Middle ear disease

Investigators: Tulio A. Valdez, M.D., M.Sc.
Lucile Packard Children's Hospital, Stanford University

Investigator's profile

Dr. Valdez is an associate professor of pediatric Otolaryngology at the Lucile Packard Children's Hospital, Stanford University. Dr. Valdez has an interest in airway surgery and swallowing disorders. He has a special interest in the management of sinus disease in cystic fibrosis. His research includes novel imaging modalities to better diagnose ear infections one of the most common pediatric problems. His research has now expanded to include better intraoperative imaging modalities in pediatric patients to improve surgical outcomes without the need for radiation exposure. He has been collaborating with the Laser Biomedical Research Center at MIT since 1999. As a service collaborator, he adapted LBRC technologies to implement a multi-wavelength otoscope using reflectance and fluorescence images and various computer vision algorithms to achieve identification and segmentation of middle ear and tympanic membrane structures.

Significance & Background

Figure 1: (a) Light attenuation through a sample of middle ear fluid showing strong absorption in the SWIR. The absorption causes the fluid to appear black in a SWIR image (c) and translucent in visible regime (b). A model filled with fluid shows the improvement in contrast using SWIR otoscopy (e) compared with visible otoscopy (d).

The most common middle ear disease is otitis media, which refers to a continuum of inflammatory conditions of the middle ear, including acute infection. It is the second most common illness diagnosed in U.S. children, with over 8 million cases each year. Accoring to Centers for Disease Control and Prevention (CDC), over 20 million antibiotic prescriptions per year in the U.S. are for otitis media cases. However, successful diagnosis of otitis media is estimated at only 51% for U.S. pediatricians, with over-diagnosis occurring 26% of the time [1]. The resulting excess antibiotic therapy has made otitis media a primary factor in increased antibiotic resistance. On the other hand, failure to diagnose otitis media can lead to long-term hearing impairment, a delay in language acquisition, or formation of destructive skin growths in the middle ear (cholesteatoma) which require surgical excision [2,3].

Approach

Shortwave infrared (SWIR, 1-2 micrometer) and NIR Raman spectroscopy will be used for better diagnosis of middle ear disease. Adapting LBRC technology, Dr. Valdez implement an otoscope sensitive to SWIR wavelengths of light for middle ear disease diagnostics. With a first prototype, Dr. Valdez carried out a proof of concept IRB-approved study and showed that in healthy adult human ears, deeper tissue penetration of SWIR light enables improved visualization of middle ear structures through the tympanic membrane compared to conventional visible light otoscopy. In addition, Dr. Valdez has investigated the potential for detection of middle ear fluid, which has significant implications for diagnosing otitis media. Middle ear fluid shows strong light absorption between 1400-1550 nm, enabling straightforward fluid detection in a model using the SWIR otoscope. As an alternative approach, the endogenous NIR Raman spectrum from the middle ear may provide sufficient information for diagnosis. To address this need, LBRC transferred an already-established multimodal spectroscopy clinical instrument to Dr. Valdez's Lab. This instrument will collect Raman spectra from human patients' otitis media. This service project will address fundamental questions such as molecular make up of otitis media, and biochemical changes during infection. Our goal is to establish the sensitivity and specificity of the SWIR otoscope and NIR Raman spectroscopy for detection of middle ear fluid and to compare to the current diagnostic standard, pneumatic otoscopy.

Center offering

LBRC has provided instrumentation and technological knowledge for characterizing middle ear tissue and fluid to obtain a fundamental understanding of their spectroscopic properties. With LBRC advices, Dr. Valdez is developing a SWIR otoscope and develop clinical data analysis algorithm. LBRC also installed a multimodal spectroscopy (MMS) instrument in Dr. Valdez's laboratory. Since 2014 December, collected spectroscopy data has been analyzed using existing algorithms in LBRC guided by LBRC researchers.

References

  1. "Diagnostic accuracy of otitis media and tympanocentesis skills assessment among pediatricians," Eur. J. Clin. Microbiol. Infect. Dis., 22(9), pp. 519-524, Sep 2003. [ Pubmed ]
  2. "Dilemmas in Current management of complicated chronic otitis media," Indian J Otolaryngol Head Neck Surg., 71(2), PP. 155-160, June 2019. [ Pubmed ]
  3. "Updates in pediatric cholesteatoma: Minimizing intervention while maximizing outcomes," Otolaryngol Clin North Am., S0030-6665(19)30103-3, July 2019. [ Pubmed ]