Obstacle Negotiation Training for Low Vision

Overseen By Kierstyn A Napier-Dovorany, OD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Indiana University

Disqualifiers: Vestibular disorder, Deafness, Cognitive limitations, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

200 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how individuals with vision impairment adjust their walking when encountering obstacles of varying height and contrast. The research will help develop strategies to prevent falls, which are common among people with vision issues. Participants will walk along a path with different obstacles to observe changes in their gait and gaze. Individuals who can walk independently and have vision impairment, such as difficulty seeing clearly or a limited field of view, might be suitable for this study. As an unphased trial, this study offers a unique opportunity to contribute to important research that could enhance safety and mobility for those with vision impairments.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that this obstacle negotiation training is safe for people with low vision?

Research shows that people with vision loss can adjust their movements and gaze to safely avoid obstacles, even when not in a hurry. This suggests that the obstacle training in the study is generally safe. Studies have found that adding obstacles can slow walking speed, but they have not reported any serious safety issues.

This trial does not test a new drug or treatment. Instead, it examines how people walk, so no side effects like those in medication trials are expected. Participants will step over obstacles of different heights and colors, a normal and familiar activity. Therefore, the risk of harm is low. Scientific evidence supports this as a safe way to study how people with vision impairment navigate their environment. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Obstacle Negotiation Training for people with low vision because it focuses on improving real-world mobility challenges rather than relying solely on visual aids or surgery. Unlike standard treatments that often center around enhancing visual clarity with glasses, contact lenses, or magnification devices, this approach uses practical training to help individuals navigate obstacles they encounter daily. By varying the presence, height, and contrast of obstacles, the training aims to enhance adaptability and confidence in moving through complex environments, which can be a game-changer for those with low vision.

What evidence suggests that obstacle negotiation training is effective for preventing falls in people with low vision?

Research has shown that people with vision loss can change how they walk and look at things to safely avoid obstacles when not rushed. They can adjust their movements and focus to prevent tripping or falling. This trial will compare a Low Vision Group with a Control Group to study these adaptations. Studies also indicate that successfully navigating obstacles involves using both sight and body movements. Even with vision problems, people can adapt to different obstacle heights and visibility, although taller obstacles might pose more difficulty. Overall, these findings support the idea that understanding how obstacles affect movement can help develop strategies to prevent falls in people with low vision. ^{4 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for adults over 18 who can walk on their own. It's for those with normal vision or impaired vision, defined as having a visual acuity of 20/25 or worse, possibly with central scotoma, or a restricted field of view. People not allowed include those advised against moderate exercise by doctors, have vestibular disorders or deafness, conditions affecting long walks, cognitive issues (scoring below 24 out of 30 on the Mini Mental State Exam), gait abnormalities from injuries or diseases like Parkinson's, and non-English speakers.

Inclusion Criteria

I can walk on my own without help.

You can see normally, or you have impaired vision, meaning your eyesight is 20/25 or worse with or without a central blind spot, and your field of vision is limited to an average of 100 degrees or less.

People in the control group need to have good eyesight, with a visual acuity of 20/40 or better.

Exclusion Criteria

I have a history of balance issues or deafness.

I can walk for up to 2 hours with breaks without feeling dizzy, chest pain, or shortness of breath.

I am not cleared for moderate exercise by a doctor.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Intervention

Participants perform a series of short walking trials with obstacles of varying height and contrast

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the intervention

2-4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Obstacle characteristics

Trial Overview The study tests how adults with vision impairment adjust their walking when they encounter obstacles that differ in height and contrast to the ground. The goal is to understand how these individuals use their gaze and change their gait to navigate safely and potentially reduce fall risks.

How Is the Trial Designed?

Group I: Low Vision Group Experimental Treatment 1 Intervention

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.

Group II: Control Group Active Control 1 Intervention

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.

Who Is Running the Clinical Trial?

Indiana University

Lead Sponsor

Trials

1,063

Recruited

1,182,000+

Published Research Related to This Trial

Participants with low vision (LV) showed significant mobility challenges when their visual field was less than 1.2 steradians (sr), indicating that practitioners should monitor mobility difficulties at this threshold.

