Sept. 30, 2011 -- There are no recommended antiviral drugs to treat a highly contagious form of viral conjunctivitis called pinkeye.
Outbreaks result in millions of lost school and workdays each year in the U.S. as patients stay home to avoid infecting others while the condition improves.
Now early research from Sweden suggests that an experimental eye drop might stop viral pinkeye in its tracks and keep family members, schoolmates, coworkers, and other close contacts of patients from becoming infected.
The drops have not been studied in humans, but researchers say they are optimistic the treatment will prevent infection by tricking the virus into binding to artificial surfaces in the drops designed to mimic key cells in the eye.
Once this happens, the entrapped virus should be easily washed from the eye in tears, says researcher Ulf Ellervik, PhD, who is a professor of microbiology at Sweden’s Umea University.
“Pinkeye is a very troublesome condition,” Ellervik says. “If one family member gets it, usually everyone gets it."
Most often caused by the same virus responsible for the common cold, viral pinkeye is an infection of the part of the eye that produces mucus and tears, known as the conjunctiva.
According to the American Academy of Ophthalmology, more than 3 million school days are lost each year as a result of pinkeye.
The experimental treatment targets adenoviruses 8, 19, and 37, which cause most viral conjunctivitis.
In earlier work, the Swedish research team showed that these viruses must bind to sialic acid for infection to occur.
“What we did in this research was create an artificial surface that tricks the virus into binding to it instead of the host,” Ellervik says.
The study, which appears in the latest issue of the Journal of Medicinal Chemistry, was funded by Adenovir Pharma AB, which was founded by Umea University researchers to develop the treatment, according to the company’s web site.
Human Studies Next Step
Adenovir Pharma CEO Bjorn Dellgren says the company hopes to begin phase I human studies of the eye drops by the end of the year or early next year once the trials are approved.
He says that in animal studies the drops appeared to be safe with few side effects.
“Instead of killing the viruses, it prevents them from attaching to the binding receptor in the eye, so this should be a very safe treatment with little risk for (acquired) resistance,” he tells WebMD.
Because there is no good animal model for pinkeye, Dellgren says human studies will be needed to prove that the treatment works.
“Pinkeye is a huge problem, especially in densely populated countries such as Japan, where there are more than a million cases a year,” he says.
American Academy of Ophthalmology president-elect Ruth D. Williams, MD, says a treatment is badly needed to shorten the duration of symptoms and the time pinkeye patients are infectious to other people.
Williams is president of the Wheaton Eye Clinic in Wheaton, Ill.
She says it remains to be seen if the approach outlined in the study proves to be effective and safe.
“It will be interesting to see what the studies show,” she says. “All of us would love an effective treatment for viral conjunctivitis because it is so widespread. When it sweeps through a school or an office or a family, it is very disruptive.”