Pink eye needs 'to run its course,' say ophthalmologists advising against antibiotics

Antibiotic eye drops are often prescribed for pink eye, but a new study warns that's usually the wrong way to go.

Majority of people with conjunctivitis have viral form that does not respond to antibiotics

'My left eye has conjunctivitis,' Justin Bieber said on Instagram in May. (Instagram)

People with red, itchy eyes and light sensitivity from pink eye are often prescribed antibiotic eye drops that are rarely needed and in some cases prolong symptoms, ophthalmologists say.

Pink eye, or conjunctivitis, is an inflammation of the lining of the inside of the eyelid and white part of the eye. It can be caused by allergies, infections from bacteria or viruses, or just mechanical irritation.

Researchers say 60 to 80 per cent of the six million people diagnosed with conjunctivitis each year in the U.S. have a viral form that does not respond to antibiotics.

"The most important thing is just doing a lot of handwashing and just giving it a chance to run its course," said Dr. Joshua Stein, an associate professor of ophthalmology and visual sciences at the University of Michigan and Kellogg Eye Center.  

Prescription can cost $200 US

As Canadian singer Justin Bieber discovered this spring and shared on Instagram, conjunctivitis is highly contagious. It usually clears up within seven to 14 days on its own.

Not sharing towels and linens can also help curb spread at home.  

In the June online issue of Ophthalmology, Stein and his co-authors looked at more than 340,000 people across the U.S. who were diagnosed with acute conjunctivitis over a 14-year period.

Of these, 58 per cent filled a prescription for antibiotic eye drops that can cost up to $200 US.

Patients sometimes expect medication

What's more, nearly one in five antibiotic-drop users filled prescriptions for antibiotic-corticosteroids that are not recommended in most cases of acute conjunctivitis because they can worsen underlining viral infections. If taken for long periods, the drops can increase the risk of cataracts and glaucoma, the researchers said.

Antibiotic eye drops for acute conjunctivitis are often not needed. (Melanie Glanz/CBC)

Stein said part of what's driving the antibiotic prescribing is sometimes patients come to a health-care provider expecting a medication. Patients are often unaware of the harmful side-effects of antibiotics and may falsely believe that antibiotics are needed for the infection to clear.

"They may leave disappointed if they're just being told use some cold compresses and artificial tears."

School policies in Canada and the U.S. that encourage or require antibiotics before a child can return also drive up prescribing, Stein said.

'Regulations need to be revisited'

If it's caused by a virus and not by bacteria, then it's not really achieving the purpose of reducing contagion and spread at schools and workplaces. "We think that some of these regulations need to be revisited," Stein said.

Throwing antibiotics "at every red eye" is abusing antibiotics, but it happens and is underestimated, said Dr. Daniel Flanders, a pediatrician in Toronto who was not involved in the study.

"Papers like this are really important to demonstrate the manner in which we as physicians are not doing our jobs well enough and not saving the use of antibiotics for the times when it's only needed," Flanders said.

Stein and his colleagues found the odds of prescribing antibiotics were two to three times higher by urgent-care physicians, pediatricians, internists and family practitioners compared with ophthalmologists. Stein said he suspects that's because non-eye-care providers are less familiar with the fact that most acute conjunctivitis is not caused by bacteria.

Bacterial or viral?

There is a swab-based test to help health-care providers to distinguish bacterial from some viral conjunctivitis. In his practice, Stein said he reserves the test for cases that don't improve on their own or are atypical.

Health-care providers diagnose conjunctivitis by taking a history and examining the eye. In general, bacterial pink eye causes some inflammation of the eyelids and there's typically a pus-type, sticky discharge with lots of yellow-green secretions, according to CNIB's website. But that isn't a "slam dunk" for a bacterial cause, Flanders said.  

Ophthalmologist Dr. Marisa Sit of Toronto Western Hospital said most cases are seen by primary care physicians or pediatricians. If the patient starts to have very blurry vision, then they might be referred to an ophthalmologist.

Even for eye specialists, it can sometimes be difficult to distinguish different types of conjunctivitis.

"The conjunctiva may look inflamed or swollen," Sit said. "We might be able to tell the difference whether it's bacterial or viral. To see that we have to use our specialized equipment."

"One way around overprescribing antibiotics might be to simply wait," she said.


With files from CBC's Christine Birak and Melanie Glanz


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