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CompletedNCT00970554Updated Aug 27, 2013

Effectiveness of Telescopic Magnification in the Treatment of Amblyopia

A Phase 1/2 interventional study of Patching and Telescopic magnification in Amblyopia, sponsored by The Hospital for Sick Children. Completed at 1 site in Canada. Open to participants aged 4 Years to 17 Years. Per ClinicalTrials.gov, last updated 2013-08-27.

Sponsored by The Hospital for Sick Children · Phase 1/2, Interventional, and Treatment

Phase
Phase 1/2
Study type
Interventional
Enrollment
15
Allocation
Randomized
Ages
4 Years to 17 Years
Sex
All
01

Study 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).

Read the 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.

02

Conditions studied

  • Amblyopia

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Keywords

  • Amblyopia
  • Telescopic magnification
  • Patching
03

In context

Amblyopia

183 studies on the registry are indexed under Amblyopia; 43 are open to participants now.

This study's enrollment of 15 is below the median of 60 across 133 interventional studies indexed under Amblyopia.

Browse Amblyopia studies →

Lead sponsor

The Hospital for Sick Children is the lead sponsor of 568 studies on the registry; 81 are open to participants now.

Of its 7 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
4 Years to 17 Years
Sexes eligible
All
Accepts healthy volunteers
No

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

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
05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
15 participants (actual)

Study arms

  • Active comparator
    Patching only

    Other: Patching

  • Experimental
    Patching plus telescope group

    Other: Telescopic magnification

Interventions

  • OtherPatching

    Patching of the sound eye for 30 minutes a day for 17 weeks.

  • OtherTelescopic magnification

    Patching of the sound eye plus simultaneous use of a telescopic device by the amblyopic eye for 30 minutes a day for 17 weeks.

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What researchers measure

Primary outcomes

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

    Time frame: 17 weeks

Secondary outcomes

  1. 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

07

Study locations

1 site
  • The Hospital for Sick Children
    Toronto, Ontario, Canada
08

References and documents

Publications

  • 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. PubMed 20212198 ↗
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 27, 2013, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT00970554
Lead sponsor
The Hospital for Sick Children
Responsible party
Agnes Wong (Ophthamologist-In-Chief, The Hospital for Sick Children) — Principal investigator
First posted
Sep 2, 2009
Start date
Dec 2007
Primary completion
May 2009
Completion
May 2009
Last update
Aug 27, 2013

Study contacts

Agnes Wong, MD
principal investigator · The Hospital for Sick Children, Toronto, Canada

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Aug 2013. You cannot join it, but the record below documents what was studied.

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