Training to Modify Fixational Eye Movements for Optimizing Visual Performance in People With Central Vision Loss

October 31, 2024 updated by: Susana Chung, National Eye Institute (NEI)

Training to Modify Fixational Eye Movements for Optimizing Visual Performance

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
30

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Berkeley, California, United States, 94720
        • Herbert Wertheim School of Optometry & Vision Science, University of California Berkeley

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Microsaccade adaptation
A fixation target will be presented at the center of the display and participants will be asked to keep the target visible at all time. The investigators will measure participants' fixational eye movements continuously and when a microsaccade (small fast eye movements that occur during fixation of a visual target) is detected, the fixation target (a small dot) will jump to a different location, depending on whether the training is to adapt the microsaccades to have smaller or larger amplitudes. With trials, participants would automatically correct for the spatial errors and thus adapting their microsaccade amplitudes. Training consists of 5-6 sessions of training (about 1 hour each). These training sessions will be scheduled weekly if possible, but it is alright if the sessions are not exactly weekly.
Behavioral: Fixation training
Training (adapting) microsaccades during fixation

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Fixation stability
Time Frame: 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).
Eye positions measured while participants looked at a stationary fixation target for 10 seconds, quantified as the area that captures 68% of eye positions (unit: deg^2).
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 Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Visual acuity
Time Frame: 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).
Smallest letter that can be read on an acuity chart (Bailey-Lovie acuity chart). Unit of measurement will be in the logarithm of the minimum angle of resolution (logMAR).
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).
Contrast sensitivity
Time Frame: 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).
The faintest (lowest contrast) letter that can be read using the Mars Contrast Sensitivity Test. Unit of measurement will be in the logarithm of the contrast sensitivity ("log units").
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).
Reading performance: Maximum reading speed
Time Frame: 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).
Maximum reading speed (unit: words per minute) measured using the MNREAD Acuity Chart (MNREAD Acuity Chart is the name of the instrument that will be used).
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).
Reading performance: critical print size
Time Frame: 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).
The smallest print size (unit: logMAR) on the MNREAD Acuity Chart that still allow participants to read at their maximum reading speed.
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).
Orientation judgement accuracy: low spatial-frequency
Time Frame: 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).
Accuracy for judging the orientation (tilted to the left or right) of a low spatial-frequency grating. Unit of measurement will be in proportion-correct.
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).
Orientation judgement accuracy: high spatial-frequency
Time Frame: 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).
Accuracy for judging the orientation (tilted to the left or right) of a high spatial-frequency grating. Unit of measurement will be in proportion-correct.
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).
Characteristics of fixational eye movements: microsaccade rate
Time Frame: 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).
Fixational eye movements during the 10 seconds when participants are asked to fixate a target for fixation stability measurement (primary measurement) will be analyzed. The rate of microsaccades (fast eye movements during fixation) will be measured (unit: number per second).
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).
Characteristics of fixational eye movements: microsaccade amplitude
Time Frame: 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).
Fixational eye movements during the 10 seconds when participants are asked to fixate a target for fixation stability measurement (primary measurement) will be analyzed. The amplitude of microsaccades (fast eye movements during fixation) will be measured (unit: degrees).
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).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
National Eye Institute (NEI)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2025

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 29, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 31, 2024

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 1, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 1, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 31, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2024

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • R21EY030253 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

We will report summary results for the group. Some of the outcome measures are health related and we would like to protect the participants' privacy.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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