N/A N=26 Basic Science

Environmental Localization Mapping and Guidance for Visual Prosthesis Users

Retinitis Pigmentosa · Visual Impairment · Visual Prosthesis

Bottom Line

View on ClinicalTrials.gov: NCT04359108 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Mar 2025

Primary outcome: Primary: Duration of Time to Complete Navigational Tasks as Assessed by the Mean Duration of Travel in Seconds Normalized by the Nominal Path Distance in Meters — 14.54; 14.09; 10.46; 14.60 seconds/meter — p=0.02

Study Design & Population

Study type: Interventional
Phase: N/A
Interventions: Navigation system mode: Argus Vision (Device); Navigation system mode: Depth Vision (Device); Navigation system mode: Depth Vision with Haptic / Audio (Device); Navigation system mode: Haptic / Audio (Device); Navigation system mode: High Field-of-View Depth Vision (Device); Distance test vision mode: Low Resolution / Low Field-of-View (Device); Distance test vision mode: Low Resolution / High Field-of-View (Device); Distance test vision mode: High Resolution / Low Field-of-View (Device); Distance test vision mode: High Resolution / High Field-of-View (Device)
Age: Adult, Older Adult · 18+ yrs
Sex: All
Sponsor: Johns Hopkins University
Primary completion: Sep 2024

Outcome Measures

Outcome	Result	p-value
PRIMARY Duration of Time to Complete Navigational Tasks as Assessed by the Mean Duration of Travel in Seconds Normalized by the Nominal Path Distance in Meters	14.54; 14.09; 10.46; 14.60; 9.38; 14.05	0.02 sig
PRIMARY Distance Traversed to Complete Navigational Tasks as Assessed by the Mean Distance Traveled in Meters Normalized by the Nominal Path Distance in Meters	1.598; 1.543; 1.305; 1.427; 1.227; 1.537	0.30
PRIMARY Obstacle Avoidance While Completing Navigational Tasks as Assessed by the Mean Number of Contacts With Obstacles Normalized by the Nominal Path Distance in Meters	0.737; 0.523; 0.224; 0.465; 0.201; 0.175	<0.001 sig
PRIMARY Success in Completing Navigational Tasks as Assessed by the Mean Percentage of Trials Where Participants Successfully Reached the Intended Destination	50.0; 0; 65.7; 50; 97.5; 100	<0.001 sig
PRIMARY Accuracy of Relative Distance Judgments as Assessed by the Percentage of Correct Responses	62; 83; 72.2; NA; 67.8; NA	0.023 sig

Summary

This study is driven by the hypothesis that independent navigation by blind users of visual prosthetic devices can be greatly aided by use of an autonomous navigational aid that provides information about the environment and guidance for navigation through multimodal sensory cues. For this study, the investigators developed a navigation system that uses on-board sensing to map the user's environment and compute navigable paths to desired destinations in real-time. Information regarding obstacles and directional guidance is communicated to the user via a combination of sensory modalities including limited vision (through the user's visual prosthesis), haptic, and audio cues. This study evaluates how effectively this navigational aid improves prosthetic vision users' ability to perform navigational tasks. The participants for this study include both retinal prosthesis users of the Argus II Retinal Prosthesis System (Argus II) and normally sighted individuals who use a virtual reality headset to simulate the limited vision of the Argus II system.

Eligibility Criteria

Criteria for inclusion of normally sighted individuals:

Subject speaks English;
Subjects must be an adult (at least 18 years of age);
Subject has the cognitive and communication ability to participate in the study (i.e., follow spoken directions, perform tests, and give feedback);
Subject is willing to conduct psychophysics testing up to 4-6 hours per day of testing on 3-5 consecutive days;
Subject has visual acuity of 20/40 or better (corrected);
Subject is capable of understanding participant information materials and giving written informed consent.
Subject is able to walk unassisted

Criteria for inclusion of Argus II users:

The inclusion criteria for the study are the following:

Subject is at least 25 years of age;
Subject has been implanted with the Argus II system;
Subject's eye has healed from surgery and the surgeon has cleared the subject for programming;
Subject has the cognitive and communication ability to participate in the study (i.e., follow spoken directions, perform tests, and give feedback);
Subject is willing to conduct psychophysics testing up to 4-6 hours per day of testing on 3-5 consecutive days;
Subject is capable of understanding patient information materials and giving written informed consent;
Subject is able to walk unassisted.

Exclusion criteria for all subjects is the following:

Subject is unwilling or unable to travel to testing facility for at least 3 days of testing within a one-week timeframe;
Subject does not speak English;
Subject has language or hearing impairment.

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT04359108). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.