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Optical Correction and Visual Functions of Adults With Amblyopia (SPECTRA)

Primary Purpose

Amblyopia

Status
Recruiting
Phase
Not Applicable
Locations
Hong Kong
Study Type
Interventional
Intervention
Spectacles
Sponsored by
Centre for Eye and Vision Research
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Amblyopia focused on measuring Amblyopia, Binocular vision, Suppression, Plasticity, Optical correction

Eligibility Criteria

18 Years - 39 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria:

  • 18-39 (inclusive) years of age
  • Anisometropic amblyopia (difference of ≥0.50D spherical equivalent or ≥1.50D astigmatism between eyes) or mixed mechanism amblyopia (strabismus and anisometropia)
  • Best corrected visual acuity (BCVA) in the amblyopic eye of 0.3 logMAR to 1.0 logMAR (inclusive)
  • BCVA in the non-amblyopic eye of 0.1 logMAR or better, and an interocular VA difference of 2 logMAR lines or more
  • Difference of 1.00D or more between current refractive correction and study prescription
  • Good general health

Exclusion Criteria:

  • Other pathological ocular anomalies known to cause reduced visual acuity
  • Presbyopia (based on amplitude of accommodation)
  • Inability to tolerate full refractive correction in spectacles (e.g., due to aniseikonia)
  • Contraindication to cycloplegic eye drops (only when necessary for assessing residual refractive error)
  • Currently under amblyopia treatment/therapy
  • Inability to comprehend test instructions and/or provide consent
  • Eccentric fixation and/or abnormal retinal correspondence
  • >-6.00DS of myopia in either eye with spectacles
  • Bilateral amblyopia
  • Presence of amblyopia that is not due to strabismus and/or anisometropia
  • Presence of (current or previous) attention disorder, learning disability, psychiatric, visual, or neurological disorders

Sites / Locations

  • Centre for Eye and Vision Research LimitedRecruiting

Arms of the Study

Arm 1

Arm Type

Experimental

Arm Label

Optical correction

Arm Description

Prescription of spectacles for full-time wear to correct refractive error

Outcomes

Primary Outcome Measures

Best corrected visual acuity of the amblyopic eye pre-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Best corrected visual acuity of the amblyopic eye post-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.

Secondary Outcome Measures

Best corrected visual acuity of the amblyopic eye during intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Fellow eye distance visual acuity pre-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Fellow eye distance visual acuity post-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Fellow eye distance visual acuity during-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Binocular distance visual acuity pre-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Binocular distance visual acuity post-intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Binocular distance visual acuity during intervention
The size of the smallest line of letters read accurately on an ETDRS chart.
Near visual acuity of amblyopic eye pre-intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near visual acuity of amblyopic eye post-intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near visual acuity of amblyopic eye during intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near visual acuity of fellow eye pre-intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near visual acuity of fellow eye post-intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near visual acuity of fellow eye during intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near binocular visual acuity pre-intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near binocular visual acuity post-intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Near binocular visual acuity during intervention
The size of the smallest line of letters read accurately on a near ETDRS chart.
Amblyopic eye contrast sensitivity pre-intervention
Computer-based measurement of contrast sensitivity
Amblyopic eye contrast sensitivity post-intervention
Computer-based measurement of contrast sensitivity
Amblyopic eye contrast sensitivity during intervention
Computer-based measurement of contrast sensitivity
Stereopsis pre-intervention
Smallest disparity on the Randot preschool test reported accurately.
Stereopsis post-intervention
Smallest disparity on the Randot preschool test reported accurately.
Stereopsis during intervention
Smallest disparity on the Randot preschool test reported accurately.
Angle of strabismus pre-intervention
Prismatic power required to neutralise the angle of deviation on prism cover test (cover/uncover test).
Angle of strabismus post-intervention
Prismatic power required to neutralise the angle of deviation on prism cover test (cover/uncover test).
Angle of strabismus during intervention
Prismatic power required to neutralise the angle of deviation on prism cover test (cover/uncover test).
Amblyopic eye fixation stability pre-intervention
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Amblyopic eye fixation stability post-intervention
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Amblyopic eye fixation stability during intervention
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Fellow (non-amblyopic) eye fixation stability pre-intervention
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Fellow (non-amblyopic) eye fixation stability post-intervention
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Fellow (non-amblyopic) eye fixation stability during intervention
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Interocular suppression pre-intervention
Computer-based measurement of interocular suppression.
Interocular suppression post-intervention
Computer-based measurement of interocular suppression.
Interocular suppression during intervention
Computer-based measurement of interocular suppression.
Quality of life pre-intervention
Questionnaire scores for: Amblyopia and Strabismus Questionnaire World Health Organization Quality of Life-BREF
Quality of life post-intervention
Questionnaire scores for: Amblyopia and Strabismus Questionnaire World Health Organization Quality of Life-BREF

Full Information

First Posted
May 19, 2022
Last Updated
September 4, 2023
Sponsor
Centre for Eye and Vision Research
Collaborators
The Hong Kong Polytechnic University, University of Waterloo
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1. Study Identification

