Convergence Insufficiency Treatment Trial (CITT)

• Are Home-based Pencil Push-up therapy, Home-based Pencil Push-ups with Computer Vision Therapy/Orthoptics or Office-based VT/Orthoptics more effective than placebo treatment, and are there differences between the three treatments in improving subject symptoms and signs?
• To evaluate whether improvements in outcome measures are still present after one year of observation.

Convergence insufficiency is a prevalent and distinct binocular vision disorder. Typical symptoms include double vision, eyestrain, headaches, and blurred vision while reading. It affects approximately 5% of children in the United States, and may have a serious impact on an individual's performance in school, choice of jobs, and quality of life.

There is no consensus regarding the most effective treatment for convergence insufficiency. Two commonly prescribed treatments are home-based pencil push-up therapy and office-based vision therapy/orthoptics. Significant differences exist between these two treatment modalities in cost and number of office visits required, with pencil push-up therapy being less expensive and less time intensive. There have been no well-designed studies that have compared the effectiveness of these two treatments.

The Convergence Insufficiency Treatment Trial (CITT) is a prospective, masked, placebo-controlled, multi-center clinical trial in which 208 subjects between the ages of 9 to < 18 years will be randomly assigned to: 1) Home-based Pencil Push-Up Therapy, 2) Home-based Pencil Push-ups with Computer Vision Therapy/Orthoptics, 3) Office-based Vision Therapy/Orthoptics, or 4) Placebo Office-based Vision Therapy/Orthoptics. The primary outcome measure is a measure of symptoms using a 15-item survey, the CI Symptom Survey. Secondary outcome measures are two common clinical tests of the eyes' ability to converge when performing close work. Patients will be tested at the eligibility examination, and by masked examiners after 4, 8 and 12 weeks of treatment have been completed during the 12-week treatment phase. Long term follow-up will be assessed at 6 and 12 months after the completion of active treatment.

Inclusion criteria:

• Children between the ages of 9 and 17 years with symptomatic convergence insufficiency
• Exophoria at near at least 4Δ greater than at far
• Insufficient positive fusional convergence at near
• A receded near point of convergence of ≥6 cm break
• CI Symptom Survey score ≥16

• Previous treatment with office-based vision therapy/orthoptics or pencil push-ups
• Systemic diseases known to affect accommodation, vergence and ocular motility
• Developmental disability, mental retardation, attention deficit hyperactivity disorder (ADHD), or learning disability diagnosis that in the investigator's discretion would interfere with treatment

No longer recruiting. Comments: Recruitment began in July 2005. A total 221 children aged 9 to 17 years with symptomatic convergence insufficiency were enrolled and assigned to 1 of 4 treatments.

Ongoing. Comments: The study is ongoing with results from 12 weeks of treatment published. A 12-month follow up study is planned.

After 12 weeks of treatment, nearly 75 percent of children who were given the office-based vision therapy along with at-home reinforcement achieved normal vision or had significantly fewer symptoms of CI. Only 43 percent of patients who completed home-based therapy alone showed similar results, as did 33 percent of patients who used home-based pencil push-ups plus computer therapy and 35 percent of patients given a placebo office-based therapy.