotracheal aspirates, and bronchoalveolar lavage).[3]
Close examination of patients by ophthalmologists and physical contact with patients' eyes is inevitable. This could be a potential source of the spread of SARS-CoV-2. Other viruses like adenovirus and influenza viruses are known for ocular tropism.[4] Therefore, this study was designed to understand whether SARS-CoV-2 can be detected in the conjunctival swab of patients of COVID-19.
Methods | |  |
A prospective interventional study was conducted at a dedicated tertiary COVID-19 hospital in south India in April 2020. Institute ethical clearance was obtained prior to the onset of the study. Confirmed positive cases of COVID-19 by nasopharyngeal swab according to WHO standards with or without ocular symptoms were included in the study.[5] Suspect and probable cases and those patients who were critically ill were excluded. Signed consent was obtained for each sample collection from patients. The conjunctival swab was collected by an ophthalmologist posted for COVID duty. Eyelids were everted and samples were obtained by sweeping the inferior fornices of either of the two eyes with sterile nylon flocked swabs without topical anesthesia. The tips of the swab sticks were broken off and placed into a viral transport medium—Hi media (HiMedia Laboratories Pvt. Ltd, Nashik, India. Catalog No: 0000431084). Personal protection equipment was used and necessary precautions were used to minimize the risk of spread of infection from one patient to another. Samples were transported to the specified lab facility maintaining the recommended cold chain. In the laboratory, samples were extracted using the magnetic bead extraction method (Thermo scientific viral isolation kit—5X MagMAX, Thermo Fischer scientific Baltics UAB, Vilnius, Lithuania) in Biomek 4000 platform as per the manufacturer's instructions. In eight-strip PCR tubes, 22.5 μL of the mixed reaction solution or master mix (SARS CoV-2 Detection kit; fortitude 2.0) was loaded. To this, 2.5 μL of the extracted nucleic acid was added to each well, covered and the PCR was performed using the CFX96 real-time PCR (Bio-Rad). After the completion of the PCR run, the amplification curves were judged to decide if the results were negative or positive. A cutoff cycle threshold (Ct) value of 40 was considered as positive as per the manufacturer's instructions.
Results | |  |
Out of 45 patients, 35 (77.77%) were males and the rest were females. Patients with a minimum age of 6 years and a maximum age of 75 years were present in the study. For our convenience, patients were divided into four age groups: less than 20 years (6); 21–40 years (29); 41–60 years (9), and more than 60 years (1). The mean age (±SD) was 31.26 ± 12.81 years. None of the patients in our study had any ocular symptoms.
Only one (2.23%) out of 45 patients was positive with the Ct value of 33, for real-time RT-PCR SARS-CoV-2 in conjunctival swab as shown in [Table 1]. | Table 1: Demography, clinical symptoms, nasopharyngeal swab, and conjunctival swab reports of coronavirus disease-19-positive patients
Click here to view |
Discussion | |  |
No reports were suggesting ocular transmission of COVID-19 initially. Xia et al. evaluated the conjunctival secretions of 30 confirmed cases of COVID-19.[6] In one of these patients, both tear and conjunctival secretions tested positive for the virus by RT-PCR. There are numerous anecdotal reports suggesting conjunctivitis as the initial symptom before the onset of pneumonia, including that of Guangfa Wang, a national expert on the panel for pneumonia during the early investigations in Wuhan, China.[7]
Some studies reported the presence of SARS-CoV or Middle-East respiratory syndrome (MERS-CoV) in tears or conjunctival sac.[8] Another study by Chen et al. detected SARS-CoV-2 in the conjunctival sac of only three COVID-19 patients out of 67 positive cases. But these three patients did not have any ocular symptoms.[9] Sun et al. found that among 72 patients confirmed by laboratory diagnosis with SARS-CoV-2 RT-PCR assay, SARS-CoV-2 RNA fragments were found in ocular discharges belonging to one patient.[10] The above studies show that SARS-CoV-2 can be detected in conjunctival sac, in only a small percentage of COVID-19 positive patients. Also, the risk of infection of SARS-CoV-2 through eye secretions remains uncertain.
