A Randomized Trial of Base-in Prism Reading Glasses Convergence Insufficiency in Children

A Randomized Clinical Trial of the Effectiveness of Base-in Prism Reading Glasses Vs. Placebo Reading Glasses for Symptomatic Convergence Insufficiency in Children

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00347581

Enrollment

Registered

2006-07-04

Start date

2003-05-31

Completion date

2004-08-31

Last updated

2006-07-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Convergence Insufficiency

Keywords

convergence insufficiency, base-in prism, orthoptics, vision therapy

Brief summary

This study is designed to compare the use of special prism glasses to placebo treatment for children with symptomatic convergence insufficiency.

Detailed description

The Base-in for Convergence Insufficiency Treatment Trial (BI-CITT) is a multi-center, placebo-controlled, masked, clinical trial designed to compare the benefits of base-in prism for patients with convergence insufficiency (CI). The goals of this clinical trial are: * To compare the effectiveness of Base-in prism and Placebo eyeglasses for the treatment of CI in children * To study the long-term effect of these treatments for CI * To identify factors that may be associated with successful treatment of CI with base-in prism

Interventions

PROCEDUREBase-in prism glasses for reading

PROCEDUREPlacebo reading glasses

Study design

Allocation

RANDOMIZED

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

DOUBLE

Eligibility

Sex/Gender

ALL

Age

9 Years to 18 Years

Healthy volunteers

Yes

Inclusion criteria

* Age: 9 to \<19 years. * Best corrected visual acuity of ≥20/25 in each eye at distance and near * Willingness to wear eyeglasses or contact lenses to correct refractive error, if necessary * Willingness to wear glasses for reading and other near work * Exophoria at near at least 4 greater than at far * Insufficient positive fusional convergence (fails Sheard's criterion) * Receded near point of convergence of  6 cm break * Random dot stereopsis appreciation using a 500 seconds of arc target. * CI Symptom Survey score  16

Exclusion criteria

* Amblyopia (\> 2 line difference in best corrected visual acuity between the two eyes). * Constant strabismus * History of strabismus surgery. * Anisometropia  2D in any meridian between the eyes. * Prior refractive surgery. * Vertical heterophoria greater than 1 . * Systemic diseases known to affect accommodation, vergence and ocular motility such as: multiple sclerosis, Graves thyroid disease, myasthenia gravis, diabetes, Parkinson disease. * Any ocular or systemic medication known to affect accommodation or vergence (Anti-anxiety agents (Librium or Valium), Anti-arrhythmic agents (Cifenline or Cibenzoline), Anticholinergics (Motion sickness patch (scopolamine), Bladder spasmolytic drugs (Propiverine), Chloroquine, Phenothiazines (Compazine, Mellaril, or Thorazine), Tricyclic antidepressants (Elavil, Nortriptyline, or Tofranil) * Accommodative amplitude \<5 D in either eye as measured by the Donder's push-up method. * Manifest or latent nystagmus. * Developmental disability, mental retardation, attention deficit hyperactivity disorder (ADHD), or learning disability diagnosis in children that in the investigator's discretion would interfere with treatment. * Household member or sibling already enrolled in the BI-CITT. * Any eye care professional, ophthalmic technician, ophthalmology or optometry resident or optometry student.

Design outcomes

Primary

Measure	Time frame
Symptom score on the Convergence Insufficiency Symptom Survey	—

Secondary

Measure	Time frame
Near point of convergence	—
Positive fusional vergence at near	—

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026