Effectiveness of Telescopic Magnification in the Treatment of Amblyopia

NCT00970554 | Completed Phase 1

• 1 other identifier: 1000011712
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

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).

Conditions

Amblyopia

Keywords

Amblyopia; Telescopic magnification; Patching

Outcome Measures

Primary Outcomes (1)

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

  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.

  17 weeks

Study Arms (2)

Patching only

ACTIVE COMPARATOR

Other: Patching

Patching plus telescope group

EXPERIMENTAL

Other: Telescopic magnification

Interventions

Patching OTHER

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

Patching only

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.

Patching plus telescope group

Eligibility Criteria

• Age: 4 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• The Hospital for Sick Children: lead

Study Sites (1)

The Hospital for Sick Children

Toronto, Ontario, Canada

Location

Related Publications (1)

• 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.

  PMID: 20212198 DERIVED

MeSH Terms

Conditions

Amblyopia

Condition Hierarchy (Ancestors)

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

Study Officials

• Agnes Wong, MD

  The Hospital for Sick Children, Toronto, Canada

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Ophthamologist-In-Chief

Study Record Dates

• First Submitted: September 1, 2009
• First Posted: September 2, 2009
• Study Start: December 1, 2007
• Primary Completion: May 1, 2009
• Study Completion: May 1, 2009
• Last Updated: August 27, 2013

Record last verified: 2013-08

Locations

CA (1)