Our study showed that only one (2.23%) out of 45 patients had detectable levels of SARS-CoV-2 in conjunctival swabs of COVID-19-positive patients using RT-PCR. Low level of viral detection can be due to various factors like the time for maximum replication of the virus, the timing of performing of sampling, time of presentation of the patient to the hospital and possibly less secretion of the virus through conjunctival secretion, and also low sensitivity of RT-PCR.[11] In a study done by Ziad and colleagues, tracheal aspirates yielded a higher SARS-CoV-2 load than a nasopharyngeal swab.[12] This suggests that viral concentration differs in different sites and secretions. A study was done by de Wit et al. in the rhesus macaque model with MERS-CoV, which is another type of coronavirus.[13] They found out that MERS-CoV RNA could be detected in the conjunctiva well within 6 days of infection beyond which, it failed to detect the virus. Since the majority of people infected with the SARS-CoV-2 virus are asymptomatic, it is difficult to determine the peak of virus load unless multiple samplings are done at varied intervals.
There are several limitations to this study which include relatively small sample size, absence of detailed ocular examinations, sampling done only once from the eyes of each patient, which can increase the prevalence of false-negatives.
Conclusion | |  |
This study shows that SARS-CoV-2 can be detected in conjunctival swabs of confirmed cases of COVID-19 patients. Though the positivity rate of detecting SARS-CoV-2 in conjunctival swabs is very less, care should be exercised during the ocular examination of patients of COVID-19.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References | |  |
1. | Lu R, Zhao X, Li J, Niu P, Yang B, Wu H, et al. Genomic characterisation and epidemiology of 2019 novel coronavirus: Implications for virus origins and receptor binding. Lancet 2020;395:565-74. |
2. | Huang C, Wang Y, Li X. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506. |
3. | Shen M, Zhou Y, Ye J, Abdullah AL-maskri AA, Kang Y, Zeng S, et al. Recent advances and perspectives of nucleic acid detection for coronavirus. J Pharm Anal 2020;10:97-101. |
4. | Nilsson EC, Storm RJ, Bauer J, Johansson SM, Lookene A, Šngström J, et al. The GD1a glycan is a cellular receptor for adenoviruses causing epidemic keratoconjunctivitis. Nat Med 2011;17:105-9. |
5. | World Health Organization. Case definitions for surveillance of severe acute respiratory syndrome (SARS). |
6. | Xia J, Tong J, Liu M, Shen Y, Guo D. Evaluation of coronavirus in tears and conjunctival secretions of patients with SARS-CoV-2 infection. J Med Virol 2020. doi: 10.1002/jmv. 25725. [Epub ahead of print]. |
7. | Lu CW, Liu XF, Jia ZF. 2019-nCoV transmission through the ocular surface must not be ignored. Lancet 2020;395(10224):e39. |
8. | Loon SC, Teoh SC, Oon LL, Se-Thoe SY, Ling AE, Leo YS, et al. The severe acute respiratory syndrome coronavirus in tears. Br J Ophthalmol 2004;88:861-3. |
