Skip to main content
OpenTrials
Completed

NCT Number: NCT00970554

Effectiveness of Telescopic Magnification in the Treatment of Amblyopia

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).

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Amblyopia Brain Diseases Central Nervous System Diseases Eye Diseases Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Vision Disorders

Age range

4 year–17 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1 / Phase 2

Primary location

The Hospital for Sick Children

Toronto, Ontario, Canada

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Patching

Other

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

Telescopic magnification

Other

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 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

Sponsors and collaborators

Lead sponsor

The Hospital for Sick Children

Other

Registry information

Important dates

Study start
2007
Primary completion
2009
Study completion
2009
First posted
Sep 2, 2009
Registry last updated
Aug 27, 2013

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.