Unique Protocol Identification Number
NCT05394987
Brief Title
Optical Correction and Visual Functions of Adults With Amblyopia
Acronym
SPECTRA
Official Title
Spectacle Correction for the Treatment of Amblyopia
Study Type
Interventional

2. Study Status

Record Verification Date
September 2023
Overall Recruitment Status
Recruiting
Study Start Date
June 13, 2022 (Actual)
Primary Completion Date
November 30, 2026 (Anticipated)
Study Completion Date
May 31, 2027 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Centre for Eye and Vision Research
Collaborators
The Hong Kong Polytechnic University, University of Waterloo

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
Amblyopia is a developmental anomaly resulting from abnormal visual experiences in early life. Amblyopia causes reduced visual acuity in the absence of a pathology. Adult sensory systems are believed to be structurally invariant beyond early, critical periods of development. However, recent evidence suggest that visual functions in adults with amblyopia can be improved with optical correction alone. This study aims to investigate whether improvements in best corrected visual acuity and other visual functions can result following appropriate optical correction in adults with amblyopia. Functional measures relating to vision, binocular vision, and eye movements will be used to assess the efficacy of refractive correction for improving vision. This study will help us better understand the improvements in visual functions following optical correction, as well as the mechanisms underlying neuroplasticity in adults with amblyopia.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Amblyopia
Keywords
Amblyopia, Binocular vision, Suppression, Plasticity, Optical correction

7. Study Design

Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Model Description
Within-subject, pre-post interventional study, measuring the effect of optical correction on visual function.
Masking
None (Open Label)
Allocation
N/A
Enrollment
55 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Optical correction
Arm Type
Experimental
Arm Description
Prescription of spectacles for full-time wear to correct refractive error
Intervention Type
Device
Intervention Name(s)
Spectacles
Intervention Description
Prescription of refractive error correction in spectacles. Refractive error will be determined as part of a standard optometric eye exam (performed by a registered optometrist). Guidelines for optical correction for the prescription of the study spectacles (based on Pediatric Eye Disease Investigator Group [PEDIG] amblyopia clinical trial protocols): Hypermetropia - not under-corrected by more than +1.50D spherical equivalent and the reduction in plus sphere must be identical between the two eyes. Anisometropia - full correction of the anisometropic difference. Astigmatism - full cylinder power prescribed. Appropriate refractive error correction will be prescribed. Participants will be instructed to wear the optical correction full-time (i.e., more than 50% of waking hours) for the duration of the study.
Primary Outcome Measure Information:
Title
Best corrected visual acuity of the amblyopic eye pre-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Best corrected visual acuity of the amblyopic eye post-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Secondary Outcome Measure Information:
Title
Best corrected visual acuity of the amblyopic eye during intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Fellow eye distance visual acuity pre-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Fellow eye distance visual acuity post-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Fellow eye distance visual acuity during-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Binocular distance visual acuity pre-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Binocular distance visual acuity post-intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Binocular distance visual acuity during intervention
Description
The size of the smallest line of letters read accurately on an ETDRS chart.
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Near visual acuity of amblyopic eye pre-intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Near visual acuity of amblyopic eye post-intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Near visual acuity of amblyopic eye during intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins,every 4 weeks from start of intervention
Title
Near visual acuity of fellow eye pre-intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Near visual acuity of fellow eye post-intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Near visual acuity of fellow eye during intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Near binocular visual acuity pre-intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Near binocular visual acuity post-intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Near binocular visual acuity during intervention
Description
The size of the smallest line of letters read accurately on a near ETDRS chart.
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Amblyopic eye contrast sensitivity pre-intervention
Description
Computer-based measurement of contrast sensitivity
Time Frame
Approx. 10 mins, baseline (day 1 of spectacle wear)
Title
Amblyopic eye contrast sensitivity post-intervention
Description
Computer-based measurement of contrast sensitivity
Time Frame
Approx. 10 mins, on completion of study (week 24)
Title
Amblyopic eye contrast sensitivity during intervention
Description
Computer-based measurement of contrast sensitivity
Time Frame
Approx. 10 mins, every 4 weeks from start of intervention
Title
Stereopsis pre-intervention
Description
Smallest disparity on the Randot preschool test reported accurately.
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Stereopsis post-intervention
Description
Smallest disparity on the Randot preschool test reported accurately.
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Stereopsis during intervention
Description
Smallest disparity on the Randot preschool test reported accurately.
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Angle of strabismus pre-intervention
Description
Prismatic power required to neutralise the angle of deviation on prism cover test (cover/uncover test).
Time Frame
Approx. 5 mins,baseline (day 1 of spectacle wear)
Title
Angle of strabismus post-intervention
Description
Prismatic power required to neutralise the angle of deviation on prism cover test (cover/uncover test).
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Angle of strabismus during intervention
Description
Prismatic power required to neutralise the angle of deviation on prism cover test (cover/uncover test).
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Amblyopic eye fixation stability pre-intervention
Description
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Amblyopic eye fixation stability post-intervention
Description
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Amblyopic eye fixation stability during intervention
Description
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Fellow (non-amblyopic) eye fixation stability pre-intervention
Description
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Time Frame
Approx. 5 mins, baseline (day 1 of spectacle wear)
Title
Fellow (non-amblyopic) eye fixation stability post-intervention
Description
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Time Frame
Approx. 5 mins, on completion of study (week 24)
Title
Fellow (non-amblyopic) eye fixation stability during intervention
Description
Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA).
Time Frame
Approx. 5 mins, every 4 weeks from start of intervention
Title
Interocular suppression pre-intervention
Description
Computer-based measurement of interocular suppression.
Time Frame
Approx. 10 mins, baseline (day 1 of spectacle wear)
Title
Interocular suppression post-intervention
Description
Computer-based measurement of interocular suppression.
Time Frame
Approx. 10 mins, on completion of study (week 24)
Title
Interocular suppression during intervention
Description
Computer-based measurement of interocular suppression.
Time Frame
Approx. 10 mins, every 4 weeks from start of intervention
Title
Quality of life pre-intervention
Description
Questionnaire scores for: Amblyopia and Strabismus Questionnaire World Health Organization Quality of Life-BREF
Time Frame
Approx.15-20 mins, baseline (day 1 of spectacle wear)
Title
Quality of life post-intervention
Description
Questionnaire scores for: Amblyopia and Strabismus Questionnaire World Health Organization Quality of Life-BREF
Time Frame
Approx. 15-20 mins, on completion of study (week 24)
Other Pre-specified Outcome Measures:
Title
Electrical potentials pre-intervention
Description
Electroencephalography (EEG) measures: Visual evoked potentials for high and low contrast stimuli (monocular and binocular) Resting state potentials
Time Frame
Approx. 60 mins, baseline (day 1 of spectacle wear)
Title
Electrical potentials post-intervention
Description
Electroencephalography (EEG) measures: Visual evoked potentials for high and low contrast stimuli (monocular and binocular) Resting state potentials
Time Frame
Approx. 60 mins, on completion of study (week 24)
Title
Electrical potentials during intervention
Description
Electroencephalography (EEG) measures: Visual evoked potentials for high and low contrast stimuli (monocular and binocular) Resting state potentials
Time Frame
Approx. 60 mins, 12 weeks from baseline (day 1 of spectacle wear)