9. | Yunyun Zhou, Yuyang Zeng, Yongqing Tong, ChangZheng Chen. Ophthalmologic evidence against the interpersonal transmission of 2019 novel coronavirus through conjunctiva. med Rxiv 2020. doi: https://doi.org/10.1101/2020.02.11.20021956. (Preprint) |
10. | Zhang X, Chen X, Chen L, Deng C, Zou X, Liu W, et al. The evidence of SARS-CoV-2 infection on ocular surface. Ocul Surf. 2020 Apr 11. pii: S1542-0124(20)30065-3. doi: 10.1016/j.jtos.2020.03.010. [Epub ahead of print]. |
11. | Yang Y, Yang M, Shen C, Wang F, Yuan J, Li J, et al. Laboratory diagnosis and monitoring the viral shedding of 2019-nCoVinfections. medRxiv preprint. doi: 10.1101/2020.02.11.20021493. (Preprint). |
12. | Memish ZA, Al-Tawfiq JA, Makhdoom HQ, Assiri A, Alhakeem RF, Albarrak A, et al. Respiratory tract samples, viral load, and genome fraction yield in patients with Middle East respiratory syndrome. J Infect Dis 2014;210:1590-4. |
13. | de Wit E, Rasmussen AL, Falzarano D, Bushmaker T, Feldmann F, Brining DL, et al. Middle East respiratory syndrome coronavirus (MERS-CoV) causes transient lower respiratory tract infection in rhesus macaques. Proc Natl Acad Sci U S A 2013;110:16598-603. |
[Table 1]
This article has been cited by | 1 |
Conjunctival conveyance of SARS-CoV-2 in asymptomatic and non-severe symptomatic COVID-19 patients |
|
| A. Rousseau, C. Vauloup-Fellous, O. Haigh, S. Pavy, D. Molinari, S. Jauréguiberry, A. Angoulvant, M. Labetoulle | | Journal Français d'Ophtalmologie. 2023; | | [Pubmed] | [DOI] | | 2 |
SARS-COV-2 viral load in tears of patients with COVID-19 in the early symptomatic stages: comparison of two different tear sampling methods |
|
| A. Sonmez, S. Aydin Kurna, F. G. Aslan, F. B. Kaplan, B. Açikalin, P. Eker | | International Ophthalmology. 2022; | | [Pubmed] | [DOI] | | 3 |
Risk of aerosolization and the importance of corneal hysteresis measurements in Glaucoma patients during the COVID-19 Era |
|
| Marko Oydanich, Albert S. Khouri | | International Ophthalmology. 2022; | | [Pubmed] | [DOI] | | 4 |
Analysis of SARS-CoV-2 in Corneal Tissue of Deceased Asymptomatic Novel Coronavirus Disease 2019 Donors |
|
| Karthikeyan Mahalingam, Dewang Angmo, Aanchal Kakkar, Rahul Kumar Bafna, Tushar Sharma, Aishwarya Rai, Sahil Agrawal, Lalit Dar, Rohit Saxena, Jeewan S. Titiyal, Namrata Sharma | | Cornea. 2022; Publish Ah | | [Pubmed] | [DOI] | | 5 |
COVID-19 and the eye: alternative facts The 2022 Bowman Club, David L. Easty lecture |
|
| Lawson Ung, James Chodosh | | BMJ Open Ophthalmology. 2022; 7(1): e001042 | | [Pubmed] | [DOI] | | 6 |
SARS-CoV-2 RNA Detected in Vitreous Samples Obtained at Autopsy |
|
| Marisa Tieger, Upasana Das Adhikari, Shizuo Mukai, Mara Farcasnu, James R. Stone, Dean Eliott, Leo A. Kim, Douglas S. Kwon, Elizabeth J. Rossin | | Journal of VitreoRetinal Diseases. 2022; : 2474126422 | | [Pubmed] | [DOI] | | 7 |
Ocular manifestations of COVID-19 |
|
| Mashael Al-Namaeh | | Therapeutic Advances in Ophthalmology. 2022; 14: 2515841422 | | [Pubmed] | [DOI] | | 8 |
Awareness and knowledge of ocular manifestation in COVID-19 patients among health care workers (HCWs) in Central India |
|
| Kanishk Singh, Puja Bang, Rajesh Pattebahadur, Amrita Singh | | Indian Journal of Clinical and Experimental Ophthalmology. 2022; 8(2): 228 | | [Pubmed] | [DOI] | | 9 |
