Optical Coherence Tomography of the Tympanic Membrane and Middle Ear: A Review

Abstract

Objective To evaluate the recent developments in optical coherence tomography (OCT) for tympanic membrane (TM) and middle ear (ME) imaging and to identify what further development is required for the technology to be integrated into common clinical use. Data Sources PubMed, Embase, Google Scholar, Scopus, and Web of Science. Review Methods A comprehensive literature search was performed for English language articles published from January 1966 to January 2018 with the keywords "tympanic membrane or middle ear,""optical coherence tomography," and "imaging." Conclusion Conventional imaging techniques cannot adequately resolve the microscale features of TM and ME, sometimes necessitating diagnostic exploratory surgery in challenging otologic pathology. As a high-resolution noninvasive imaging technique, OCT offers promise as a diagnostic aid for otologic conditions, such as otitis media, cholesteatoma, and conductive hearing loss. Using OCT vibrometry to image the nanoscale vibrations of the TM and ME as they conduct acoustic waves may detect the location of ossicular chain dysfunction and differentiate between stapes fixation and incus-stapes discontinuity. The capacity of OCT to image depth and thickness at high resolution allows 3-dimensional volumetric reconstruction of the ME and has potential use for reconstructive tympanoplasty planning and the follow-up of ossicular prostheses. Implications for Practice To achieve common clinical use beyond these initial discoveries, future in vivo imaging devices must feature low-cost probe or endoscopic designs and faster imaging speeds and demonstrate superior diagnostic utility to computed tomography and magnetic resonance imaging. While such technology has been available for OCT, its translation requires focused development through a close collaboration between engineers and clinicians.

Assessing the Effect of Middle Ear Effusions on Wideband Acoustic Immittance Using Optical Coherence Tomography

“…To further examine the capability of OCT as a diagnostic tool, a portable and hand-held OCT system was integrated with an otoscope to quantify the presence of MEEs, middle ear biofilms, and the thickness of the TM in the exam room and the operating room ( Nguyen et al 2013 ; Hubler et al 2015 ; MacDougall et al 2015 ; Monroy et al 2015 , 2018 ). These studies have shown that OCT can quantitatively characterize middle ear conditions for both adult and pediatric subjects, and noninvasively provide helpful diagnostic criteria for differentiating types and stages of OM ( Monroy et al 2015 ; Tan et al 2018 ). Furthermore, functional measurements have been possible with OCT, including quantifying TM displacements with pneumatic pressure inputs ( Shelton et al 2017 ; Won et al 2018 ), assessing TM vibrational patterns with sound ( Chang et al 2013 ; MacDougall et al 2016 ), and estimating MEE viscosity ( Monroy et al 2017a ).…”

“…A recent surgical follow-up study also demonstrated that OCT can detect the clearance of biofilms as well as the presence of biofilms and MEEs, which correlated well with clinical findings from otologists ( Monroy et al 2017b ). Furthermore, several review articles suggest that OCT middle ear imaging has advantages over other diagnostic imaging tools, such as magnetic resonance imaging, computed tomography, and ultrasound, due to noninvasiveness, high speed, and high resolution, extending the diagnostic capabilities in otology ( MacDougall et al 2015 ; Ramier et al 2018 ; Tan et al 2018 ).…”

Emerging Technologies for the Diagnosis of Otitis Media

“…This has become a widely applicable technique used in many fields since the early 1990s and is also currently used for the objective assessment of MEE presence and assessing its viscosity in OM cases. 25…”

Intra-Operative Optical Coherence Imaging of In-Vivo Chronic Otitis Media Followed by Post-Operative Audiogram Assessments

“…Besides its intra-operative applications, OCT techniques over the last two decades have been promisingly recognized for ophthalmology [21][22][23], dentistry [24][25][26][27], dermatology [28][29][30][31], and otorhinolaryngology [32,33]. The high-resolution of OCT (1-15 μm ) has vital merits in otology over other medical imaging methods, such as its ability to image a thin sub-surface, low contrast TM, and complicated middle ear structures compared to that of the computed tomography (CT) (50 μm), micro-magnetic resonance imaging (μMRI) (10-100 μm), and positron emission tomography (PET) (1-2 mm) [34,35]. The unique features of OCT (non-destructive, real-time, and threedimensional imaging) have a major impact on the surgical maneuver and its recent integration with the microscope [20,[36][37][38][39][40][41].…”