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
39 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: 18-39 (inclusive) years of age Anisometropic amblyopia (difference of ≥0.50D spherical equivalent or ≥1.50D astigmatism between eyes) or mixed mechanism amblyopia (strabismus and anisometropia) Best corrected visual acuity (BCVA) in the amblyopic eye of 0.3 logMAR to 1.0 logMAR (inclusive) BCVA in the non-amblyopic eye of 0.1 logMAR or better, and an interocular VA difference of 2 logMAR lines or more Difference of 1.00D or more between current refractive correction and study prescription Good general health Exclusion Criteria: Other pathological ocular anomalies known to cause reduced visual acuity Presbyopia (based on amplitude of accommodation) Inability to tolerate full refractive correction in spectacles (e.g., due to aniseikonia) Contraindication to cycloplegic eye drops (only when necessary for assessing residual refractive error) Currently under amblyopia treatment/therapy Inability to comprehend test instructions and/or provide consent Eccentric fixation and/or abnormal retinal correspondence >-6.00DS of myopia in either eye with spectacles Bilateral amblyopia Presence of amblyopia that is not due to strabismus and/or anisometropia Presence of (current or previous) attention disorder, learning disability, psychiatric, visual, or neurological disorders
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Benjamin Thompson, PhD
Phone
+852-3169-9631
Email
ben.thompson@cevr.hk
First Name & Middle Initial & Last Name or Official Title & Degree
Ken WS Tan, PhD
Phone
+852-3169-9631
Email
ken.tan@cevr.hk
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Benjamin Thompson, PhD
Organizational Affiliation
Centre for Eye and Vision Research Limited
Official's Role
Principal Investigator
First Name & Middle Initial & Last Name & Degree
Ken WS Tan, PhD
Organizational Affiliation
Centre for Eye and Vision Research Limited
Official's Role
Study Director
Facility Information:
Facility Name
Centre for Eye and Vision Research Limited
City
Hong Kong
State/Province
Guangdong
ZIP/Postal Code
00000
Country
Hong Kong
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Peter CK Pang, PhD
Phone
+852-2766-7927
Email
csm@cevr.hk
First Name & Middle Initial & Last Name & Degree
Adela SY Park, PhD
First Name & Middle Initial & Last Name & Degree
Peter CK Pang, PhD
First Name & Middle Initial & Last Name & Degree
Allen MY Cheong, PhD
First Name & Middle Initial & Last Name & Degree
Nianzeng Zhong, PhD

12. IPD Sharing Statement

Plan to Share IPD
Yes
IPD Sharing Plan Description
Anonymized data will be shared on request
IPD Sharing Time Frame
After publication of study results for an indefinite period.
IPD Sharing Access Criteria
Upon reasonable request and approved by the study principal investigator.

Learn more about this trial

Optical Correction and Visual Functions of Adults With Amblyopia

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