Conjunctival Swab Findings in 484 COVID-19 Patients in Four Hospital Centers in Slovakia |
|
| Alena Furdova, Pavol Vesely, Michal Trnka, Elena Novakova, Michal Stubna, Robert Furda, Lubica Branikova, Zuzana Pridavkova | | Vision. 2022; 6(3): 46 | | [Pubmed] | [DOI] | | 10 |
Analysis of ophthalmic emergency visits during COVID-19 Lockdown in a tertiary eye care center in South India |
|
| SohamSubodhchandra Pal, MdShahid Alam, SarangMurlidharrao Giratkar, Bipasha Mukherjee | | TNOA Journal of Ophthalmic Science and Research. 2022; 60(1): 2 | | [Pubmed] | [DOI] | | 11 |
Ocular Manifestations in Children with COVID-19: Systematic Review and Meta-Analysis |
|
| Naser Nasiri, Hamid Sharifi, Tahereh Rahimi, Ghodsieh Sharif, Ali Sharifi | | Journal of Medical Microbiology and Infectious Diseases. 2022; 10(2): 58 | | [Pubmed] | [DOI] | | 12 |
Detection of coronavirus-2 by real-time reverse transcription polymerase chain reaction in conjunctival swabs from patients with severe form of Coronavirus disease 2019 in São Paulo, Brazil |
|
| Mariana Akemi Matsura Misawa, Tatiana Tanaka, Tomás Minelli, Pedro Gomes Oliveira Braga, Juliana Mika Kato, Michele Soares Gomes Gouvêa, João Renato Rebello Pinho, Joyce Hisae Yamamoto | | Clinics. 2021; 76 | | [Pubmed] | [DOI] | | 13 |
Bilateral neurorethinovasculitis associated with COVID-19 infection in a girl 17 years old |
|
| Ekaterina Denisova, E. N Demchenko, Elizaveta A. Geraskina, Mariia A. Khrabrova, Anna Y. Panova | | Russian Pediatric Ophthalmology. 2021; 16(2): 41 | | [Pubmed] | [DOI] | | 14 |
Response to comments on: Clinical profile and prevalence of conjunctivitis in mild COVID-19 patients in a tertiary care COVID-19 hospital: A retrospective cross-sectional study |
|
| K Sindhuja, Neiwete Lomi, MohamedI Asif, Radhika Tandon | | Indian Journal of Ophthalmology. 2021; 69(1): 166 | | [Pubmed] | [DOI] | | 15 |
Propensity of aerosol and droplet creation during oculoplastic procedures: A risk assessment with high-speed imaging amidst COVID-19 pandemic |
|
| Roshmi Gupta, Khushboo Pandey, Rwituja Thomas, Saptarshi Basu, Bhujang Shetty, Rohit Shetty, AbhijitSinha Roy | | Indian Journal of Ophthalmology. 2021; 69(3): 734 | | [Pubmed] | [DOI] | | 16 |
Fundus evaluation in COVID-19 positives with non-severe disease |
|
| Ravi Bypareddy, BL Sujatha Rathod, YD Shilpa, HR Hithashree, KalpanaBadami Nagaraj, BC Hemalatha, Jessica Basumatary, Deeksha Bekal, R Niranjan, PG Anusha | | Indian Journal of Ophthalmology. 2021; 69(5): 1271 | | [Pubmed] | [DOI] | | 17 |
Vitreoretinal abnormalities in corona virus disease 2019 patients: What we know so far |
|
| Nathania Sutandi, Felix Lee | | Taiwan Journal of Ophthalmology. 2021; 0(0): 0 | | [Pubmed] | [DOI] | | 18 |
A Year of Living Dangerously: Challenges and Recommendations for Safely Performing Ophthalmic Surgery During the COVID-19 Pandemic, from Start to Finish |
|
| Juan Pablo Salica, Constanza Potilinski, Marcia Querci, Ignacio Navarro, Juan Sebastián Rivero, Pablo Daponte, Roberto Pineda ll, Juan E Gallo | | Clinical Ophthalmology. 2021; Volume 15: 261 | | [Pubmed] | [DOI] | | 19 |
