Purpose: To compare base-in prism reading glasses with placebo reading glasses for the treatment of symptomatic convergence insufficiency (CI) in children aged 9 to <18 years. Methods: In a randomised clinical trial, 72 children aged 9 to <18 years with symptomatic CI were assigned to either base-in prism glasses or placebo reading glasses. Symptom level, measured with a quantitative symptom questionnaire (CI Symptom Survey-V15), was the primary outcome measure. Near point of convergence and positive fusional vergence at near were secondary outcomes.
Results: The mean (SD) CI Symptom Survey score decreased (that is, less symptomatic) in both groups (base-in prism glasses from 31.6 (10.4) to 16.5 (9.2); placebo glasses from 28.4 (8.8) to 17.5 (12.3)). The change in the CI Symptom Survey scores (p = 0.33), near point of convergence (p = 0.91), and positive fusional vergence (p = 0.59) were not significantly different between the two groups after 6 weeks of wearing glasses.
Conclusions: Base-in prism reading glasses were found to be no more effective in alleviating symptoms, improving the near point of convergence, or improving positive fusional vergence at near than placebo reading glasses for the treatment of children aged 9 to <18 years with symptomatic CI. M Scheiman1, S Cotter2, M Rouse2, G L Mitchell3, M Kulp3, J Cooper4, E Borsting2, and the Convergence Insufficiency Treatment Trial (CITT) Study Group* + Author Affiliations 1Eye Institute, Pennsylvania College of Optometry, Philadelphia, PA, USA 2Southern California College of Optometry, Fullerton, CA, USA 3Optometry Coordinating Center, The Ohio State University, Columbus, OH, USA 4College of Optometry, State University of New York, New York, NY, USA Correspondence to: Professor M Scheiman Eye Institute, Pennsylvania College of Optometry, 1200 West Godfrey Ave, Philadelphia, PA 19141, USA; email@example.com Accepted 1 March 2005