Visual fields constricted to between 0.23 and 0.63 sr (31 to 52° diameter) signal a need for mobility rehabilitation, while critical mobility issues arise when the visual field is reduced to 0.05 sr (15° diameter).

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Visual field size criteria for mobility rehabilitation referral. Lovie-Kitchin, JE., Soong, GP., Hassan, SE., et al.[2022]

The LOVIT II trial is a multicenter randomized controlled trial involving 330 patients with macular disease, aiming to compare the effectiveness of low vision rehabilitation (LVR) with basic low vision (LV) services.

Preliminary results show that LVR, which includes therapy sessions to teach effective use of vision aids, may lead to better improvements in visual reading ability compared to basic LV, where devices are simply dispensed without additional training.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

VA LOVIT II: a protocol to compare low vision rehabilitation and basic low vision. Stelmack, JA., Tang, XC., Reda, DJ., et al.[2015]

This systematic review identified a wide variety of outcome measures used to assess orientation and mobility (O&M) performance in adults with vision impairment, highlighting the complexity of measuring O&M due to the diverse aspects such as efficiency, obstacle avoidance, and social interaction.

Nearly half of the identified outcome measures demonstrated strong validity, reliability, and feasibility, suggesting they can be effectively implemented in clinical practice to provide a comprehensive assessment of O&M abilities in individuals with low vision or blindness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Orientation and mobility outcome measures. Chang, KJ., Dillon, LL., Deverell, L., et al.[2021]

Training individuals with low vision using virtual reality can effectively teach them safe street crossing skills, as demonstrated by a study involving 12 participants who improved their timing for crossing streets after training.

Both virtual and real street training resulted in significant safety improvements, with 90% of participants' 'GO' calls occurring in the safer early half of the pedestrian phase after training, indicating that virtual reality can be a viable alternative to traditional training methods.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Individuals with severely impaired vision can learn useful orientation and mobility skills in virtual streets and can use them to improve real street safety. Bowman, EL., Liu, L.[2022]

A wearable device that projects a laser line onto curbs significantly enhances curb recognition for individuals with visual impairments, improving accuracy from 33% to 95% in identifying low-contrast curbs at a distance of five feet.

The effectiveness of the laser line as a visual cue is highly dependent on its angle relative to the user's walking path, indicating that proper alignment is crucial for maximizing safety and mobility for people with visual impairments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Structured Laser Light Improves Tripping Hazard Recognition for People with Visual Impairments. Stahl, M., Peli, E.[2021]

The NEI VFQ-25 questionnaire effectively measures changes in visual abilities after low-vision rehabilitation in veterans, with significant improvements noted in both the Blind Rehabilitation Center and Visual Impairment Center programs.

After rehabilitation, certain tasks like reading ordinary and small print became easier for veterans, indicating that low-vision aids and training contributed to improved functional abilities, although only 7 out of 34 items on the questionnaire showed sensitivity to these changes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Measuring low-vision rehabilitation outcomes with the NEI VFQ-25. Stelmack, JA., Stelmack, TR., Massof, RW.[2022]

The study developed 'residual vision glasses' (RVGs) that help visually impaired individuals detect obstacles by presenting distance information through brightness, leading to improved mobility performance, especially for those with the most severe impairments.

While participants were able to navigate obstacle courses using the RVGs, they experienced slower walking speeds and increased hesitations, indicating that while the technology shows promise, further research is needed to address these challenges.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Improving Mobility Performance in Low Vision With a Distance-Based Representation of the Visual Scene. van Rheede, JJ., Wilson, IR., Qian, RI., et al.[2022]

The Bristol Mobility Aid (BMA) did not improve mobility performance for visually impaired individuals, as evidenced by reduced preferred walking speeds and increased errors during navigation in an indoor course.