Evidence of SARS-CoV-2 Transmission Through the Ocular Route |
|
| Jing-Yu Qu, Hua-Tao Xie, Ming-Chang Zhang | | Clinical Ophthalmology. 2021; Volume 15: 687 | | [Pubmed] | [DOI] | | 20 |
Testing the Sensitivity of Conjunctival Swabs from Confirmed COVID-19 Patients |
|
| Manal Hadrawi, Mohammad Malak, Faeeqah Almahmoudi, Ahmed Mogharbel, Omar Rozy, Somaya Hanafi, Batool Ali, Sanaa Nabeel, Fatimah Fagieha, khaled Alzahrani | | Clinical Ophthalmology. 2021; Volume 15: 2489 | | [Pubmed] | [DOI] | | 21 |
Wuhan to World: The COVID-19 Pandemic |
|
| Ashok Kumar, Rita Singh, Jaskaran Kaur, Sweta Pandey, Vinita Sharma, Lovnish Thakur, Sangeeta Sati, Shailendra Mani, Shailendra Asthana, Tarun Kumar Sharma, Susmita Chaudhuri, Sankar Bhattacharyya, Niraj Kumar | | Frontiers in Cellular and Infection Microbiology. 2021; 11 | | [Pubmed] | [DOI] | | 22 |
Do Ocular Fluids Represent a Transmission Route of SARS-CoV-2 Infection? |
|
| Giulio Petronio Petronio, Roberto Di Marco, Ciro Costagliola | | Frontiers in Medicine. 2021; 7 | | [Pubmed] | [DOI] | | 23 |
Exposure of Ophthalmologists to Patients' Exhaled Droplets in Clinical Practice: A Numerical Simulation of SARS-CoV-2 Exposure Risk |
|
| Yanchao Fan, Li Liu, Hui Zhang, Yingping Deng, Yi Wang, Mengjie Duan, Huan Wang, Lixiang Wang, Leifeng Han, Yalin Liu | | Frontiers in Public Health. 2021; 9 | | [Pubmed] | [DOI] | | 24 |
Transmission of SARS-CoV-2 Indoor and Outdoor Environments |
|
| Xueli Xu, Jing Zhang, Liting Zhu, Qiansheng Huang | | Atmosphere. 2021; 12(12): 1640 | | [Pubmed] | [DOI] | | 25 |
Investigation of SARS-CoV-2 in tear and conjunctival secretions of hospitalized patients with clinically-confirmed COVID-19 pneumonia |
|
| Yunus Karabela, Semsi Nur Karabela, Mehmet Ozbas, Havva Kasikci, Kadriye Kart Yasar | | BMC Infectious Diseases. 2021; 21(1) | | [Pubmed] | [DOI] | | 26 |
Covid-19 and contact lenses: Keeping it simple in the ‘new normal’ |
|
| Karen Walsh, Lyndon Jones | | Optician. 2021; 2021(3): 8511-1 | | [Pubmed] | [DOI] | | 27 |
Manifestations and Virus Detection in the Ocular Surface of Adult COVID-19 Patients: A Meta-Analysis |
|
| Yu-Yen Chen, Yung-Feng Yen, Li-Ying Huang, Pesus Chou, Yedi Zhou | | Journal of Ophthalmology. 2021; 2021: 1 | | [Pubmed] | [DOI] | | 28 |
Risk Assessment of Aerosol Generation During Vitreoretinal Surgery Using High Speed Imaging Amidst the COVID-19 Pandemic |
|
| Chaitra Jayadev, Thirumalesh Mochi Basavaraj, Khushboo Pandey, Roven Pinto, Shashi Prabha Pandey, Saptarshi Basu, Abhijit Sinha Roy, Rohit Shetty | | Translational Vision Science & Technology. 2021; 10(12): 17 | | [Pubmed] | [DOI] | | 29 |
The impact of COVID-19 related national lockdown on ophthalmic emergency in Italy: A multicenter study |
|
| Maria L Salvetat, Carlo Salati, Patrizia Busatto, Marco Zeppieri | | European Journal of Ophthalmology. 2021; : 1120672121 | | [Pubmed] | [DOI] | | 30 |
Ophthalmology-focused publications and findings on COVID-19: A systematic review |
|
| Ya-Ping Jin, Graham E Trope, Sherif El-Defrawy, Elin Y Liu, Yvonne M Buys | | European Journal of Ophthalmology. 2021; 31(4): 1677 | | [Pubmed] | [DOI] | | 31 |
