Purchase this article with an account.
M. T. Kulp, G. L. Mitchell, E. Borsting, M. Scheiman, S. Cotter, M. Rouse, S. Tamkins, B. G. Mohney, A. Toole, CITT Study Group; Effectiveness of Placebo Therapy for Maintaining Masking in a Clinical Trial of Vergence/Accommodative Therapy. Invest. Ophthalmol. Vis. Sci. 2009;50(13):1997.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine if demographic variables affected masking of subjects in the Convergence Insufficiency Treatment Trial (CITT) and whether perception of assigned treatment group was associated with treatment outcome or adherence to treatment. We also evaluated the effectiveness of the CITT placebo therapy program in maintaining masking of patients randomized to the office-based treatment arms.
Patients (n=221, ages 9 to 17 years) were randomized to one of 4 treatment groups; 2 of which were office-based and masked to treatment (n=114). The placebo therapy program was designed to appear like real vergence/accommodative therapy, without stimulating vergence, accommodation, or fine saccades (beyond levels of daily visual activities). After treatment, patients in the office-based groups were asked if they thought they received real or placebo therapy and how confident they were in their answer.
Ninety-three percent of patients assigned to real therapy and 85% assigned to placebo therapy thought they were in the real therapy group (p=0.17). No significant differences were found between the two groups in adherence (p≥0.22 for all comparisons). The percentage of patients who thought they were assigned to real therapy did not differ by age, gender, race or ethnicity (p > 0.30 for all comparisons). No association was found between patients’ perception of group assignment and symptoms or signs at outcome (p≥0.38 for all comparisons).
The CITT placebo therapy program was effective in maintaining patient masking in this study and, therefore, may potentially be used in future clinical trials using vergence/accommodative therapy. Masking was not affected by demographic variables. Perception of group assignment was not related to symptoms or signs at outcome.
Clinical Trial: :
This PDF is available to Subscribers Only