Randomized Trial of Treatments for Convergence Insufficiency

• The primary outcome measure is the score on the Convergence Insufficiency Symptom Survey
  

• Near Point of Convergence
  
• Positive Fusional Vergence at Near
  

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?