Glaucoma care during the coronavirus disease 2019 pandemic |
|
| Kateki Vinod, Paul A. Sidoti | | Current Opinion in Ophthalmology. 2021; 32(2): 75 | | [Pubmed] | [DOI] | | 32 |
Comparison of the simultaneous conjunctiva and oropharynx–nasopharynx swab results in patients applying to the SARS-CoV-2 outpatient clinic for the first time |
|
| Ayten Gunduz, Murat Firat, Gamze Turkoglu | | Journal of Medical Virology. 2021; 93(7): 4516 | | [Pubmed] | [DOI] | | 33 |
Prevalence of SARS-CoV-2 amongst ophthalmologists throughout the first and second waves of the pandemic |
|
| Matteo Sacchi, Rosario Alfio Umberto Lizzio, Edoardo Villani, Elena Tagliabue, Gianluca Monsellato, Giorgio Pajardi, Saverio Luccarelli, Paolo Nucci | | Medicine. 2021; 100(50): e28192 | | [Pubmed] | [DOI] | | 34 |
Detection of SARS-CoV-2 in conjunctival secretions from patients without ocular symptoms |
|
| Xin Li, Jasper Fuk-Woo Chan, Kenneth Kai-Wang Li, Eugene Yuk-Keung Tso, Cyril Chik-Yan Yip, Siddharth Sridhar, Tom Wai-Hin Chung, Kelvin Hei-Yeung Chiu, Derek Ling-Lung Hung, Alan Ka-Lun Wu, Sandy Ka-Yee Chau, Raymond Liu, Kwok-Cheung Lung, Anthony Raymond Tam, Vincent Chi-Chung Cheng, Kelvin Kai-Wang To, Kwok-Hung Chan, Ivan Fan-Ngai Hung, Kwok-Yung Yuen | | Infection. 2021; 49(2): 257 | | [Pubmed] | [DOI] | | 35 |
Evaluation of SARS-CoV-2 in Tears of Patients with Moderate to Severe COVID-19 |
|
| Ritu Arora, Ruchi Goel, Sumit Kumar, Mohit Chhabra, Sonal Saxena, Vikas Manchanda, Palak Pumma | | Ophthalmology. 2021; 128(4): 494 | | [Pubmed] | [DOI] | | 36 |
Ocular manifestations in COVID-19 patients: A systematic review and meta-analysis |
|
| Yueyang Zhong, Kai Wang, Yanan Zhu, Danni Lyu, Yinhui Yu, Su Li, Ke Yao | | Travel Medicine and Infectious Disease. 2021; 44: 102191 | | [Pubmed] | [DOI] | | 37 |
Detection of three pandemic causing coronaviruses from non-respiratory samples: systematic review and meta-analysis |
|
| Chandan Mishra, Suneeta Meena, Jitendra Kumar Meena, Suman Tiwari, Purva Mathur | | Scientific Reports. 2021; 11(1) | | [Pubmed] | [DOI] | | 38 |
Evaluation of Nasopharyngeal and Conjunctival Swab Samples of Hospitalised Patients with Confirmed COVID-19 |
|
| Özkan Kocamis, Kemal Örnek, Nazife Asikgarip, Lokman Hizmali, Fikriye Milletli Sezgin, Yahya Sahin | | Ocular Immunology and Inflammation. 2021; 29(4): 634 | | [Pubmed] | [DOI] | | 39 |
The Presence of SARS-CoV-2 in Conjunctival Secretions of COVID-19 Patients |
|
| Emine Ciloglu, Nese Cetin Dogan, Emre Ozdemir, Hatice Kaya, Pelin Duru Cetinkaya | | Ocular Immunology and Inflammation. 2021; 29(4): 652 | | [Pubmed] | [DOI] | | 40 |
Comparative Evaluation of Tears and Nasopharyngeal Swab for SARS-CoV-2 in COVID-19 Dedicated Intensive Care Unit Patients |
|
| Ritu Arora, Ruchi Goel, Sonal Saxena, Vikas Manchanda, Mohammad Ahmad, Gaurav Gupta, Mohit Chhabra, Sumit Kumar, Tran Minh Nhu Nguyen, Payden, Palak Pumma, Kirti Saxena | | Ocular Immunology and Inflammation. 2021; 29(4): 690 | | [Pubmed] | [DOI] | | 41 |
Systematic Review of Ocular Involvement of SARS-CoV-2 in Coronavirus Disease 2019 |
