Endoscopic Optical Coherence Tomography for Evaluation of Success of Tympanoplasty

Abstract

Objective: After tympanoplasty, it is often challenging to differentiate between different causes of a remaining air bone gap (ABG). Optical coherence tomography (OCT) offers a new approach for combined morphologic and functional measurements of the tympanic membrane and adjacent parts of the middle ear. Thus, it provides valuable diagnostic information in patients with a reduced sound transfer after middle ear surgery. Patient and intervention: A patient with history of tympanoplasty and a persistent ABG was investigated with endoscopic OCT before revision surgery. Main Outcome Measures: The oscillation behavior and the thickness of the reconstructed tympanic membrane was determined. The oscillation amplitudes of the inserted prosthesis were compared to a finite element model simulation and to the clinical findings and the audiometric data of the patient. Results: OCT measurements showed a reduced oscillation amplitude of the prosthesis while revealing an aerated middle ear and good coupling of the prosthesis. Transfer loss measured by OCT showed a similar progression as the ABG measured by pure-tone audiometry with a mean divergence of 4.45 dB. Conclusion: Endoscopic OCT is a promising tool for the evaluation of tympanoplasty outcome. It supports established otologic diagnostics and can help differentiating between different causes of conductional hearing loss.

In vivo microstructural investigation of the human tympanic membrane by endoscopic polarization-sensitive optical coherence tomography

“…Furthermore, an increased depth range allowed measuring the whole TM reliably and even structures behind it regardless of the individual geometry as it was considered to be of relevance during concurrent experiments. 14 , 33 …”

“…Similarly, those advantages apply for the evaluation of tympanoplasty outcome. 33 In chronic cases of otitis media, PS-OCT could support the differentiation of the inflamed membrane’s tissue from the incorporated biofilm and thus facilitate clinical staging and therapy assessment. Finally, TM reconstructions could profit from the possibility to determine the collagen content and its thickness distribution for creating improved artificial replica.…”

Data-informed imaging: how radiography and shape models support endoscopic OCT imaging of the middle ear

“…As X-ray-based CBCT imaging uses ionizing radiation and is thus harmful, it is limited in its application and repetition. In clinical cases such as tympanoplasty 15 or post-surgery evaluation of a CI placement, OCT is a promising support for the established diagnostics and potentially a replacement for radiographic examinations under certain conditions. 16 However, the evaluation of the volumetric data is challenging and time consuming, hampering the application of OCT in clinical daily routine.…”

“…after inserting a cochlea implant (CI) into the inner ear to treat sensorineural hearing loss. Although OCT is a promising diagnostic tool in those cases 15,16 with the advantage of non-ionizing radiation and unlimited repeatability, the high scattering and absorption of bone in the NIR sets the current limits.…”

Geometrically accurate real-time volumetric visualization of the middle ear using optical coherence tomography

“…In addition to structural imaging, phase-sensitive OCT Doppler vibrometry (OCT-DV) techniques can measure vibrations of middle ear structures in response to sound with sub-nanometer sensitivity [2,3], providing new diagnostic information highly relevant for distinguishing pathologies of the middle ear that result in conductive hearing loss [4]. ME-OCT has been used successfully to identify stapes fixation in a patient population [4], to assess the state of a post-operative ear [5], to detect distortion product otoacoustic emissions as vibrations along the ossicular chain [3], to image cholesteatoma [6], to detect cochlear implant retraction [7] and to image dimeric tympanic membrane segments [8].…”