Presence of SARS-CoV-2 on the conjunctival mucosa in patients hospitalized due to COVID-19: Pathophysiological considerations and therapeutic implications ANDRÁS VÉGH 1 p , ANITA CSORBA 1 , ÁKOS KOLLER 2,3 , BEHNAM MOHAMMADPOUR 1 , PETRA KILLIK 1 , LILLA ISTVÁN 1 , MÁRTON MAGYAR 1 , TERÉZ FENESI 1 and ZOLTÁN ZSOLT NAGY 1 1 Semmelweis University, Department of Ophthalmology, Budapest, Hungary 2 Semmelweis University, Translational Medicine Institute, Budapest, Hungary 3 Hungarian University of Sports Sciences, Research Center for Sports Physiology, Budapest, Hungary Received: January 31, 2022 • Revised manuscript received: June 29, 2022 • Accepted: August 15, 2022 © 2022 The Author(s) ABSTRACT Introduction: Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in a worldwide pandemic, due to its great capacity to invade the human body. Previous studies have shown that the primary route of invasion of this virus is the human respiratory tract via the co-expression of ACE2 receptor and TMPRSS2, a serine protease on the cellular surface. Interestingly, this condition is present not only on the respiratory epithelium but on the conjunctival mucosa, as well. Thus, we hypothesized that SARS-CoV-2 is present on the conjunctival mucosa. Aim: To prove that SARS-CoV-2 can be detected in the conjunctiva. Methods: Previously naso- pharyngeal swab-sample based real-time polymerase chain reaction (PCR) positive COVID-19 infected patients were selected at the COVID Care Centers of Semmelweis University, Budapest, Hungary. The study was approved by the ethical committee of Semmelweis University. During their recovery, both nasopharyngeal and conjunctival swab-samples were taken and PCR method was used to detect the presence of SARS-CoV-2 RNA. Appropriate statistical analysis was performed. Results: The study popu- lation consisted of 97 patients, 49 females (50.5%) and 48 males (49.5%), with a mean age of 67.2 ± 11.9 years. During recovery, with nasopharyngeal swabs, the PCR test was positive in 55 cases (56.70%), whereas p Corresponding author. Mária utca 39, Budapest H-1085, Hungary. E-mail: vegh.andras@med.semmelweis-univ. hu Physiology International DOI: 10.1556/2060.2022.00113 Unauthenticated | Downloaded 11/23/22 11:55 AM UTC