Eye Movement Rehabilitation in Low Vision Patients
1 other identifier
observational
106
1 country
2
Brief Summary
Approximately 217 million people worldwide currently suffer from low vision, which impacts a broad range of activities of daily living and is associated with depression and increased mortality. Over half of the patients presenting for low vision services have eye disease that affects the fovea and surrounding macula and leads to central vision loss (CVL). People with CVL are forced to use eccentric vision as a substitute for their impaired fovea, however eye movement control and visual function is impaired with eccentric vision. Recent evidence and preliminary results from the investigators show that rehabilitation methods can help improve oculomotor control and this can lead to improved functional outcomes. The investigators have developed new feedback-based training methods that aim to improve eccentric vision use by patients with CVL. In a series of studies, the investigators examine rehabilitation of fixation control, smooth pursuit eye movements that track moving objects and saccadic eye movements that abruptly change the point of regard. The investigators examine how visual feedback, scotoma awareness methods and hand-eye coordination can improve eccentric vision use. Improvements in oculomotor control are quantified with eye tracking methods and associated changes in visual function are quantified with acuity, contrast sensitivity and reading performance. The proposed research therefore develops and translates state-of-the-art methods in basic science to clinical applications. Accomplishing the proposed aims will provide new and improved methods for rehabilitation strategies for visual impairment. The ultimate goal of this proposal is to maximize the residual visual function of people with low vision and to help them to live independently, thereby improving quality of life and minimizing the economic and social burden of visual impairment.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for all trials
Started Sep 2020
Typical duration for all trials
2 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
September 4, 2020
CompletedFirst Submitted
Initial submission to the registry
September 16, 2020
CompletedFirst Posted
Study publicly available on registry
June 18, 2021
CompletedPrimary Completion
Last participant's last visit for primary outcome
May 1, 2023
CompletedStudy Completion
Last participant's last visit for all outcomes
January 31, 2024
CompletedMay 6, 2023
May 1, 2023
2.7 years
September 16, 2020
May 2, 2023
Conditions
Outcome Measures
Primary Outcomes (7)
Change in Visual Acuity
The smallest band-pass filtered letter that can be identified at 100% contrast
Before, immediately after and 2 weeks after behavioral intervention
Change in Contrast Sensitivity
The lowest contrast band-pass filtered letter that can be identified as a function of spatial frequency
Before, immediately after and 2 weeks after behavioral intervention
Change in Fixation control
Bivariate Contour Ellipse Area of Fixation (degrees of visual angle)
Before, immediately after and 2 weeks after behavioral intervention
Change in Saccadic Eye Movement Latency
Latency (msec) after stimulus displacement before onset of saccadic eye movement
Before, immediately after and 2 weeks after behavioral intervention
Change in Saccadic Eye Movement Amplitude
Amplitude (degrees per sec) of eye movements between fixation targets
Before, immediately after and 2 weeks after behavioral intervention
Change in Smooth Pursuit Eye Movement Latency
Latency (msec) after stimulus movement before onset of pursuit eye movement
Before, immediately after and 2 weeks after behavioral intervention
Change in Smooth Pursuit Eye Movement Gain
Gain (ratio of eye movement speed divided by stimulus speed) during stimulus movement
Before, immediately after and 2 weeks after behavioral intervention
Study Arms (5)
Fixation PRL
Visual feedback will be provided at the the preferred retinal locus (PRL) to train subjects to attend to a fixation location. Feedback consists of a gaze-contingent ring whose size varies depending on task performance. Training consists of 5 blocks of up to 50 trials, each block lasting approximately 10 minutes. Acuity and contrast sensitivity will be assessed at the PRL with forced choice psychophysical letter identification tasks. Gaze behavior will be measured with an eye tracker.
Smooth Pursuit PRL
Visual feedback will be provided to train subjects to attend to a PRL for smooth pursuit eye movements. Feedback consists of a gaze-contingent ring whose size varies depending on the subject's ability to center the ring on a drifting target. Training consists of 5 blocks of up to 50 trials, each block lasting approximately 10 minutes. Acuity and contrast sensitivity will be assessed at the PRL with forced choice psychophysical letter identification tasks. Smooth pursuit tracking behavior will be measured with an eye tracker.
Saccade PRL
Visual feedback will be provided to train subjects to attend to a PRL for saccadic eye movements. Feedback consists of a gaze-contingent ring whose size varies depending on the subject's ability to center the ring on an abruptly shifting dot. Training consists of 5 blocks of up to 50 trials, each block lasting approximately 10 minutes. Acuity and contrast sensitivity will be assessed at the PRL with forced choice psychophysical letter identification tasks. Saccadic eye movement behavior will be measured with an eye tracker.
Scotoma Awareness PRL
Subjects are often unaware of their scotomas because they are filled in with the surrounding background texture. The investigators will exploit this filling in to increase awareness of the scotoma by surrounding the scotoma with a visible disk that will be perceptually completed across the scotoma, rendering the scotoma visible. In a randomized within-subjects design, Acuity and contrast sensitivity will be assessed with and without a Scotoma Awareness Disk at a Fixation, Smooth Pursuit and Saccade PRL with forced choice psychophysical letter identification tasks. Oculomotor behavior will be measured with an eye tracker.
Meta-Guidance PRL
Oculomotor control can be promoted in the location around our hands. The investigators will exploit this meta-guidance advantage by asking subjects to move their hand and their PRL to an on-screen target. In a randomized within-subjects design, Acuity and contrast sensitivity will be assessed with and without a Hand Movement at a Fixation, Smooth Pursuit and Saccade PRL with forced choice psychophysical letter identification tasks. Oculomotor behavior will be measured with an eye tracker.
Interventions
Gaze-contingent visual feedback
Eligibility Criteria
Human subjects with bilateral central vision loss
You may qualify if:
- over 14 year of age
- logMAR Acuity 0.5-1.0
- Bi-lateral foveal scotomas \< 7 °radius
- Mini Mental State questionnaire ≥ 29
- no history of concurrent peripheral vision loss
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Northeastern Universitylead
- New England College of Optometrycollaborator
- National Eye Institute (NEI)collaborator
- Lighthouse Guildcollaborator
Study Sites (2)
NECO Center for Eye Care
Boston, Massachusetts, 02215, United States
Lighthouse Guild
New York, New York, 10023, United States
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Peter J Bex, PhD
Northeastern University
Central Study Contacts
Study Design
- Study Type
- observational
- Observational Model
- COHORT
- Time Perspective
- PROSPECTIVE
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
September 16, 2020
First Posted
June 18, 2021
Study Start
September 4, 2020
Primary Completion
May 1, 2023
Study Completion
January 31, 2024
Last Updated
May 6, 2023
Record last verified: 2023-05
Data Sharing
- IPD Sharing
- Will not share
De-identified data will be made available after publication of study outcomes via the Open Science Foundation data repository