New imaging device may lead to improved treatment of chronic ear infections

Prototype of a new device that can see biofilms behind the eardrum, for use in the diagnosis and treatment of otitis media. Photo courtesy of the University of Illinois New Bureau.

CHAMPAIGN, lL—Otitis media, an infection of the middle ear, is one of the most common causes of temporary hearing loss among children. The condition often interferes with their ability to learn. Moreover, children who suffer from chronic ear infections that are not properly treated run the risk of developing permanent hearing loss

That’s why new technology designed to improve the diagnosis and treatment of ear infections looks like good news for kids, their parents, teachers, pediatricians, and audiologists. Researchers at the University of Illinois have invented a medical imaging device, which was the subject of an article in last week’s online edition of Proceedings of the National Academy of Sciences.

Patients who suffer from chronic ear infections often have a buildup of film of bacteria or other microorganisms behind the eardrum, very similar to dental plaque that forms on unbrushed teeth. Finding and monitoring these biofilms in the ear is important to diagnosis and treatment of chronic otitis media. However, doing this has been difficult. A pediatrician using a standard otoscope sees only the surface of the eardrum, and cannot detect a biofilm that is hidden behind the eardrum. But the newly developed imaging device allows physicians to look behind the eardrum and determine if there is biofilm lurking there.

The University of Illinois researchers who came up with the new device were led by Stephen Boppart, a professor of electrical and computer engineering.

In an interview with Liz Ahlberg of the University of Illinois News Bureau, Boppart said, “We know that antibiotics don’t always work well if you have a biofilm, because the bacteria protect themselves and become resistant. In the presence of a chronic ear infection that has a biofilm, the bacteria may not respond to the usual antibiotics, and you need to stop them. But without being able to detect the biofilm, we have no idea whether or not it’s responding to treatment.”

The device employs a technique called optical coherence tomography (OCT), a non-invasive imaging system devised by Boppart’s group. It uses beams of light to collect high-resolution, three-dimensional tissue images, scanning through the eardrum to the biofilm behind it.

A scan takes only a fraction of a second, especially valuable for use with very young patients who may not want to stay still. The images not only reveal the existence of a biofilm, but they also show its thickness and its position.

To test their device, the University of Illinois group worked with clinicians at Carle Foundation Hospital in Urbana, IL, to scan patients with diagnosed chronic ear infections, as well as patients with normal ears. The device identified biofilms in all patients with chronic infections, while none of the normal ears showed evidence of biofilms.

Welch Allyn, a leading manufacturer of otoscopes, is collaborating on the project, which was funded by the National Institutes of Health. It is hoped that the hand-held prototype device can be made more compact, easy to use, and affordable.