Does the novel coronavirus use the ocular surface as an entrance into the body or as an infection site?

Remzi Karadag, Alp Kayiran, Christopher J. Rapuano

This study attempts to review whether the coronavirus disease-2019 (COVID-19) is transmitted through the ocular surface and examine the symptoms and signs of ocular disease. Considering that COVID-19 is transmitted by airborne droplets and close contact with infected individuals, we will also review the conditions to which eye clinics and ophthalmologists should pay attention to prevent the transmission of the disease. Although some researchers have argued that COVID-19 transmission cannot occur through the ocular surface, most of them are of the opinion that the ocular surface is a potential pathway of transmission. Until date, ocular signs and symptoms have been rarely reported in the COVID-19 patients. However, there are case reports of conjunctivitis as the first, and rarely, the only clinical symptom of the disease. In addition, low coronavirus RNA positivity can be detected in the ocular surface samples. Further laboratory and clinical investigations are needed to ascertain whether the ocular surface is one of the potential transmission pathways through which severe acute respiratory syndrome-coronavirus 2 can gain entry into the human body.