The impact of the coronavirus on the human body and its precise mechanism is constantly in flux as more information comes to light. On March 6, the American Academy of Ophthalmology reported that conjunctivitis is rare in cases of COVID-19 and that only 1% to 3% of patients would develop the viral pink eye.¹ But a new study out of China shows that the infection often leads to a variety of other ocular symptoms, and that they may appear just before the onset of respiratory symptoms.²

The confusion over the virus’s connection to ocular symptoms is understandable—as a class, coronaviruses are rarely associated with clinically significant conjunctivitis (although the HCoV-NL63 coronavirus outbreak of 2004 and 2005 saw conjunctivitis in 17% of confirmed cases).^3,4

The new research included 56 confirmed COVID-19 patients ranging in age from 24 to 68 years old who were discharged from the isolation ward of the hospital and had recovered well enough to return home.² Fifteen subjects (27%) reported ocular symptoms in the course of COVID-19, including sore eyes, itching, foreign body sensation, tearing, redness, dry eyes, eye secretions and floaters.² Among them, six (11%) presented with ocular symptoms before onset of fever or respiratory symptoms.² Of those six subjects, four reported the appearance of ocular symptoms one to seven days before the onset of fever or respiratory symptoms, while the remaining two subjects were uncertain about when their ocular symptoms appeared.²

Only two subjects developed conjunctivitis after hospitalization, and in one of those two, conjunctival swab samples showed positive virus RNA detection.² “It is well established that for most coronavirus infections, clinically significant conjunctivitis is rarely present,” the researchers noted in their paper. “The SARS-CoV-2 was found to infect the mucosa membrane epithelium and even lymphocytes, which are both abundant in ocular surface tissue.”²