Real-time Acoustic Biofeedback for Enhancing Fixation Stability: A Proof-of-concept Study to Improve Ophthalmic Imaging Diagnostic Quality

NCT07529041 | Enrolling By Invitation

• 1 other identifier: 17/5/25
• Study Type: interventional
• Target: 22
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this Proof of Concept Feasibility Study is to improve the fixation stability in patients with fixation loss due to blindness or central vision loss using a patented acoustic real-time feedback device. The main questions it aims to answer are:

1. 1.Fixation guidance - can real-time acoustic biofeedback improve the fixation in healthy patients as well as patients with fixation loss?
2. 2.Optimization of fixation guidance - testing of different stimuli to optimize an acoustic training protocol.
3. 3.Optimization of imaging acquisition - testing improvement of both imaging quality and acquisition time using the acoustic feedback tool.

Conditions

Retinal Dystrophies; Geographic Atrophy; Blindness

Outcome Measures

Primary Outcomes (1)

• Fixation stability - change from baseline fixation stability recorded without acoustic fixation device compared to fixation stability recorded with acoustic fixation device

  In Phase A, we analyse the fixation stability as the distance from the target center (Median \[IQR\]), duration of fixation and time to achieve stable fixation (latency). We also use posthoc video analysis to generate the BCEA as a measure of fixation stability in each condition and each angle (0 and 15 degrees).

  Day 1

Secondary Outcomes (5)

• Change in time to achieve fixation over repeated trials

  Day 1

• Subjective exhaustion rating (Likert scale, 1-10)

  Day 1

• Difference in fixation stability (BCEA, time to fixate in ms) between blind and healthy participants across feedback conditions

  Day 1

• Correlation between pupil diameter change (mm) and fixation stability (BCEA)

  Day 1

• Comparison of fixation stability with clinical and imaging parameters

  Day 1

Study Arms (2)

Blind participants

EXPERIMENTAL

Blind participants receive auditory feedback via our acoustic fixation device in three conditions to assess effects on fixation.

Device: A device providing acoustic real-time biofeedback

Healthy participants

EXPERIMENTAL

Healthy participants receive the same auditory feedback via our acoustic fixation device in three conditions to assess effects on fixation.

Device: A device providing acoustic real-time biofeedback

Interventions

A device providing acoustic real-time biofeedback DEVICE

We use a camera and an eye tracking software, linked with our spatial-audio mapping tool. Participants receive real-time audio feedback on the location of their gaze. Negative feedback sounds are encoded to convey distance and direction of the deviation from the center. When the patients fixate on the target area, they receive a positive feedback sound.

Also known as: eyeFAST - eye Fixation by Acoustic Stabilization & Tracking

Blind participants; Healthy participants

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Healthy participants:
• minimum age of 18 years
• no neurological or ophthalmological disease
• ability to perceive auditory feedback
• normal vision
• consent to participate in study
• Patients:
• minimum age of 18 years
• existing ophthalmological diagnosis of fixation deficite or loss
• ability to perceive auditory feedback
• consent to participate in study

You may not qualify if:

• lack of ability to consent to participate in study
• reduced cooperation during examination or recording
• inability to perceive auditory feedback
• age below 18 years
• patients with nystagmus or inability to move eyes
• opacity of cornea or other ocular structures preventing successful eye tracking
• inability to communicate

Sponsors & Collaborators

• University Medical Center Goettingen: lead
• EKFZ Else Kroener Fresenius Center for Optogenetic Therapies: collaborator

Study Sites (1)

EKFZ Else Kroener Fresenius Center for Optogenetic Therapies, University Medical Center Goettingen

Göttingen, 37075, Germany

Location

MeSH Terms

Conditions

Retinal Dystrophies; Geographic Atrophy; Blindness

Condition Hierarchy (Ancestors)

Retinal Degeneration; Retinal Diseases; Eye Diseases; Macular Degeneration; Vision Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Dorothea S Laurence, MD

  University Medical Center Goettingen

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clincian Scientist, MD

Model Details: Participants are assigned to one of two groups (blind patients or healthy subjects). Each participant undergoes a single-session assessment in which multiple device conditions are tested within-subject. The study used a mixed-design with one between-subject factor (group: blind vs. healthy participants) and one within-subject factor (condition visual, auditory, combined). Phase A: proof of concept study (22 participants) Phase B: device optimization (11 blind participants of Phase A)

Study Record Dates

• First Submitted: March 24, 2026
• First Posted: April 14, 2026
• Study Start: August 27, 2025
• Primary Completion: April 15, 2026
• Study Completion: May 15, 2026
• Last Updated: April 14, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

DE (1)