**6. Transmission**

Health care workers are at special risk for SARS-CoV-2 infection due to high incidence of long term end repeated exposure, protected as well as unprotected.

Conjunctiva and conjunctival discharge is a possible route of SARS-Cov-2 transmission.

Presence of virus particles in conjunctival swabs, tear swabs and conjunctival scrappings has been investigated in several studies with different outcomes. Case series from Singapore first detected SARS-CoV in tears of 3of 36 tested patients sampled within 9 days of onset of disease (in the early phase). This case series has important implications for the ophthalmology practice since reported with the detection of the SARS-CoV from tears [18].

Considering the new and ongoing epidemic several studies were conducted in China and analyzed tears and conjunctival secretions from SARS-Cov-2 infected patients. In study conducted in Wuhan 2.8% of tested patients (of 72 tested) were confirmed SARS-CoV-2 RNA in conjunctival discharge [19] while in the study conducted in Hangzhou (on 30 patients) only one sample tested positive on presence of visus in PCR results [20]. Study from Wuhan investigated 67 cases of probable or confirmed COVID-19 infection. They found positive PCR result in one sample of conjunctival swab and two possible positive samples. None of the tested patients had ocular symptoms. The sample was taken from one patient with symptoms of conjunctivitis and the PCR test was negative [21].

The study conducted in Italy (Lombardia) SARS-CoV-2 was found in 57.1% of patients on the ocular surface with a variability of viral load from both eyes [22]. The infectivity of the material was not determined but the results suggested that the test can be positive in conjunctival swab and negative in nasopharingeal swab.

Authors from Croatia emphasize the importance of early detection of possible ocular manifestations and the need for precaution in order to prevent transmission through ocular secretions [23].

Besides frequent hand washing they emphasize the need for immediate disinfection of ophthalmic instruments, especially those in direct contact with patient's mucosal membranes.

Considering the several study results we can presume that the conjunctiva and ocular surfaces are rearly detected in presence of SARS-Cov-2 but have to be considered and investigated in the future.