|
| Kai Xiong Cheong | | Current Ophthalmology Reports. 2020; 8(4): 185 | | [Pubmed] | [DOI] | | 42 |
Phacoemulsification andCOVID-19 risk |
|
| Michael Goggin, Brendan Vote | | Clinical & Experimental Ophthalmology. 2020; 48(9): 1131 | | [Pubmed] | [DOI] | | 43 |
Are eyes the windows to COVID-19? Systematic review and meta-analysis |
|
| Rina La Distia Nora, Ikhwanuliman Putera, Dhiya Farah Khalisha, Indah Septiana, Asri Salima Ridwan, Ratna Sitompul | | BMJ Open Ophthalmology. 2020; 5(1): e000563 | | [Pubmed] | [DOI] | | 44 |
Coronavirus global pandemic: An overview of current findings among pediatric patients |
|
| Evanthia Perikleous, Aggelos Tsalkidis, Andrew Bush, Emmanouil Paraskakis | | Pediatric Pulmonology. 2020; 55(12): 3252 | | [Pubmed] | [DOI] | | 45 |
Propensity and quantification of aerosol and droplet creation during phacoemulsification with high-speed shadowgraphy amid COVID-19 pandemic |
|
| Naren Shetty, Luci Kaweri, Pooja Khamar, Nikhil Balakrishnan, Abdur Rasheed, Prasenjit Kabi, Saptarshi Basu, Rohit Shetty, Rudy M.M.A. Nuijts, Abhijit Sinha Roy | | Journal of Cataract and Refractive Surgery. 2020; 46(9): 1297 | | [Pubmed] | [DOI] | | 46 |
Quantitative shadowgraphy of aerosol and droplet creation during oscillatory motion of the microkeratome amid COVID-19 and other infectious diseases |
|
| Pooja Khamar, Rohit Shetty, Nikhil Balakrishnan, Prasenjit Kabi, Durbar Roy, Saptarshi Basu, Abhijit Sinha Roy | | Journal of Cataract and Refractive Surgery. 2020; 46(10): 1416 | | [Pubmed] | [DOI] | | 47 |
On the whereabouts of SARS-CoV-2 in the human body: A systematic review |
|
| Wim Trypsteen, Jolien Van Cleemput, Willem van Snippenberg, Sarah Gerlo, Linos Vandekerckhove, Craig B. Wilen | | PLOS Pathogens. 2020; 16(10): e1009037 | | [Pubmed] | [DOI] | | 48 |
Nosocomial COVID-19 transmission in routine ophthalmic practice—Is there new evidence? |
|
| SantoshG Honavar | | Indian Journal of Ophthalmology. 2020; 68(10): 2059 | | [Pubmed] | [DOI] | | 49 |
Commentary: Exploring the transmission of COVID-19 through the ocular surface |
|
| Joveeta Joseph | | Indian Journal of Ophthalmology. 2020; 68(6): 1018 | | [Pubmed] | [DOI] | | 50 |
To evaluate the effect of COVID-19 pandemic and national lockdown on patient care at a tertiary-care ophthalmology institute |
|
| Naresh Babu, Piyush Kohli, Chitaranjan Mishra, Sagnik Sen, Dhipak Arthur, Deepesh Chhablani, Girish Baliga, Kim Ramasamy | | Indian Journal of Ophthalmology. 2020; 68(8): 1540 | | [Pubmed] | [DOI] | | 51 |
Non-contact tonometer use during the COVID-19 pandemic |
|
| Dinesh Talwar, Harsh Kumar, Mithun Thulasidas | | Indian Journal of Ophthalmology. 2020; 68(7): 1492 | | [Pubmed] | [DOI] | | 52 |
The SARS-CoV-2, tears, and ocular surface debate: What we know and what we need to know |
|
| MohammadJaved Ali | | Indian Journal of Ophthalmology. 2020; 68(7): 1245 | | [Pubmed] | [DOI] | | 53 |
Fundus Lesions in Patients Hospitalized With COVID-19 Infection in Mumbai, India: A Retrospective Review |
|
| Salil Mehta, Prahlad Prabhudesai | | Cureus. 2020; | | [Pubmed] | [DOI] | |
|
 |
 |
|