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Randomized Trial of Treatments for Convergence Insufficiency

This study has been completed.
National Eye Institute (NEI)
Information provided by:
Pennsylvania College of Optometry Identifier:
First received: July 3, 2006
Last updated: NA
Last verified: January 2002
History: No changes posted
The Convergence Insufficiency Treatment Trial (CITT) is a multi-center, placebo-controlled, single-masked, clinical trial designed to compare the benefits of two commonly used treatment approaches for patients with convergence insufficiency (CI)

Condition Intervention Phase
Convergence Insufficiency Procedure: Pencil Push-ups Procedure: Office-based Vision Therapy Procedure: Placebo Office-based Vision Therapy Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single Blind
Primary Purpose: Treatment
Official Title: A Randomized Clinical Trial of Pencil Push-Ups Versus Office Based Vision Therapy For the Treatment of Convergence Insufficiency

Resource links provided by NLM:

Further study details as provided by Pennsylvania College of Optometry:

Primary Outcome Measures:
  • The primary outcome measure is the score on the Convergence Insufficiency Symptom Survey

Secondary Outcome Measures:
  • Near Point of Convergence
  • Positive Fusional Vergence at Near

Estimated Enrollment: 90
Study Start Date: October 2000
Estimated Study Completion Date: November 2001
Detailed Description:

Considerable controversy exists regarding the best treatment for convergence insufficiency (CI), a common condition that often interferes with the ability to perform near work. The two most widely used treatments have significant differences in costs and in practitioner perceived utility. Pencil push-up therapy (PPT) is a simple, low-cost treatment in which patients are prescribed a single procedure to perform at home with only periodic follow-up. Office-based vision therapy (OBVT) is a more comprehensive, time-consuming, complex, and costly treatment in which patients are scheduled for weekly in-office therapy visits and are often prescribed a specific sequence of therapeutic procedures to perform at home. It is important to consider whether either, neither, or both treatments are effective.

The Convergence Insufficiency Treatment Trial (CITT) is a prospective, masked-examiner, multi-center clinical trial in which patients are randomized to one of these two treatment approaches. The primary goal is to answer the following question:

After 12 weeks of treatment, is one therapy more effective than the other in improving CI signs and symptoms? We will test the null hypothesis that there is no difference in the distribution of outcomes between the two populations.

The primary outcome measure will be a classification of each patient as a “success,” “improvement,” or “failure.” This classification will be based on the level of improvement in both the signs (near point of convergence and positive fusional vergence) and symptoms of CI.

Additional questions relate to longer term effects:

  1. Are the patients who were classified as “success” or “improvement” at twelve weeks the same at the one-year follow-up for each treatment group?
  2. Are there differences in the distributions of changes in near point of convergence, positive fusional vergence, or accommodative amplitudes, between the two treatment groups, at twelve weeks and at one-year of follow up?

Ages Eligible for Study:   9 Years to 30 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 9-30 years
  • Best corrected visual acuity of 20/25 in both eyes at distance and near
  • Willingness to wear eyeglasses or contact lenses to correct refractive error, if necessary
  • Exophoria at near at least 4 prism diopters greater than at far
  • Insufficient positive fusional convergence (i.e., failing Sheard’s criterion or minimum normative positive fusional vergence (PFV) of 15 base-out break).
  • Receded near point of convergence of > 6 cm break.
  • Normal random dot stereopsis using a 500 seconds of arc target.
  • CI Symptom Survey score > 16 for subjects in 9-18 year age range and > 21 for subjects in the 19-30 year age range.
  • Informed consent and willingness to participate in the study and be randomized

Exclusion Criteria:

  • CI previously treated with pencil push-ups (no more than 2 months of treatment within the past year)
  • CI previously treated with office-based vision therapy/orthoptics (no more than 2 months of treatment within the past year)
  • Amblyopia
  • Constant strabismus
  • History of strabismus surgery
  • Anisometropia >1.50D difference between eyes
  • Prior refractive surgery
  • Vertical heterophoria greater than 1 
  • Systemic diseases known to affect accommodation, vergence, and ocular motility such as: multiple sclerosis, Graves’s thyroid disease, myasthenia gravis, diabetes, and Parkinson disease
  • Any ocular or systemic medication known to affect accommodation or vergence
  • Monocular accommodative amplitude less than 4 D in either eye as measured by the Donder’s push-up method
  • Manifest or latent nystagmus
  • Attention deficit hyperactivity disorder (ADHD) or learning disability diagnosis by parental report
  • Household member or sibling already enrolled in the CITT
  • Any eye care professional, technician, medical student, or optometry student
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00347945

United States, California
Southern California College of Optometry
Fullerton, California, United States, 92831
United States, New York
State University of New York, College of Optometry
New York, New York, United States, 10036
United States, Ohio
The Ohio State University, Optometry Coordinating Center
Columbus, Ohio, United States, 43210
The Ohio State University
Columbus, Ohio, United States, 43210
United States, Oregon
Pacific University College of Optometry
Forest Grove, Oregon, United States, 97116
United States, Pennsylvania
Eye Institute, Pennsylvania College of Optometry
Philadelphia, Pennsylvania, United States, 19141
United States, Texas
University of Houston, College of Optometry
Houston, Texas, United States, 77204
Sponsors and Collaborators
Pennsylvania College of Optometry
National Eye Institute (NEI)
Study Chair: Mitchell Scheiman, OD Pennsylvania College of Optometry
  More Information

Additional Information:
Publications: Identifier: NCT00347945     History of Changes
Other Study ID Numbers: HMS2040
Study First Received: July 3, 2006
Last Updated: July 3, 2006

Keywords provided by Pennsylvania College of Optometry:
convergence insufficiency, vision therapy, orthoptics

Additional relevant MeSH terms:
Ocular Motility Disorders
Central Nervous System Diseases
Nervous System Diseases
Cranial Nerve Diseases
Eye Diseases processed this record on August 16, 2017