Clinical trial NCT06670989: Training to Modify Fixational Eye Movements for Optimizing Visual Performance in People With Central Vision Loss
Official title: Training to Modify Fixational Eye Movements for Optimizing Visual Performance
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Central Vision Loss From Macular Diseases
Keywords: fixational eye movements
microsaccades
saccade adaptation
fixation training
Lead sponsor: National Eye Institute (NEI)
Sponsor class: NIH
First posted: 2024-11-01
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief summary: People with central vision loss almost all have exaggerated fixational eye movements when compared with people with normal vision (e.g. larger amplitudes of microsaccades and ocular drifts). Central vision loss primarily results from eye diseases or disorders that affect the macular region of the retina, such as age-related macular degeneration (AMD) and Stargardt disease. The clinical wisdom is that exaggerated fixational eye movements are detrimental to vision. This forms the basis of the increasing number of clinical trials that use fixation stability (variability of eye positions during fixation) as an outcome measure to evaluate the effectiveness of interventions on age-related macular degeneration or other retinal diseases, despite the lack of causal evidence supporting or refuting a relationship between fixational eye movements and functional vision. If excessive fixational eye movements are indeed detrimental to vision for people with central vision loss, can we reduce the amount of their fixational eye movements, thus improve their fixation stability? And if so, does that lead to improved functional vision? The goal of this study is to examine the hypothesis that retinal image motion due to abnormal fixational eye movements can be modified through fixation training, with accompanied improvements in functional vision as a result.


Eligibility criteria: Inclusion Criteria:

Participants with normal vision:

* age 18 or above
* best corrected visual acuity of at least 20/20 in each eye
* cataracts, if present, must be minimal (grade 1 or below according to the Lens Opacity Classification System)
* normal contrast sensitivity for their ages
* stereoacuity at least 40 seconds of arc
* no history or signs of any retinal diseases

Participants with macular disorders:

* age 18 or above
* macular disorder present in both eyes
* presence of at least one scotoma within the central 5 degrees of the visual field and with best corrected visual acuity of at least 20/400 in the better-seeing eye
* no foveal island of vision left (i.e. absolute scotoma must include the foveal area)
* cataracts, if present, must be grade 2 or lower according to the Lens Opacity Classification System II

Exclusion Criteria:

Participants with normal vision:

* younger than 18 years of age
* best corrected visual acuity worse than 20/20 in each eye
* cataracts worse than grade 1 according to the Lens Opacity Classification System II
* abnormal contrast sensitivity for their ages
* stereoacuity worse than 40 seconds of arc
* history or signs of any retinal diseases

Participants with macular disorders:

* younger than 18 years of age
* macular disorder absent in at least one eye
* no scotoma within the central 5 degrees of the visual field in the better-seeing eye
* best corrected visual acuity of worse than 20/400 in the better-seeing eye
* foveal island of vision
* cataracts worse than grade 2 according to the Lens Opacity Classification System II

Primary outcomes:
measure: Fixation stability
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
Secondary outcomes:
measure: Visual acuity
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Contrast sensitivity
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Reading performance: Maximum reading speed
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Reading performance: critical print size
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Orientation judgement accuracy: low spatial-frequency
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Orientation judgement accuracy: high spatial-frequency
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Characteristics of fixational eye movements: microsaccade rate
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
measure: Characteristics of fixational eye movements: microsaccade amplitude
timeFrame: Data will be collected immediately before (within 1 hour) the first training session and immediately after (within 1 hour) the last training session. Data will be reported when analysis is completed for all participants (target date: by June 2025).
Other outcomes:
Locations:
city: Berkeley
country: United States
facility: Herbert Wertheim School of Optometry & Vision Science, University of California Berkeley
state: California
Study officials:
References: