Wideband absorbance tympanometry: a novel method in identifying otosclerosis.

PURPOSE

The purpose of the study was to know whether the wideband absorbance measurements can be a useful tool to identify ears with otosclerosis. The present study analyzed WBA measurements and highlighted its effectiveness in identifying ears with otosclerosis and differentiating from healthy normal ears.

METHODS

The study included 42 ears with otosclerosis which were compared with an equal sample size of healthy normal ears. WBA across frequencies and wideband average absorbance (375-2000 Hz) at the peak and ambient pressure, and resonance frequency were measured and analyzed.

RESULTS

Results showed that WBA levels increased with an increase in frequencies up to 2000 Hz and decreased thereafter, both in the otosclerosis and healthy normal ears. The mean WBA in the otosclerosis group was significantly lower in the 250-2000 Hz frequency range than in the healthy normal ear group. The WBA values at ambient pressure reduced significantly up to 500 Hz for the healthy normal ear group and 1500 Hz for otosclerosis group, compared with peak pressure. Further, the analysis of wideband average absorbance at ambient pressure showed reduced absorbance (0.35) and higher resonance frequency (1350.33 Hz) in the otosclerosis group compared with the healthy normal ear group (0.60 and 930.14 Hz, respectively). ROC analysis indicated that WBA is suitable for identifying otosclerotic ears and also in differentiating from healthy normal ears based on WBA values from 250 to 1500 Hz. High diagnostic values of WBA (> 90% sensitivity and specificity) were observed at a frequency of 1000 Hz.

CONCLUSIONS

The inclusion of WBA into clinical routine test procedures could be a useful tool for detecting otosclerosis. Further research is required to validate its clinical use in combination with other middle ear measures.