Among individuals hospitalized with coronavirus disease 2019 (COVID-19) in Suizhou, China, the proportion of patients who wore glasses for extended daily periods was smaller than the general population.
Among individuals hospitalized with coronavirus disease 2019 (COVID-19) in Suizhou, China, the proportion of patients who wore glasses for extended daily periods was smaller than the general population, suggesting daily eyeglass wearers may be less susceptible to COVID-19. Findings of the cohort study were published in JAMA Ophthalmology.1
Although respiratory droplets are the main source of transmission for COVID-19, the eye is considered an important route of infection. Preliminary research first published in April found evidence that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, may be transmitted through the eye.
In China, prevalence of myopia (nearsightedness) is estimated to be above 80%, meaning wearing eyeglasses is common among Chinese individuals of all ages. “However, since the outbreak of COVID-19 in Wuhan in December 2019, we observed that few patients with eyeglasses were admitted in the hospital ward,” authors wrote.
To better understand the association between wearing eyeglasses and COVID-19 infection, researchers analyzed data from all inpatients admitted to Suizhou Zengdu Hospital between January 27 and March 13, 2020. During their stay, participants were asked about the reason they wore eyeglasses, the length of time they wore glasses during daily activities, and whether they wore contact lenses or had undergone refractive surgery.
Researchers hypothesized eyeglasses may prevent or discourage wearers from touching their eyes, “thus avoiding transferring the virus from the hands to the eyes.”
Long-term wearers were classified as individuals who wore glasses more than 8 hours each day. In total, 276 patients were included in the study with a median (interquartile range) age of 51 (41-68) years. The majority of patients were male (56.2%) while most were moderately ill with COVID-19. Fourteen patients (5.1%) were classified as severely ill.
Investigators used data from the Research on Chinese Student Physique and Health Study to determine population myopia rates. Although the study was conducted in 1985, results showed “the mean rate of myopia among students aged 7 to 22 years in Hubei Provence was 31.5%. By 2020, these students were aged 42 to 57 years, which is close to the median age of our patients with COVID-19.”
Of the 276 participants:
“According to available statistics, nearly 1% to 12% of patients with COVID-19 have ocular manifestations, SARS-CoV-2 was detected in tears or the conjunctival sacs of patients with COVID-19, and some ophthalmologists were reported to be infected during routine treatment,” authors wrote. Based on these findings, researchers recommend individuals avoid touching their eyes with hands and wash hands frequently.
A small sample size and in addition to the fact the proportion of wearers of eyeglasses was based on data from previous literature and was not calculated from current local populations mark limitations to the study.
Furthermore, “the myopia rate obtained in previous studies included a small number of people with myopia who did not wear eyeglasses. Information on these people was lacking and partly affected the integrity and validity of our data,” researchers cautioned. Future studies clarifying the underlying reasons wearing eyeglasses may decrease susceptibility to COVID-19 are warranted.
In an accompanying editorial2 to the brief report, Lisa L. Maragakis, MD, MPH, noted individuals must be careful to avoid inferring a causal relationship from a single observational study. As there may be an alternative explanation for the findings, “we would be incorrect to conclude that wearing eyeglasses reduces a person’s susceptibility to COVID-19 or to recommend that people should begin wearing eye protection in public to prevent COVID-19 acquisition,” Maragakis wrote.
Because the study took place in the early stages of the pandemic, descriptive statistics do not account for data on increased rates of hand washing or physical distancing that have be shown to mitigate the risk of COVID-19 in the months since. “This makes it difficult to assess any incremental benefit of eye protection in public settings over and above these basic interventions that are now the mainstay of COVID-19 prevention.”
Maragakis is the senior director of infection prevention at the Johns Hopkins Health System an associate professor of medicine at the Johns Hopkins School of Medicine.