Cholesteatoma is a condition describing the accumulation of squamous epithelium and keratinocytes within the middle ear space. There is conflicting evidence regarding the influence of socioeconomical status on the prevalence of cholesteatoma. Hospital episode statistics (HES) data detailing the numbers of cholesteatoma surgeries performed per area were compared with the Index of Multiple Deprivation 2010 (IMD 2010) data that give a statistical measure of deprivation per local health authority in the UK. Statistical analysis of this data was performed to identify correlations between prevalence of cholesteatoma and deprivation. A trend was identified showing that health authorities associated with an overall low IMD 2010 value indicating more deprived, had higher numbers of mastoid operations. Our results have found that increasing levels of deprivation are associated with greater numbers of mastoid operations and thus greater numbers of cholesteatomas. Our work suggests that there is a need for additional input in deprived areas to accommodate the increased numbers of mastoid operations and chronic middle ear disease.

Hypothesis: Optical clearing agents (OCAs) can render cartilage tympanoplasty grafts sufficiently transparent to permit visualization of middle ear structures in an operated ear using optical coherence tomography (OCT) imaging. Methods: Pieces of human tragal cartilage were treated with glycerol, a commonly used OCA. A reference reflector was imaged with OCT through the tympanoplasty as it cleared and the optical attenuation of the graft was measured. The reversibility of clearing and the dimensional changes associated with glycerol absorption were also measured. In a separate experiment, a human cadaveric temporal bone was prepared to simulate an ossiculoplasty surgery with cartilage replacement of the tympanic membrane. A partial ossicular replacement prosthesis (PORP) inserted in the ear was imaged with OCT through a 0.4mm cartilage graft optically cleared with glycerol. Main Outcome Measure: The optical attenuation of 0.4mm cartilage grafts decreased at 2.3+/−1.1 dB/min following treatment with glycerol, reaching a total decrease in attenuation of 13.6+/−5.9 dB after 7 minutes. The optical and dimensional effects of glycerol absorption were reversable following saline washout. In the temporal bone preparation, treatment of a cartilage graft with glycerol resulted in a 13 dB increase in signal-to-noise ratio and a 13 dB increase in contrast for visualizing the PORP through the graft with OCT. Conclusions: Optical clearing agents offer a potential pathway towards optical coherence tomography imaging of the middle ear in post-surgical ears with cartilage grafts.

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