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A systematic review has reported ophthalmology-focused publications and findings on COVID-19 pandemic. 

A systematic review, published in the European Journal of Ophthalmology, has reported a significant number of peer-reviewed studies on ophthalmic-focused COVID-19 articles.  A study conducted on the analysis on June 12th, 2020, within the “LitCovid” database (, showed 21,364 articles for ophthalmic-focused COVID-19 reports, of which 215 publications were reviewed and analysed.  The studies included articles from ophthalmologists / researchers across 25 countries with 68 journals within 3 months of the WHO declaration of the pandemic.  While the June 12th, 2020 study identified 7.5 million individuals infected in 212 countries, the original infections were estimated as 557 cases of COVID-19 (on January 22nd, 2020) worldwide, with one case in the United States (in Seattle, Washington).   However, as of to date (February 21st 2021, the number of confirmed cases worldwide is estimated at 111.37M cases of infection, including 28.13M cases for the USA (available from “Our World in Data” where the original content is located at



Researchers of the systematic review found that the top five countries publishing ophthalmology-focused articles (China, India, USA, Italy and UK) produced 145 of the 215 (67%) articles.  According to the data, there was a total of 16 case reports/ series from eight countries reported that conjunctivitis can be the initial or the only symptom of COVID-19 infection and conjunctivitis may occur in the middle phase of COVID-19 illness. Additionally, a total of 10 hospital-based cross-sectional studies reported that between 0% and 31.6% of COVID-19 patients have conjunctivitis or other ocular conditions, with a pooled prevalence of 5.5% reported in a meta-analysis. In fact, it is known that the original whistle-blower for the international awareness of COVID-19 was Dr. Wenliang Li, an ophthalmologist in Wuhan, China.


The current systematic review in this study reported that ophthalmologists were at high risk of acquiring COVID-19 “likely due to a combination of examination proximity and contact with mucous membranes. Ophthalmologists were among the initial investigators to study the virus and to advise on both treatment and protective measures for physicians, patients, and populations”.  The review showed that the largest number of Covid publications for ophthalmic studies was in the “Prevention” category (39.3%), followed by “Treatment” category (20.1%) and “Diagnosis” (13.9%).  A further category of “Transmission,” reported 3.3% publications and the top five journals, by number of publications, were the British Medical Journal, Journal of Medical Virology, Nature,  the Lancet, and the New England Journal of Medicine.  For adjusting for population size, “Singapore had the greatest number of publications by first author for both COVID-19 publications and ophthalmology-focused”.  Interestingly, the top five countries by the number of publications per 1 million population after Singapore (52 publications), was Italy (36 publications per 1 million population), Switzerland (26 publications), Republic of Ireland (26 publications) and the UK (25 publications).