Conjunctivitis, or pink eye, is an inflammation of the membrane covering the white part of the eye and the inner surface of the eyelids. It typically causes redness, watering, and irritation. Since the COVID-19 pandemic began, people have questioned whether the SARS-CoV-2 virus can cause this infection. This article examines the link between pink eye and COVID-19, exploring the biological mechanisms and providing guidance on symptoms.
Confirming the Connection: Pink Eye and SARS-CoV-2
Pink eye is a recognized symptom of SARS-CoV-2 infection, though it is infrequent. Studies show the prevalence of ocular symptoms varies widely among COVID-19 patients. In adults, the rate of conjunctivitis is typically between 1% and 3% of cases, making it an atypical manifestation compared to respiratory symptoms. However, conjunctivitis is the most commonly reported ocular issue when the eyes are affected.
This symptom usually appears alongside common signs of COVID-19, such as fever, cough, and fatigue. The inflammation is typically viral conjunctivitis, presenting with watery discharge and redness. It often starts in one eye before spreading to the other. Certain variants, like the Omicron subvariant Arcturus (XBB.1.16), have been associated with higher reports of conjunctivitis, particularly in pediatric cases.
How the Virus Affects the Eyes
SARS-CoV-2 causes pink eye because specific protein structures are present on ocular tissue. The virus gains entry into human cells by binding to the Angiotensin-Converting Enzyme 2 (ACE2) receptor. These ACE2 receptors, along with the TMPRSS2 enzyme, are expressed on the epithelial cells of the conjunctiva.
This allows the virus to directly infect the eye’s surface tissue, similar to how it infects the respiratory tract. The resulting infection triggers an inflammatory response. This localized inflammation produces the classic symptoms of viral conjunctivitis, including redness, soreness, and excessive tearing.
Identifying the Cause and Next Steps
Although SARS-CoV-2 can cause conjunctivitis, it is important to understand that other causes are far more common. Pink eye is most frequently caused by common adenoviruses, bacteria, or seasonal allergies. Viral conjunctivitis from COVID-19 is visually indistinguishable from that caused by other viruses. Key differences can help differentiate the cause; a thick, pus-like discharge often indicates a bacterial infection, while intense itching is a hallmark of allergic conjunctivitis.
If you develop pink eye, isolation protocols are advisable because most forms of viral conjunctivitis are highly contagious. If eye symptoms are accompanied by other signs of a respiratory illness, such as a sore throat, fever, or body aches, consider testing for COVID-19. Contact a healthcare provider if symptoms are severe, show no improvement, or if you experience severe eye pain, sensitivity to light, or sudden changes to your vision. A medical evaluation can rule out other, more serious conditions.