Clinical Trial: Convergence Insufficiency Treatment Study (CITS)

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effectiveness of Home-Based Therapy for Symptomatic Convergence Insufficiency

Brief 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 Summary:

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
Sponsor: Jaeb Center for Health Research

Current Primary Outcome:

  • Treatment Group Comparison of the Percentage of Participants Classified as an Overall Success at 12 Weeks - HB-C Versus HB-PU [ Time Frame: 12 weeks after randomization (baseline) ]

    Pairwise treatment group comparison (HB-C versus HB-PU) of the percentages of participants meeting success criteria using binomial regression adjusting for baseline covariates of CISS score (<28 points vs ≥ 28 points), mean NPC break (<10 cm vs ≥ 10 cm), and mean PFV blur (≥ 15 PD vs <15 PD) using linear contrasts with Bonferroni adjustment for multiple comparisons (Type I error rate = 2.5%).

    Overall success was defined as meeting all of the following criteria at 12 weeks:

    1. Convergence Insufficiency Symptom Survey (CISS): 12-week score <16 points and at least 9-point improvement from baseline at 12 weeks
    2. Near point of convergence (NPC) break: 12-week/baseline mean NPC break <0.763 and a mean 12-week NPC break <6 cm
    3. Positive fusional vergence (PFV) blur: 12-week/baseline mean PFV blur >1.419 and a mean 12-week PFV break >15 pd
  • Treatment Group Comparison of the Percentage of Participants Classified as an Overall Success at 12 Weeks - HB-C Versus HB-P [ Time Frame: 12-weeks after randomization (baseline) ]

    Pairwise treatment group comparison (HB-C versus Placebo) of the percentages of participants meeting success criteria using binomial regression adjusting for baseline covariates of CISS score (<28 points vs &

    Original Primary Outcome:

    • Successful treatment of CI for CBT versus NTP comparison [ Time Frame: 12 weeks after randomization ]
      A treatment comparison of the proportion of subjects who are successfully treated for CI at the 12-week visit using logistic regression analysis, adjusting for baseline covariates.
    • Successful treatment of CI for CBT versus placebo comparison [ Time Frame: 12-weeks after randomization ]
      A treatment comparison of the proportion of subjects who are successfully treated for CI at the 12-week visit using logistic regression analysis, adjusting for baseline covariates.


    Current Secondary Outcome:

    • Number of Participants Classified as Having Met Success Criteria Based on CI Signs/Symptoms at 12 Weeks by Treatment Group [ Time Frame: 12 weeks after randomization (baseline) ]
      The number of subjects classified as a success based on signs/symptoms at the 12-week visit. Success is based on the Convergency Insufficiency Symptom Survey (CISS) defined as improvement of 9 or more points from baseline and a 12-week score of <16 points.
    • Number of Participants Classified as Having Met Success Criteria Based on the Mean NPC Break at 12 Weeks by Treatment Group [ Time Frame: 12 weeks after randomization (baseline) ]
      The number of subjects who are classified as a success based on the mean NPC break at the 12-week visit. Success is based on the mean NPC (near point of convergence) break is defined as having a mean NPC break of <6 cm at 12 weeks and a 12-week to baseline ratio of <0.763 for mean NPC break.
    • Number of Participants Classified as Having Met Success Criteria Based on the Mean PFV Blur at 12 Weeks by Treatment Group [ Time Frame: 12 weeks after randomization (baseline) ]
      The number of subjects who are classified as a success based on the mean PFV blur at the 12-week visit. Success is based on the mean PFV (positive fusional vergence) blur, defined as having a mean PFV blur of >15 pd at 12 weeks and a 12-week to baseline ratio of >1.419 for mean PFV blur.
    • Number of Participants Classified as Having Met Success Criteria for Both Clinical Measures at 12 Weeks by Treatment Group [ Time Frame: 12-weeks after randomization (baseline) ]

      The number of subjects classified as a success based on clinical measures of CI (mean NPC break & mean PFV blur) at the 12-week visit. Clinical success is defined according to whether both criteria (below) are met as follows:

      1. Near point of convergence (NPC) break: 12-week/baseline mean NPC break <0.763 and a 12-week mean NPC break <6 cm
      2. Positive fusional vergence (PFV) blur: 12-week/baseline mean PFV blur >1.419 and a 12-week mean PFV blur >15 pd
    • Number of Participants Classified as Having Improved in All 3 Outcomes Measures From Baseline to 12 Weeks by Treatment Group [ Time Frame: 12 weeks after randomization (baseline) ]

      Improvement in all 3 outcome measures at 12 weeks will be defined as follows:

      1. Convergency Insufficiency Symptom Survey (CISS): Improvement of 9 or more points since baseline
      2. Near point of convergence (NPC) break: 12-week/baseline mean NPC break <0.763
      3. Positive fusional vergence (PFV) blur: 12-week/ baseline mean PFV blur >1.419

      (Note: All 3 criteria must be met in order to be classified as an "improver" at the 12-week primary outcome visit).

