Convergence Insufficiency Treatment Study (CITS)
Condition: Convergence Insufficiency
MeSH terms: Ocular Motility Disorders
Study type: Interventional

Summary: 
      The purpose of this study is to determine the effectiveness of home-based computer therapy
      for symptomatic convergence insufficiency (CI) compared to traditional home-based near target
      push-ups and placebo treatment.
    

Detailed description: 
      Convergence insufficiency (CI) is a common and distinct binocular vision disorder that
      affects approximately 4% of school age children and adults in the United States. Convergence
      insufficiency is often associated with symptoms such as frequent loss of place while reading,
      loss of concentration, having to re-read, reading slowly, poor comprehension, sleepiness,
      blurred vision, diplopia, headaches, and/or eyestrain. A recently completed randomized
      clinical trial, the Convergence Insufficiency Treatment Trial (CITT), demonstrated that a
      12-week program of office-based vergence/ accommodative therapy with home reinforcement was
      more effective than home-based near target pencil push-ups, home-based computer accommodative
      therapy plus pencil push-ups, or office-based placebo therapy in treating the symptoms and
      signs associated with symptomatic CI in children 9 to 17 years of age.

      While the home-based therapies in the CITT were not as effective as office-based
      vergence/accommodative therapy there was some improvement noted. Currently, many eye care
      professionals only offer home-based therapy, while others suggest passive treatment with
      base-in prism. At a Pediatric Eye Disease Investigator Group (PEDIG) meeting (Tampa, January
      2009), the results of a poll of attendees indicated that a large majority of pediatric
      ophthalmologists continue to recommend home-based near target push-ups as the initial
      treatment approach for children with symptomatic CI in spite of the CITT results.

      There are significant differences in contact time, complexity, and cost between office-based
      and home-based therapy for CI. Many clinicians believe that the less costly and less complex
      treatment option should be attempted first. Although home-based therapy using computer
      software is becoming more popular, no prospective data are available to demonstrate the
      effectiveness of home-based vision therapy using computer software compared to home-based
      near target push-ups or home-based placebo computer therapy. A prospective clinical trial is
      therefore needed to determine the effectiveness of home-based computer therapy for
      symptomatic CI compared to traditional home-based near target push-ups and placebo treatment.

      The current study is a multi-center randomized clinical trial to evaluate the effectiveness
      of home-based computer vergence/accommodative therapy and home-based near target push-ups in
      children 9 to <18 years of age with symptomatic CI.
    

Intervention name(s): Active home-based computer vergence/accommodative therapy; Near target push-ups; Placebo home-based computer vergence/accommodative therapy; Placebo yoked prism flippers
Intervention type(s): Other; Procedure; Other; Procedure
Intervention description(s): At enrollment, subjects will be prescribed 15 minutes/day of active home-based computer therapy for 5 days/week during the 12 week treatment phase. Active home-based computer therapy will be provided the Home Therapy System (HTS) computer software and will include both fusional vergence and accommodative therapy. Subjects will perform the computer therapy while wearing red/blue glasses and accommodative therapy will be performed using the HTS accommodative flippers. Please refer to the procedures manual for further details.; At enrollment, subjects will be prescribed 15 minutes/day (3 sessions of 5 minutes each) of near target push-ups (NTP) for 5 days/week during the 12-week treatment phase. An alphabet pencil will be used as the target and an index card placed in the background will provide physiological diplopia control. With the pencil positioned at arm's length directly between the subject's eyes, the subject will slowly bring the pencil toward his/her nose while focusing on the small letter on the pencil. When the subject is no longer able to maintain a single image of the pencil, he/she will slowly move the target away from the nose until the pencil becomes single again. This procedure will be repeated several times. Please refer to the procedures manual for further details.; At enrollment, subjects will be prescribed either 5 minutes/day (NTP group) or 15 minutes/day (Placebo group) of placebo home-based computer therapy for 5 days/week during the 12 week treatment phase. Placebo computer-based therapy will be provided by the Home Therapy System (HTS) computer software. The vergence procedures are similar to the active version, however, the tasks will be modified to ensure no demand on the vergence system and no accommodative therapy is included in the placebo version. Please refer to the procedures manual for further details.; Subjects will be prescribed 5 minutes/day of placebo yoked prism flipper therapy for 5 days/week during the 12 week treatment phase. This procedure utilizes a 4 pd base right/4 pd base left prism flipper and "Accommodative Hopping Cards". Subjects view the text on the card through the prisms at 40 cm, perform the appropriate task and then flip the prism flipper to the other side after each word before proceeding to the next line. Please refer to the procedures manual for further details. The task remains constant, but the nature of the procedure changes with time:
Weeks 1-4: View the target through prism flippers
Weeks 5-8: Wear red-blue filter glasses while viewing the text through prism flippers
Weeks 9-12: Wear polaroid glasses while viewing the text through prism flippers
Other intervention name(s): Home Therapy System (HTS, Home Vision Therapy, Inc.); Pencil push-ups; Home Therapy System (HTS, Home Vision Therapy, Inc.)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Convergence insufficiency