United States researchers have found that the virus responsible for COVID-19 can penetrate the blood-retinal barrier (BRB).
The finding could have significant insights for understanding the impact of the virus on eye health.
While SARS-CoV-2 is well known for its respiratory effects, the virus has also been observed causing a range of ocular abnormalities and vision impairment in COVID-19 patients.
The presence of viral remnants in various ocular tissues and fluids from COVID-19 patients has led to an assumption that SARS-CoV-2 may be transmitted through the eyes.
…findings from this study shed light on the role of BRB in SARS-CoV-2 ocular tropism and the role of eyes in viral transmission
However, the researchers found that SARS-CoV-2 ocular tropism is through cells lining the BRB. SARS-CoV-2 not only infects the various parts of the eye via systemic exposure but also induces a hyperinflammatory immune and antiviral response in the retina, the researchers said.
“Unexpectedly, the corneal epithelium was found to be resistant to SARS-CoV-2 infection, and ocular exposure of SARS-CoV-2 failed to cause lung pathology and moribund illness.
“Cells lining the BRB showed induced expression of viral entry receptors and enhanced susceptibility towards SARS-CoV-2-induced cell death, which is further potentiated with comorbidities such as hyperglycemia.
“Our findings from this study shed light on the role of BRB in SARS-CoV-2 ocular tropism and the role of eyes in viral transmission,” the researchers said.
The study was published in PLOS Pathogens.1
Reference
- Monu, M., Ahmad, F., Singh, P.K. et al., SARS-CoV-2 infects cells lining the blood-retinal barrier and induces a hyperinflammatory immune response in the retina via systemic exposure, PLOS Pathogens (2024). DOI: 10.1371/journal.ppat.1012156.
