Emerging Use of Optical Coherence Tomography in Otolaryngology

Imaging the airways of pediatric patients may allow us to determine why the child has an airway problem and determine the prognosis for recovery, said Dr. Armstrong. Is the narrowing of the airway due to edema, scar tissue, or cartilage? Is it reversible or no? Will the child need a tracheotomy? These are some of the questions we are able to answer by using OCT.

Polarization-sensitive OCT (PS-OCT), which is more sensitive to collagen fiber orientation and density, has been used in conjunction with OCT to image human vocal fold tissue in vivo in a study at Mass General.7

The purpose of our study was to test the technology’s ability to better delineate microscopic vocal fold structure and/or disease, said Adam M. Klein, MD, who is now Assistant Professor at the Emory Voice Center in the Department of Otolaryngology-Head and Neck Surgery at Emory University in Atlanta. Although we were successful at imaging the human vocal folds in the asleep and awake patient, there is still a substantial amount of development that must occur before these technologies can be a viable clinical tool.

Not Ready for Prime Time

Whenever I explain the concept of OCT and its potential in the field of otolaryngology, most ENTs think it’s very exciting and wonder why we don’t have a self-contained unit ready for them to use right now in their office, said Dr. Armstrong.

Although things are progressing faster than we predicted, we are still in the early stages of development, he continued. For other specialties, such as ophthalmology, OCT is fairly straightforward, as the eye is easily accessible for observation. Otolaryngology, on the other hand, requires more mechanical expertise, as we are trying to put a probe down someone’s throat, while dealing with patient and physician movements, vibrations, and gag reflexes.

Each time we use OCT, we have to have an engineer present, tweaking the equipment. We have had to overcome many technical hurdles, like delivery, access, ergonomics, resolution and speed of image acquisition, just to get this far. Further refinement of the prototype is necessary before it can be commercially available.

One of the biggest problems we had initially was condensation on the optical probe, said Dr. Chen. The hot air from breathing condenses on the window surface and smears the image. We developed a special coating to solve the problem.

Right now, we sterilize the probe each time, but in the future, a disposable device would be better, he added.