Optical coherence tomography of the oval window niche

OBJECTIVE: Optical coherence tomography was used to study the stapes footplate, both in cadaveric temporal bones and during middle-ear surgery. MATERIALS AND METHODS: Optical coherence tomography was conducted on five temporal bone preparations (from two children and three adults) and in eight patients during middle-ear surgery. A specially equipped operating microscope with integrated spectral domain optical coherence tomography apparatus was used for standard middle-ear surgical procedures. RESULTS: This optical coherence tomography investigation enabled in vivo visualisation and documentation of the annular ligament, the different layers of the footplate and the inner-ear structures, both in non-fixed and fixed stapes footplates. In cases of otosclerosis and tympanosclerosis, an inhomogeneous and irregularly thickened footplate was found, in contrast to the appearance of non-fixed footplates. In both fixed and non-fixed footplates, there was a lack of visualisation of the border between the footplate and the otic capsule. CONCLUSIONS: Investigation of the relatively new technology of optical coherence tomography indicated that this imaging modality may assist the ear surgeon to assess the oval window niche intra-operatively.