On June 17, 2013, CBS News reported an unusual outbreak of pinkeye among Japanese schoolchildren. The phenomenon came to national attention when a Japanese blogger interviewed a teacher who had observed two sixth-grade students licking each other’s eyeballs in an equipment room. Confronted, they both admitted that eyeball licking—also known as “worming”—was popular in their class. In fact, it was apparently sweeping the nation.
Dr. Robert Noecker, an ophthalmologist practicing in Connecticut, explained the appeal. “The cornea is the most innervated part of the body,” he said. “That’s why it might feel good to have it licked. It’s the same thing with sucking toes.” Eyeball licking had become the new second base, when kissing gets boring.
Eyeball licking was, however, not without consequence. The Japanese teacher noted that at least ten students were wearing eye patches, presumably to hide their pinkeye. “This is a dangerous practice that has the potential to spread a number of bacteria that reside in the mouth,” Robert Glatter, an emergency physician at Lenox Hill Hospital in New York, told CBS News. Glatter was particularly concerned about chlamydia, which, according to him, “had the potential to lead to blindness if untreated.”
Bacterial infections, however, aren’t the only cause of pinkeye. Eyeball licking could scratch the cornea, causing abrasions. Or pinkeye could have been caused by viruses or a chemical reaction to enzymes and acids in the mouth or an allergic reaction. No one knew.
It took two months to figure it out.1
Covering the eye is a thin, translucent membrane that begins at the edge of the cornea and extends to the inside of the upper and lower eyelids. The medical term for this lining is the conjunctiva. When the lining gets inflamed, people say they have pinkeye. Doctors call it conjunctivitis.
Conjunctivitis is not a trivial infection. Every year, about six million Americans suffer from this condition. About 70 percent of those who suffer will visit their internist or pediatrician or optometrist or ophthalmologist; many will go to emergency rooms or urgent care centers. Most will receive a prescription for antibiotic eye drops—at a cost to the health care system of between $377 and $857 million every year.2
Conjunctivitis is so prevalent that states, schools, corporations, and day care centers have developed guidelines on how to treat it. Most of these institutions require people with conjunctivitis to receive antibiotic eye drops for at least twenty-four hours before returning to work or school.3 This requirement is designed to promote healing and prevent spread. As it turns out, it does neither. Here’s why.
The most common cause of conjunctivitis is allergies. Every year, up to 40 percent of Americans suffer from allergic conjunctivitis. Symptoms include itchy eyes; swollen eyelids; a thin, watery discharge; and a runny or itchy nose. Typically, the patient is allergic to cosmetics, contact lenses, pollen, dander, house mites, dust, pets, or other environmental allergens. Allergic conjunctivitis is most common during the spring and summer, when pollen counts are highest. And not surprisingly, it occurs in people who have other allergies, such as asthma or hay fever.4
Because allergic conjunctivitis isn’t a bacterial infection, antibiotics don’t treat it. And because it isn’t contagious, staying home from work or school doesn’t lessen the chance of its spreading. The good news is that most people with allergic conjunctivitis understand what’s happening to them. So, they’re much less likely to go to a doctor and get a prescription for an antibiotic.5
The second most common cause of conjunctivitis is viruses. In children, however, they’re the most common cause. About 80 percent of infectious conjunctivitis is caused by viruses, most commonly one called adenovirus. Whereas allergic conjunctivitis usually occurs during the spring and summer, viral conjunctivitis occurs during the winter. Symptoms include a thin, watery discharge from the eyes and cold symptoms such as runny nose and sore throat. Unlike allergic conjunctivitis, viral conjunctivitis is highly contagious; between 10 and 50 percent of people who come in contact with someone infected will also be infected.6
Because viral conjunctivitis, like allergic conjunctivitis, isn’t a bacterial infection, antibiotics don’t treat it. Also, because viral conjunctivitis usually lasts seven to ten days, staying home for only twenty-four hours before returning to work or school does little or nothing to lessen its spread.
The third most common cause of conjunctivitis is bacteria. Whereas viral conjunctivitis causes a thin, watery discharge, bacterial conjunctivitis causes a thick, pus-filled (purulent) discharge that usually lasts all day, with eyes typically matted shut in the mornings. (A simple rule for distinguishing allergic, viral, and bacterial conjunctivitis is that allergic conjunctivitis causes itching, viral conjunctivitis is accompanied by other cold symptoms, and bacterial conjunctivitis causes a thick, purulent discharge.7 Unfortunately, there’s a lot of overlap. So, it’s often hard for doctors and patients to distinguish among them.8 As a consequence, many people with allergic or viral conjunctivitis receive antibiotics.)
