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A Randomized Trial Comparing Part-time Versus Minimal-time Patching for Moderate Amblyopia

Purpose | Background | Description | Patient Eligibility | Recruitment Status | Current Status | Results | Publications | Resource Centers | NEI Representative



Amblyopia is the most common cause of monocular visual impairment in both children and young and middle-aged adults. Patching has been the mainstay of amblyopia therapy. It is generally held that the response to treatment is best when it is instituted at an early age, particularly by age two or three, and is poor when attempted after eight years of age.

For moderate amblyopia, patching is the most commonly prescribed treatment although other modalities such as atropine penalization are also prescribed. There is no specific patching regimen that is widely accepted for treatment of moderate amblyopia and limited or no data available to favor the use of one specific regimen; both minimal occlusion (e.g., 2 hours per day) and six or more hours per day of patching are prescribed in clinical practice.


The study is a randomized trial comparing daily patching regimes for children with moderate amblyopia. It will consist of about 160 children. Patients in the moderate (20/40-20/80) group will patch part-time (6 hours) or minimal time (2 hours) of each day for the 4-month study period. There are at least two follow up visits during the 4-month period. Visual acuity is the major study outcome. It is assessed at the 4-month exam.

Patient Eligibility

Patients must be less than 7 years of age with original cause of amblyopia due strabismus or anisometropia. Visual Acuity in the amblyopic eye must be between 20/40 and 20/80, visual acuity in the sound eye of 20/40 or better and there must be at least 3 lines of acuity difference between the two eyes. Patients must have had no patching treatment (other than spectacles) within six months prior to enrollment and no other amblyopia treatment of any type used within one month prior to enrollment.

Patient Recruitment Status

Completed. Recruitment began in May 2001 and closed in May 2002 after 189 patients were enrolled.

Current Status of Study



For moderate amblyopia, prescribing two hours of daily patching produces an improvement in visual acuity that is of similar magnitude to the improvement produced by prescribing six hours of daily patching in children 3 to less than 7 years of age.


The Pediatric Eye Disease Investigator Group: A randomized trial of patching regimens for treatment of moderate amblyopia in children. . Arch Ophthalmol 121: 603-611, 2003.

Resource Centers

Co-Chairman's Office
Jonathan M. Holmes, M.D.
Mayo Clinic
Department of Ophthalmology W7
200 First Street Southwest
Rochester, MN 55905
Telephone: (507) 284-3760
Fax: (507) 284-8566

Michael X. Repka, M.D.
Wilmer Eye Institute
233 Wilmer Institute
600 N. Wolfe Street
Baltimore, MD 21287-9028
Telephone: (410) 955-0809
Fax: (410) 955-8314

Data Coordination Center
Roy W. Beck, Ph.D.
Pamela S. Moke, M.S.P.H.
Raymond T. Kraker, M.S.P.H.
Heidi A. Gillespie
Alisha N. Lawson
Nicole M. Boyle
Julie A. Gillett
Shelly T. Mares
Brian B. Dale
Jaeb Center for Health Research
3010 E 138th Avenue
Suite 9
Tampa, FL 33613
Telephone: (813) 975-8690
Fax: (813) 975-8761

Data and Safety Monitoring Committee

William Barlow, Ph.D.
Group Health Cooperative
Seattle, WA

Edward G. Buckley, M.D.
Duke University Medical Center
Durham, NC

Barry Davis, M.D., Ph.D.
University of Texas
Houston, TX

Velma Dobson, Ph.D.
University of Arizona
Tucson, AZ

John L. Keltner, M.D
University of California
Sacramento, CA

Hana Osman, Ph.D.
Louis de la Parte Florida Mental Health Institute
Tampa, FL

Earl A. Palmer, M.D.
Casey Eye Institute
Portland, OR

Dale L. Phelps, M.D.
University of Rochester
Rochester, NY

NEI Representative

Donald F. Everett, M.A.
National Eye Institute
6120 Executive Boulevard, MSC 7164
Executive Plaza South, Suite 350
Bethesda, MD 20892-7164
Telephone: (301) 496-5983
Fax: (301) 402-0528

Steering Committee

Roy W. Beck, M.D., Ph.D
Jaeb Center for Health Research
Tampa, FL

Eileen Birch, Ph.D.
Retina Foundation of the Southwest
Dallas, TX

Susan A. Cotter, O.D.
Southern California College of Oprometry
Fullerton, CA

Donald F. Everett, M.A.
National Eye Institute
Bethesda, MD

Richard W. Hertle, M.D.
Pediatric Ophthalmology Associate, Inc
Colombus, OH

Jonathan M. Holmes, M.D.
Mayo Clinic
Rochester, MN

Pamela S. Moke, M.S.P.H.
Jaeb Center for Health Research
Tampa, FL

Michael X. Repka, M.D.
Johns Hopkins University
Baltimore, MD

Mitchll M. Scheiman, O.D.
Pennsylvania College of Optometry
Philadelphia, PA

Last Updated: 3/15/2004

Department of Health and Human Services NIH, the National Institutes of Health