Are eyes the windows to COVID-19? Systematic review and meta-analysis.

Although the overall number of ocular manifestation and SARS-CoV-2 PCR positivity rate from ocular samples was very low, around a quarter of COVID-19-related patients with ocular manifestation presented their ocular manifestation earlier than the systemic manifestation regardless of the severity. Interestingly, SARS-CoV-2 PCR was positive from one-third of ocular samples, which could potentially be the source of infection to the respiratory tract and the environment, although the infectivity is yet to be determined.