Conjunctivitis: Can antibiotics help?

Photo of a woman using eye drops (PantherMedia / Peter Jobst)

Simple cases of conjunctivitis often clear up within ten days, even without any treatment. If the conjunctivitis is caused by bacteria, antibiotic eye drops or creams can help make it go away a bit faster. If it's caused by a virus, antibiotics don't help.

Conjunctivitis is often caused by germs such as viruses or bacteria. The symptoms of viral and bacterial conjunctivitis are very similar, making it difficult to tell them apart. Doctors generally don't test to see which germs are causing the infection. But many prescribe antibiotic eye drops or creams just in case, even though these medications are only effective against bacteria.

Research on antibiotics for treating conjunctivitis

Researchers from England and the Netherlands looked at studies on the treatment of conjunctivitis with antibiotics. They wanted to find out whether antibiotics help in the treatment of ordinary conjunctivitis, and what possible disadvantages they might have.

The researchers only analyzed the results of studies that compared at least two groups of people. One group of participants used antibiotic eye drops or creams. The other group used non-antibiotic eye drops or creams.

The researchers only included studies in which the participants were randomly assigned to one of the treatment groups. This kind of study, called a randomized controlled trial, delivers the most reliable results.

The researchers found a total of eleven studies involving nearly 3,700 children and adults.

Antibiotics can speed up recovery

Analysis of the studies shows that acute conjunctivitis goes away somewhat faster when antibiotics are used. The following results were found for people who went to a family doctor or eye specialist because of conjunctivitis:

In other words, antibiotics helped to speed up the recovery in 10 out of 100 people within this time.

None of the studies reported on side effects of the antibiotics. They also did not look into whether antibiotics lower the risk of the infection spreading.