Randomized Trial of Treatments for Convergence Insufficiency

Sponsor

Pennsylvania College of Optometry (Industry)

Overall Status

Completed

CT.gov ID

NCT00347945

Collaborator

National Eye Institute (NEI) (NIH)

Enrollment

Locations

Duration (Months)

12.9

Patients Per Site

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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 or Disease	Intervention/Treatment	Phase
Convergence Insufficiency	Procedure: Pencil Push-ups Procedure: Office-based Vision Therapy Procedure: Placebo Office-based Vision Therapy	Phase 3

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:

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?
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?

Study Design

Study Type:

Interventional

Allocation:

Randomized

Intervention Model:

Single Group Assignment

Masking:

Single

Primary Purpose:

Treatment

Official Title:

A Randomized Clinical Trial of Pencil Push-Ups Versus Office Based Vision Therapy For the Treatment of Convergence Insufficiency

Study Start Date :

Oct 1, 2000

Study Completion Date :

Nov 1, 2001

Outcome Measures

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 []

Eligibility Criteria

Criteria

Ages Eligible for Study:

9 Years to 30 Years

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

Locations

	Site	City	State	Country	Postal Code
1	Southern California College of Optometry	Fullerton	California	United States	92831
2	State University of New York, College of Optometry	New York	New York	United States	10036
3	The Ohio State University, Optometry Coordinating Center	Columbus	Ohio	United States	43210
4	The Ohio State University	Columbus	Ohio	United States	43210
5	Pacific University College of Optometry	Forest Grove	Oregon	United States	97116
6	Eye Institute, Pennsylvania College of Optometry	Philadelphia	Pennsylvania	United States	19141
7	University of Houston, College of Optometry	Houston	Texas	United States	77204

Sponsors and Collaborators

Pennsylvania College of Optometry
National Eye Institute (NEI)

Investigators

Study Chair: Mitchell Scheiman, OD, Pennsylvania College of Optometry

Study Documents (Full-Text)

None provided.

More Information

Additional Information:

Study Website

Publications

Responsible Party:

, ,

ClinicalTrials.gov Identifier:

NCT00347945

Other Study ID Numbers:

HMS2040
1R21EY13164-1

First Posted:

Jul 4, 2006

Last Update Posted:

Jul 4, 2006

Last Verified:

Jan 1, 2002

Keywords provided by , ,

convergence insufficiency, vision therapy, orthoptics

Additional relevant MeSH terms:

Ocular Motility Disorders

Study Results

No Results Posted as of Jul 4, 2006