Stochastic Resonance Applied to Amblyopia Training and the Plasticity of Brain

Sponsor

National Cheng-Kung University Hospital (Other)

Overall Status

Completed

CT.gov ID

NCT04213066

Collaborator

Chang Gung Memorial Hospital (Other)

Enrollment

Arms

30.6

Actual Duration (Months)

Study Details

Study Description

Brief Summary

The prevalence of Taiwan's population with amblyopia is 2-5%. Amblyopia affects the daily life and learning ability. The human visual system can be developed normally with exposure of clear images on the retina, which often drive the development and projection of optic nerves progressively. In general, the visual acuity progresses gradually with age. A normal vision is relatively mature until 8 years old. Several types of amblyopia (strabismic amblyopia, refractive amblyopia, and deprivation amblyopia) are identified. The refractive amblyopia and deprivation amblyopia must be corrected by wearing glasses or surgeries. Otherwise, amblyopia is often corrected by occlusion of the dominant eye or amblyopia training. The Cambridge Stimulator (CAM) with rotating grating is commonly used in clinic in Taiwan. The principle of the CAM allows subjects to draw pictures on the plate in coincidence with occlusion of the dominant eye. The parents have to go with their children to a hospital weekly. The CAM training is a stereotyped visuomotor behavior, which usually causes fatigue and uninteresting results for children.

Recently, some computer games have been incorporated with CAM training. However, their clinical impact on amblyopia is largely unknown. Moreover, most of studies don't have long-term tracking, and they only use limited assessments. In this project, a home-based training would be built for children with amblyopia. A CAM training with a hierarchical structure with story-based organization would be implemented in the tablet. It will save time for children and parents for traffic between the home and hospital. The CAM training with organized structure would increase acceptability and create subjects' motivation for long-term training. In addition, a stochastic resonance theory would be incorporated with the CAM training to potentiate the learning curve of a visuomotor skill in young children. Five systematic assessments, including visual acuity, grating acuity, contrast sensitivity, and 2 measurements of visual evoked potentials (VEPs), would be used. The investigators hypothesized that the rotating grating stimulation and stochastic resonance stimulation groups showed significant enhancement of the visual functions compared with the control group and performance of the VEPs toward better eye through the home-based training apparatus.

Condition or Disease	Intervention/Treatment	Phase
Amblyopia Amblyopia, Anisometropic	Device: Portable tablet	N/A

Study Design

Study Type:

Interventional

Actual Enrollment :

51 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Care Provider, Investigator)

Primary Purpose:

Treatment

Official Title:

Stochastic Resonance Applied to Amblyopia Training and the Plasticity of Brain

Actual Study Start Date :

Jul 15, 2013

Actual Primary Completion Date :

Jan 31, 2016

Actual Study Completion Date :

Jan 31, 2016

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Control group This group received eye-hand practice for drawing pictures.	Device: Portable tablet Each training session was limited to 15 minutes a day, 5 days a week. The entire training period was 6 months.
Experimental: Grating group This group received eye-hand practice for drawing pictures with rotating grating stimuli of various spatial frequencies.	Device: Portable tablet Each training session was limited to 15 minutes a day, 5 days a week. The entire training period was 6 months.
Experimental: Random dot group This group received eye-hand practice for drawing pictures with rotating grating stimuli of various spatial frequencies constructed by random dots of stochastic resonance.	Device: Portable tablet Each training session was limited to 15 minutes a day, 5 days a week. The entire training period was 6 months.

Arm

Intervention/Treatment

Active Comparator: Control group

This group received eye-hand practice for drawing pictures.

Device: Portable tablet

Each training session was limited to 15 minutes a day, 5 days a week. The entire training period was 6 months.

Experimental: Grating group

This group received eye-hand practice for drawing pictures with rotating grating stimuli of various spatial frequencies.

Device: Portable tablet

Each training session was limited to 15 minutes a day, 5 days a week. The entire training period was 6 months.

Experimental: Random dot group

This group received eye-hand practice for drawing pictures with rotating grating stimuli of various spatial frequencies constructed by random dots of stochastic resonance.

Device: Portable tablet

Each training session was limited to 15 minutes a day, 5 days a week. The entire training period was 6 months.

Outcome Measures

Primary Outcome Measures

Visual acuity (VA) [Change from Baseline VA at 1, 2, 3 and 6 months]
Landolt C chart was used.
Grating acuity (GA) [Change from Baseline GA at 1, 2, 3 and 6 months]
Horizontal or vertical square-wave grating stimuli were used.
Contrast sensitivity (CS) [Change from Baseline CS at 1, 2, 3 and 6 months]
Circular-shape horizontal square-wave grating stimuli were used.
Visual evoked potential (VEP) [Change from Baseline VEP at 1, 2, 3 and 6 months]
Transient VEP and Steady state VEP of the Cortical EEG were recorded.

Secondary Outcome Measures

Total practice duration [Throughout 6 months]
Practice duration was recorded in the tablet.

Eligibility Criteria

Criteria

Ages Eligible for Study:

4 Years to 8 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Participants were 4-8 years old.
Participant had binocular or monocular best-corrected visual acuity (BCVA) of ≤0.8, or they exhibited binocular BCVA difference of ≥0.2.
Participant had the wearing of optimal spectacle correction.