Because bacterial conjunctivitis is caused by bacteria, it stands to reason that antibiotic eye drops should work. However, bacterial conjunctivitis is usually a self-limited disease, meaning that people recover from it whether or not they use antibiotic eye drops. So the real question is: Do antibiotic eye drops either shorten the duration of illness or lessen symptoms? If they do, then the requirement to treat bacterial conjunctivitis with antibiotic eye drops for twenty-four hours before returning to work or school makes sense. If they don’t, then the requirement is unnecessary and, as we’ll see, potentially harmful.
The only way to determine whether antibiotic eye drops treat bacterial conjunctivitis is to do studies where one group receives antibiotic eye drops and the other receives drops that are antibiotic-free (placebo drops).
In 2012, researchers from the Centre for Population Health Sciences at the University of Edinburgh reviewed all the existing studies, writing, “We found 11 randomized controlled trials from different parts of the world which recruited a total of 3,673 participants overall. We judged two of the trials to be of high quality and we graded the remainder of poor quality.” Of the two high-quality studies, one was performed in children, the other in adults.9
The study performed in children was published in July 2005. Researchers from Oxfordshire in the United Kingdom divided 320 children with bacterial conjunctivitis into two groups. One group was given antibiotic eye drops every two hours for the first day and then four times a day until the infection had resolved. The other group was given placebo eye drops. Seven days later, the researchers found that 86 percent of the children in the antibiotic group and 83 percent in the placebo group were cured, an insignificant difference. The authors concluded, “Most children presenting with acute infective conjunctivitis in primary care will get better by themselves and do not need treatment with an antibiotic.”10
The study performed in adults was published later that year, in December 2005. Researchers from Switzerland and the Netherlands treated 160 adults with acute bacterial conjunctivitis with either antibiotic or placebo eye drops four times a day for seven days. At the end of the week, 62 percent of the treatment group and 59 percent of the placebo group were cured. Again, no significant difference. The authors concluded, “These findings do not support the current prescription practices of [antibiotic eye drops] by general practitioners.”11
Even the studies judged by the researchers at the University of Edinburgh to have been poorly done (some of which claimed that antibiotic eye drops worked) found differences that were far from dramatic. One study of adults showed a cure rate of 88 percent in the treatment group and 72 percent in the placebo group. Another in children found a cure rate of 91 percent in the treatment group and 72 percent in the placebo group. A third study, of adults and children, found a cure rate of 87 percent in the treatment group and 70 percent in the placebo group. And a fourth study, of adults and children, found a cure rate of 85 percent in the treatment group and 70 percent in the placebo group.12 In other words, most adults and children with acute bacterial conjunctivitis had completely resolved their symptoms within a week with or without antibiotic eye drops.
As a consequence of these studies, the American Academy of Ophthalmology now recommends watchful waiting for those suffering from acute conjunctivitis, whether it’s caused by bacteria or not.13 Nonetheless, about 60 percent of people in the United States with conjunctivitis receive a prescription for antibiotic eye drops.14
Because a handful of studies, even if poorly done, showed some benefit in the treatment of bacterial conjunctivitis, one could reasonably argue that the conservative choice would be to treat. After all, what’s the harm of giving a few days of antibiotic eye drops? As it turns out, the decision to treat is more dangerous than most people realize.
In the end, the requirement by many day care centers, schools, and workplaces to treat conjunctivitis with antibiotic eye drops for twenty-four hours won’t treat bacterial infections, won’t prevent the spread of viral infections, might be sensitizing, will be costly, might create antibiotic-resistant bacteria, and will only alter the normal bacteria living peacefully on the surface of your eye to protect against other bacteria that are far more dangerous. Patients are probably better off using lubricating eye drops or cold compresses to provide short-term relief of symptoms. Although this approach won’t lessen the duration of the illness, at least it won’t be harmful.
So what about the Japanese eyeball-licking story? Did investigators ever figure out what specifically was causing the conjunctivitis?
In August 2013, two months after the story broke on CBS News, David Mikkelson from the fact-checking website Snopes took a closer look. Mikkelson found that the original story had appeared in a Japanese newspaper called Bucchi News. The article was titled “The Perverted Play of Eyeball Licking Is a Hit Among Primary Schoolers.”
Bucchi News is produced by Core Magazine Co., a publishing company raided by police on suspicion of obscenity on April 19, 2013. A few days later, Core announced that it would suspend publication of two of its magazines. So, the source of the story wasn’t particularly reliable. Also, no one had ever gone back to verify the truthfulness of the teacher who had observed the eyeball licking. Queries sent to organizations of Japanese ophthalmologists and school nurses revealed that none of them had ever heard of Japanese eyeball licking, a phenomenon that was supposedly sweeping the nation. Nonetheless, the story was picked up and reported as fact by CBS News, the Guardian, and Medical Daily, among others. In short, eyeball licking wasn’t really a thing in Japan. Although it’s interesting that there is actually a medical name for it: oculolinctus.21