    • Number of Participants Classified as an Overall Success Based on the 3 Outcomes Measures From Baseline to 6 Weeks by Treatment Group [ Time Frame: 6 weeks after randomization (baseline) ]

      To be considered an overall success, each of the following criteria must be met for the 3 outcome measures at 6 weeks:

      1. Convergence Insufficiency Symptom Survey (CISS): 6-week score <16 points and at least 9-point improvement from baseline at 6 weeks
      2. Near point of convergence (NPC) break: 6-week/baseline mean NPC break <0.763 and a mean 6-week NPC break <6 cm
      3. Positive fusional vergence (PFV) blur: 6-week/baseline mean PFV blur >1.419 and a mean 6-week PFV break >15 pd

      (Note: All 3 criteria must be met in order to be classified as an overall success at the 6-week visit).

    • Number of Participants Classified as Having Met Success Criteria Based on CI Signs/Symptoms at 6 Weeks by Treatment Group [ Time Frame: 6 weeks after randomization (baseline) ]
      The number of subjects classified as a success based on signs/symptoms at the 6-week visit. Success is based on the Convergency Insufficiency Symptom Survey (CISS) defined as improvement of 9 or more points from baseline and a 6-week score of <16 points.
    • Number of Participants Classified as Having Met Success Criteria Based on the Mean NPC Break at 6 Weeks by Treatment Group [ Time Frame: 6 weeks after randomization (baseline) ]
      The number of subjects who are classified as a success based on the mean NPC break at the 6-week visit. Success is based on the mean NPC (near point of convergence) break is defined as having a mean NPC break of <6 cm at 6 weeks and a 6-week to baseline ratio of <0.763 for mean NPC break.
    • Number of Participants Classified

      Original Secondary Outcome:

      • Successful treatment of CI for NTP versus placebo comparison [ Time Frame: 12 weeks after randomization ]
        A treatment comparison of the proportion of subjects who are successfully treated for CI at the 12-week visit using logistic regression analysis, adjusting for baseline covariates.
      • Improvement in all outcome measures (CISS, NPC, PFV) [ Time Frame: 12 weeks after randomization ]
        Treatment group comparisons of the proportion of subjects with improvement in all outcome measures (CISS, NPC, PFV) at the 12 week visit using logistic regresion, adjusting for baseline ccovariates.
      • Treatment comparisons of successful treatment of CI based on objective measures [ Time Frame: 12-weeks after randomization ]
        Treatment comparisons of the proportion of subjects who are successfully treated for CI based on objective measures (NPC, PFV) at the 12-week visit using logistic regression analysis, adjusting for baseline covariates.
      • Treatment comparisons of successful treatment of CI based on symptoms [ Time Frame: 12 weeks after randomization ]
        Treatment comparisons of the proportion of subjects who are successfully treated for CI based on the CI symptom survey (CISS) at the 12-week visit using logistic regression analysis, adjusting for baseline covariates.
      • Proportion of subjects with a CI recurrence after discontinuing treatment [ Time Frame: 6 months and 12 months after the 12-week visit ]
        An estimate and 95% confidence interval will be computed using the exact binomial method to determine the overall and treatment group proportion of subjects with a CI recurrence at the 6- and 12-month post-treatment exams.
      • Successful treatment of CI according to subgroup factors [ Time Frame: 12 weeks after randomization ]
        Exploratory analyses will be utilized to assess treatment group differences in success proportions within predefined subgroups according to baseline factors. Interpretation of subgroup analyses will depend on whether the group comparisons of CBT versus active NTP or CBT versus placebo therapy demonstrate a significant treatment group difference.
      • Evaluate successful treatment of CI on ADHD signs/symptoms [ Time Frame: 12 weeks after randomization ]
        The purpose of this objective is to determine if successful treatment of CI reduces the reported symptoms/signs of ADHD as measured by the SWAN questionnaire. An analysis of covariance (ANCOVA) will be performed to compare mean scores at 12-weeks for those who meet success criteria versus those who do not at the outcome exam, adjusting for baseline scores.
      • Evaluate treatment group differences in ADHD signs/symptoms [ Time Frame: 12 weeks after randomization ]

        The purpose of this objective will be to perform a treatment comparison of the 12-week symptoms/signs of ADHD as measured by the SWAN questionnaire.

        An analysis of covariance (ANCOVA) will be performed to compare mean scores at 12-weeks by treatment group, adjusting for baseline scores. If there is a statistically significant treatment effect (F-test, p < 0.05), the Tukey-Kramer procedure for multiple pair-wise comparisons will be employed to perform the treatment group comparisons.



      Information By: Jaeb Center for Health Research

      Dates:
      Date Received: January 19, 2012
      Date Started: June 2012
      Date Completion:
      Last Updated: April 11, 2017
      Last Verified: April 2017