Recruiting

Observational Study

Sponsor:

Indiana University

Code:

NCT05888441

Conditions

Low Vision

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

Obstacle characteristics

Study Details

Brief summary:

Falls are common among people with vision impairment and can lead to devastating health consequences. Understanding the functions of vision and how the visual characteristics of obstacles in the walking path impact the gait of people with vision impairment is necessary to create strategies to prevent falls in this population. The purpose of this study is to determine how adults with vision impairment change their gait behavior when stepping over obstacles that vary in height and contrast to the ground. We will then determine the mechanisms of gaze behavior that correlate to the gait behavior.

Conditions

Low Vision

Study ID

NCT05888441

Start date

Apr 14, 2023

Status verified date

Nov, 2025

Completion date

Dec 31, 2028

Anticipated

Primary completion date

Dec 31, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Age 18 or over
  • Able to walk independently
  • Either have normal vision, or impaired vision.

  • Impaired vision is defined as binocular visual acuity of 20/25 or worse with or without a central scotoma; and/or binocular visual field that is restricted to an average of 100 degrees in diameter or less
  • Control subjects will have visual acuity of 20/40 or better.

Exclusion Criteria:

  • Not cleared by a medical provider for moderate physical activity
  • Self-report or have a history of: vestibular disorder or deafness
  • Medical history of any condition that affects the ability to walk for up to 2 hours with breaks, such as feeling dizzy or faint, chest pain, palpitations, pain or numbness in the legs, shortness of breath,
  • Cognitive limitations either by self-report or a score on the Mini Mental State Exam below 24 (out of 30)
  • Walking or gait abnormalities, such as those caused from an injury, surgery, severe arthritis, or neurological condition such as Parkinson's disease
  • Unable to walk without any walking aids such as a walker, cane, guide dog, or oxygen tank.
  • Does not speak English

Study Design

Enrollment

200 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Low Vision Group

At a single study visit, the group of low vision participants will be asked to perform a series of short walking trials. During each trial they will walk at a self-selected speed along a walkway (6 meters in length) that may or may not contain an obstacle to step over. The trials will be randomly varied with regard to an obstacle's presence, height, and contrast from the walkway surface. Repeated trials of each condition variation will be performed during the visit.

active comparator: Control Group

At a single study visit, the group of age-matched participants without low vision will be asked to perform a series of short walking trials. During each trial they will walk at a self-selected speed along a walkway (6 meters in length) that may or may not contain an obstacle to step over. The trials will be randomly varied with regard to an obstacle's presence, height, and contrast from the walkway surface. Repeated trials of each condition variation will be performed during the visit.

Interventions

Obstacle characteristics

In the walking trials, when an obstacle is present, the obstacle height and obstacle contrast level will be varied across the trial repetitions.

Each participant will be exposed to obstacles of two heights: the first will be 1 centimeter in height, and the second will be approximately 20% of the subject's leg length (ranging in physical height between 15 - 22 centimeters to cover a range of leg lengths in the population).

Obstacles (of both heights) will also be painted such that their measured luminance (or contrast) level against the floor luminance is varied. High contrast obstacles will have ≥80% Michelson contrast and low contrast obstacles will have ≤30% Michelson contrast.

Primary outcome measure

  • Vertical foot clearance, lead limb [ Time Frame: During a single intervention visit (Study Visit 2), up to 2-3 hours in duration. ]
  • Foot placement variability [ Time Frame: During a single intervention visit (Study Visit 2), up to 2-3 hours in duration. ]
  • Obstacle crossing speed [ Time Frame: During a single intervention visit (Study Visit 2), up to 2-3 hours in duration. ]
  • Gaze sequencing [ Time Frame: During a single intervention visit (Study Visit 2), up to 2-3 hours in duration. ]

Central Contacts and Locations

Central contacts

Kierstyn A Napier-Dovorany, OD

8128554426knapier@iu.edu

Locations

Indiana University

Recruiting

Bloomington, Indiana, United States, 47405

Contacts

Kierstyn A Napier-Dovorany, OD

812-855-4426knapier@iu.edu

More Information

Sponsor

Indiana University

Last update posted

Nov 13, 2025

Last verified

Nov, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Indiana University on 2025-11-13.