# Optical imaging technologies to identify residual cholesteatoma and improve ossiculoplasty outcomes

> **NIH NIH R01** · UNIVERSITY OF SOUTHERN CALIFORNIA · 2020 · $672,471

## Abstract

There are a number of diseases and conditions in the middle ear that cause hearing loss in both children and
adults. In children it is particularly important to expedite interventions to restore hearing since it negatively
impacts language development and academic performance. An example is cholesteatoma, a benign lesion due
to abnormal skin growth in the middle ear which facilitates erosion of bone, including the ossicles, causing
permanent damage. The preferred surgical approach comes with a relatively high risk of both recurrent and
residual lesions (~10%). While the initial diagnosis is typically straight forward because of the size of the lesion
when the patient seeks medical care, identifying residual cholesteatoma after the initial resection has been
performed is difficult even using advanced MRI and CT techniques. Consequently, “second look” surgeries are
frequently preformed to verify that the middle ear is lesion free. An imaging solution able to identify
cholesteatoma lesions in the clinic could substantially reduce the number of second look surgeries and their
associated costs and potential co-morbidities (e.g. sensorineural hearing loss, vertigo and surgical trauma to
the facial nerve).
Disruption of the ossicular chain due to cholesteatoma or other etiologies (e.g. trauma, chronic otitis media,
osteosclerosis) is commonly treated with ossicular replacement surgery to restore hearing. Unfortunately, the
outcomes vary greatly. While the variation is not entirely understood, an accepted contributing factor is the
choice of the length of the prostheses with loose fitting prostheses performing significantly better than tight
fitting prostheses. However, there is currently no imaging technology that can provide pre- or intra-surgical
quantitative guidance on optimal prosthetic length. Scar tissue formation around the prosthesis can also
adversely affect hearing outcomes, and there is no reliable way to identify this problem. Therefore, if the
outcome is poor it is often difficult to determine the cause and whether a revision surgery is indicated.
Advanced optical imaging tools based on Optical Coherence Tomography (OCT) can largely fill this gap in
imaging technology thus providing improved diagnostics, leading to better outcomes and lower health care
costs. OCT has both the spatial and temporal resolution to measure the morphological features and the
function of the ear. The challenge with utilizing OCT for interrogating the middle ear space is access.
OCT can penetrate roughly 2 mm into tissue, hence access to the middle ear for imaging must be made via the
ear canal or Eustachian tube. The technology development proposed here is directed at overcoming the access
issue and enabling comprehensive functional and morphological imaging of the middle ear space. A set of pilot
studies will address validation of our approach for specific pathologies where we believe an imaging solution
can swiftly impact clinical care.

## Key facts

- **NIH application ID:** 9899243
- **Project number:** 5R01EB027113-02
- **Recipient organization:** UNIVERSITY OF SOUTHERN CALIFORNIA
- **Principal Investigator:** Brian E. Applegate
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $672,471
- **Award type:** 5
- **Project period:** 2019-04-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9899243

## Citation

> US National Institutes of Health, RePORTER application 9899243, Optical imaging technologies to identify residual cholesteatoma and improve ossiculoplasty outcomes (5R01EB027113-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9899243. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*