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Effectiveness of Telescopic Magnification in the Treatment of Amblyopia

Primary Purpose

Amblyopia

Status
Completed
Phase
Phase 1
Locations
Canada
Study Type
Interventional
Intervention
Patching
Telescopic magnification
Sponsored by
The Hospital for Sick Children
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Amblyopia focused on measuring Amblyopia, Telescopic magnification, Patching

Eligibility Criteria

4 Years - 17 Years (Child)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • Aged 4-17 years

  • Strabismic, refractive (anisometropic), isometropic or mixed mechanism amblyopia

    • Strabismic amblyopia is defined as amblyopia (1) in the presence of either an inability to maintain parallel visual axes (heterotropia) at distance or near fixation or both, or a history of strabismus surgery (or botulinum injection), and (2) in the absence of refractive error meeting the criteria below for mixed mechanism amblyopia
    • Refractive/Anisometropic amblyopia is defined as amblyopia in the presence of a difference in refractive error between the two eyes (anisometropia) of ≥0.5 diopter (D) of spherical equivalent or ≥1.5D of difference in astigmatism in any meridian, with no measurable heterophoria at distance or near fixation, which persisted after 12 weeks of spectacle correction
    • Isometropic amblyopia is defined as amblyopia in the presence a refractive error ≥5.0D of spherical equivalent in both eyes, but not meeting the criteria of anisometropic amblyopia
    • Mixed mechanism strabismic and refractive amblyopia is defined as the presence of both strabismic and anisometropic types of amblyopia
  • Ability to read the ETDRS letter chart
  • Visual acuity between 0.3 and 1.3 logMAR (i.e., between 20/40 and 20/400) in the amblyopic eye
  • Visual acuity of 0.3 logMAR (i.e., 20/40) or better in the sound eye
  • Interocular acuity difference ≥0.3 logMAR
  • Appropriate refractive error correction for at least 12 weeks

Exclusion Criteria:

  • Presence of an ocular cause of reduced visual acuity
  • Myopia with a spherical equivalent of -6.0D or more, due to the likely presence of pathological myopia
  • Prior intraocular surgery
  • Known skin reaction to patch or bandage adhesive

Sites / Locations

  • The Hospital for Sick Children

Arms of the Study

Arm 1

Arm 2

Arm Type

Active Comparator

Experimental

Arm Label

Patching only

Patching plus telescope group

Arm Description

Outcomes

Primary Outcome Measures

The best corrected logMAR visual acuity score of the amblyopic eye.

Secondary Outcome Measures

Visual acuity of at least 0.2 logMAR (20/30) and/or improvement of at least 0.2 logMAR from baseline in the amblyopic eye.

Full Information

First Posted
September 1, 2009
Last Updated
August 26, 2013
Sponsor
The Hospital for Sick Children
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1. Study Identification

Unique Protocol Identification Number
NCT00970554
Brief Title
Effectiveness of Telescopic Magnification in the Treatment of Amblyopia
Official Title
Effectiveness of Telescopic Magnification in the Treatment of Amblyopia
Study Type
Interventional

2. Study Status

Record Verification Date
August 2013
Overall Recruitment Status
Completed
Study Start Date
December 2007 (undefined)
Primary Completion Date
May 2009 (Actual)
Study Completion Date
May 2009 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
The Hospital for Sick Children

4. Oversight

Data Monitoring Committee
No

5. Study Description

Brief Summary
Amblyopia is a visual impairment of one eye that results from disuse of that eye during early brain development. The standard treatment for amblyopia consists of patching or pharmacological penalization of the sound eye. Unfortunately, approximately 50% of amblyopic children do not respond to these therapies, with poor compliance being a major factor in treatment failure. One new treatment strategy involves patching the sound eye while using a telescopic device on the amblyopic eye to magnify the images formed in the amblyopic eye. Children were randomized to receive either daily patching of the sound eye for 30 minutes only (patching only group), or daily patching of the sound eye for 30 minutes plus simultaneous use of a telescopic device by the amblyopic eye during patching (patching plus telescope group).
Detailed Description
The goal of the present investigation was to conduct a prospective randomized clinical study to further evaluate the effectiveness of telescopic magnification plus patching vs patching alone on different types of amblyopia in patients who had failed previous treatment.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Amblyopia
Keywords
Amblyopia, Telescopic magnification, Patching

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 1, Phase 2
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
15 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Patching only
Arm Type
Active Comparator
Arm Title
Patching plus telescope group
Arm Type
Experimental
Intervention Type
Other
Intervention Name(s)
Patching
Intervention Description
Patching of the sound eye for 30 minutes a day for 17 weeks.
Intervention Type
Other
Intervention Name(s)
Telescopic magnification
Intervention Description
Patching of the sound eye plus simultaneous use of a telescopic device by the amblyopic eye for 30 minutes a day for 17 weeks.
Primary Outcome Measure Information:
Title
The best corrected logMAR visual acuity score of the amblyopic eye.
Time Frame
17 weeks
Secondary Outcome Measure Information:
Title
Visual acuity of at least 0.2 logMAR (20/30) and/or improvement of at least 0.2 logMAR from baseline in the amblyopic eye.
Time Frame
17 weeks

10. Eligibility

Sex
All
Minimum Age & Unit of Time
4 Years
Maximum Age & Unit of Time
17 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Aged 4-17 years Strabismic, refractive (anisometropic), isometropic or mixed mechanism amblyopia Strabismic amblyopia is defined as amblyopia (1) in the presence of either an inability to maintain parallel visual axes (heterotropia) at distance or near fixation or both, or a history of strabismus surgery (or botulinum injection), and (2) in the absence of refractive error meeting the criteria below for mixed mechanism amblyopia Refractive/Anisometropic amblyopia is defined as amblyopia in the presence of a difference in refractive error between the two eyes (anisometropia) of ≥0.5 diopter (D) of spherical equivalent or ≥1.5D of difference in astigmatism in any meridian, with no measurable heterophoria at distance or near fixation, which persisted after 12 weeks of spectacle correction Isometropic amblyopia is defined as amblyopia in the presence a refractive error ≥5.0D of spherical equivalent in both eyes, but not meeting the criteria of anisometropic amblyopia Mixed mechanism strabismic and refractive amblyopia is defined as the presence of both strabismic and anisometropic types of amblyopia Ability to read the ETDRS letter chart Visual acuity between 0.3 and 1.3 logMAR (i.e., between 20/40 and 20/400) in the amblyopic eye Visual acuity of 0.3 logMAR (i.e., 20/40) or better in the sound eye Interocular acuity difference ≥0.3 logMAR Appropriate refractive error correction for at least 12 weeks Exclusion Criteria: Presence of an ocular cause of reduced visual acuity Myopia with a spherical equivalent of -6.0D or more, due to the likely presence of pathological myopia Prior intraocular surgery Known skin reaction to patch or bandage adhesive
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Agnes Wong, MD
Organizational Affiliation
The Hospital for Sick Children, Toronto, Canada
Official's Role
Principal Investigator
Facility Information:
Facility Name
The Hospital for Sick Children
City
Toronto
State/Province
Ontario
Country
Canada

12. IPD Sharing Statement

Citations:
PubMed Identifier
20212198
Citation
Wu J, Nazemi F, Schofield J, Mirabella G, Wong AM. Effectiveness of telescopic magnification in the treatment of amblyopia: a pilot study. Arch Ophthalmol. 2010 Mar;128(3):297-302. doi: 10.1001/archophthalmol.2009.400.
Results Reference
derived

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Effectiveness of Telescopic Magnification in the Treatment of Amblyopia

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