Both low-vision and sighted subjects experienced challenges when using the BMA, indicating that modifications are needed to enhance its effectiveness as a mobility aid.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mobility performance of low-vision adults using an electronic mobility aid. Jones, T., Troscianko, T.[2015]

A study involving 316 low-vision patients and 38 clinicians found that clinicians' predictions of the success of low-vision rehabilitation (LVR) did not correlate with the actual self-reported outcomes of patients, indicating a disconnect between clinician expectations and patient experiences.

Clinicians' predictions were influenced by patients' cognitive functioning and a combination of visual acuity and functional ability, but these predictions were not reliable, as they showed no better agreement with patient outcomes than chance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of clinician-predicted to measured low vision outcomes. Chan, TL., Goldstein, JE., Massof, RW.[2021]

In a study with 48 normally sighted participants using acuity-reducing goggles, it was found that the visibility of ramps and steps is significantly affected by viewing distance, with performance declining at larger distances but improving at closer ranges.

Interestingly, the study revealed that steps going up were more visible than steps going down, highlighting the importance of edge contours and height cues in enhancing visual accessibility for individuals with low vision.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Visual accessibility of ramps and steps. Legge, GE., Yu, D., Kallie, CS., et al.[2021]

Visually impaired individuals can learn to operate mobility scooters effectively, demonstrating sufficient driving skills despite their visual challenges, as shown in a study involving 48 visually impaired participants and 37 sighted controls.

Participants with visual field defects and low visual acuity faced more difficulties, particularly with skills like reverse driving and stopping, indicating that tailored training and individual assessments are essential for improving their mobility scooter driving abilities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mobility scooter driving ability in visually impaired individuals. Cordes, C., Heutink, J., Brookhuis, KA., et al.[2018]

A standardized indoor course was developed to effectively evaluate obstacle avoidance in individuals with ultralow vision, involving 36 blind participants and 6 sighted controls across multiple trials.

The course proved to be a feasible and cost-effective method for testing mobility function, showing significant differences in performance metrics like percent error and preferred walking speed across different course iterations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A standardized obstacle course for assessment of visual function in ultra low vision and artificial vision. Nau, AC., Pintar, C., Fisher, C., et al.[2021]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8434341/

A Preliminary Investigation of the Effects of Obstacle ... No significant differences in gait variability were observed after negotiating an obstacle, regardless of turning or not.

2. nature.com nature.com/articles/s41598-019-51926-y

The effects of temporal pressure on obstacle negotiation ... Individuals with vision loss adapt their locomotion and gaze behaviour to safely negotiate objects in temporally unconstrained situations.

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6139439/

The quality of visual information about the lower extremities ... Locomotor skills such as obstacle negotiation depend on the integration of visual information about the body and the environment with ongoing motor commands.

4. karger.com karger.com/ger/article/66/2/187/148354/Successful-Negotiation-of-Anticipated-and

Successful Negotiation of Anticipated and Unanticipated ... The results regarding the effects of obstacle height were unexpected. We hypothesized that taller obstacles would lower the success rates, ...

5. sciencedirect.com sciencedirect.com/science/article/pii/S0891422224001859

Obstacle negotiation while dual-tasking in children with ... This paper assessed locomotor obstacle negotiation under dual-task conditions, a common scenario that has safety implications for developing children.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11321504/

Visuospatial cognition predicts performance on an obstructed ... The results demonstrate that adding the obstructed vision board significantly slowed walking speed by an average of 0.26 m/s and increased the number of ...

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6817899/

The effects of temporal pressure on obstacle negotiation and ... Individuals with vision loss adapt their locomotion and gaze behaviour to safely negotiate objects in temporally unconstrained situations.

8. bmchealthservres.biomedcentral.com bmchealthservres.biomedcentral.com/articles/10.1186/1472-6963-9-153

Effects and feasibility of a standardised orientation and ... This paper presents the design of a randomised controlled trial aimed to evaluate this standardised O&M-training in using the identification cane in older ...

9. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0966636212000598

Visual exproprioceptive information is used in an online ... The quality of visual information about the lower extremities influences visuomotor coordination during virtual obstacle negotiation. 2018, Journal of ...