A Monocentric Study Evaluating Pupillometry as an Objective Measurement for CI Fittings

Study Overview
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Brief Summary
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This trial is a monocentric, prospective and controlled study of the pupil response to detect hearing threshold and comfortable loudness of normal-hearing (NH) and CI-subjects.

Detailed Description
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The purpose of the clinical investigation is to explore the pupil dilation response of subjects with a cochlear implant and to provide proof of concept that it is possible to perform the adaptation of a cochlear implant using pupillometry. The population of this study is divided in 2 group: A control group with normal-hearing listeners. An Cl group with subjects with bilateral, severe-to-profound sensorineural hearing loss, with at least one cochlear implant for more than 6 months. Mainly used in audiology to evaluate listening effort, pupillometry is an objective measure that could also be used for fittings. Studies have shown that sound intensity influence pupil dilation. indeed, normal hearing and hearing aids subjects exhibit larger pupil responses with increasing intensity/loudness. The purpose of this study is to explore the pupil dilation response of cochlear implant subjects and to provide a proof of concept that we can perform cochlear implant fitting using pupillometry. Implanted subjects (Cl group) will undergo up to 3 visits: Visit 1 or V1(inclusion) on day 1, Visit 2 or V2 (Experiment 1-+2+3 or Experiment 1+2 or Experiment 3 )* up to 1 month after V1 Visit 3 or V3 (Experiment 1+2 or Experiment 3, optional)* up to 1 month after V2 *lt is up to investigator decision to conduct experiment 1+2 and experiment 3 the same day or in on independent visit (no matter in which order) Normal-hearing listeners (control group) will undergo up to 2 visits: Visit 1 or Va (inclusion) on day 1, Visit 2 or V2 (experiment) up to 1 month after V1

Official Title
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A Monocentric Study Evaluating Pupillometry as an Objective Measurement for Cochlear Implant (CI) Fittings

Conditions
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Hearing Loss, Sensorineural, Hearing Loss, Bilateral, Cochlear Hearing Loss, Hearing Loss, Cochlear

Intervention / Treatment
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* Other: Pupillometry (Eve-tracking measurements)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Both groups: Adult (≥ 18 years old) Fluent in French language Affiliation to social security Information and signature of a written consent prior to any study-specific procedure Control group (normal hearing in regards of age): • Normal hearing participants according to pure tone hearing levels defined for age and tested frequency (audiometry ISO 7029 and Wand & Puel, 2020 recommendations for hearing loss at the tested frequencies) CI group (cochlear implant subjects): Bilateral, severe-to-profound sensorineural hearing loss, with at least one cochlear implant system Using Oticon Medical Neuro Cochlear Implant System (NCIS) or Digisonic Cochlear Implant system (DCIS), unilateral or bilateral Duration of cochlear implant experience ≥ 6 months (period from cochlear implant activation to study enrolment) Pure Tone Audiometry must be strictly below 50 dBA, CI aided. Exclusion Criteria: Both groups, according to the best practices for pupillometry (Winn et al., 2018): Eye diseases: nystagmus, amblyopia, and macular degeneration Severe head injury or any history of significant neurological problems: These issues can affect gaze stability, congruence of eye movements, and pupil dilation Concomitant medication that can impact the parasympathetic autonomic nervous system Person under State Medical Assistance (AME for Aide medical d'état in French) Use of one of the following treatments: Trihexyphenidyl, Biperiden or Tropatepine (anticholinergics, commonly used in the treatment of Parkinson's disease) Person under legal protection (guardianship, curators, other, etc.) or under family authorization Unwillingness or inability to comply with all investigational requirements Additional cognitive, medical, or social handicaps that would prevent completion of all study requirements

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: A control group with normal hearing subjects versus a CI group with cochlear implanted subjects.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Control group (normal hearing in regards of age)<br>Normal hearing participants according to pure tone hearing levels defined for age and tested frequency (audiometry ISO 7029 and Wang & Puel, 2020 recommendations for hearing loss at the tested frequencies). Total of 32 subjects in this arm. | Other: Pupillometry (Eve-tracking measurements)<br>* Pupillometry measurements are carried out by a dedicated device (eye tracker), which includes cameras allowing the measurement of pupillary dilation. The subject stands in front of a screen and fixes a point in the center of the screen, the cameras placed on the screen allowing a measurement of the pupillary dilation in a non-invasive way. These eye-tracking measurements are performed simultaneously with an auditory task and allow to study the pupil's response to different stimuli.<br>|
| Experimental: CI group (cochlear implanted subjects)<br>Cochlear implanted subjects with bilateral, severe-to-profound sensorineural hearing loss, with at least one Oticon Medical cochlear implant system . Up to 40 subjects in this arm: 20 subjects will perform experiment 1 & 2 20 subjects will perform experiment 3 The subjects of the experiment 3 ore either those taken part to experiment 1 and 2, or subjects who only take port to the experiment 3 | Other: Pupillometry (Eve-tracking measurements)<br>* Pupillometry measurements are carried out by a dedicated device (eye tracker), which includes cameras allowing the measurement of pupillary dilation. The subject stands in front of a screen and fixes a point in the center of the screen, the cameras placed on the screen allowing a measurement of the pupillary dilation in a non-invasive way. These eye-tracking measurements are performed simultaneously with an auditory task and allow to study the pupil's response to different stimuli.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measurement of the pupil dilation response to a range of auditory stimuli (acoustic and electric). | Pupil dilation response for each intensity and frequency [Mean pupil dilatation in milimeters] | At Visit 2 (Month 1) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of the loudness perception of the subjects regarding the different auditory stimuli (acoustic and electric) to correlate the results to the pupil dilation response. | Loudness score corresponding to each pupil dilation response. [Using Oticon Medical Loudness scale: scale from 0 to 10 following the ISO 16832. 0 (zero) corresponding to inaudible level and 10 to extremely loud (intolerable) sounds.] | At Visit 2 (Month 1) and Visit 3 (Month 2)* [* if done] | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cochlear Implant system