Convergence Insufficiency Neuro-mechanism in Adult Population Study Randomized Clinical Trial: Clinical Outcome Results

Abstract

Significance: These data confirm the effectiveness of office-based vergence/accommodative therapy for improving the near point of convergence and positive fusional vergence in young adults with symptomatic convergence insufficiency within a double-masked longitudinal randomized clinical trial.

Purpose: This study aimed to report changes in clinical signs and symptoms of convergence insufficiency from a randomized clinical trial evaluating the effectiveness of office-based vergence/accommodative therapy for young adults with symptomatic convergence insufficiency.

Methods: In this double-masked, randomized clinical trial, convergence insufficiency patients (n = 50; average age, 21 ± 3 years; range, 18 to 32 years) were randomized to either office-based vergence/accommodative therapy or office-based placebo therapy. Improvements in (1) near point of convergence, (2) positive fusional vergence, and (3) self-reported symptoms (Convergence Insufficiency Symptom Survey [CISS] score) were evaluated after twelve 1-hour sessions of treatment within the office comparing the results from the vergence/accommodative therapy and the placebo therapy groups.

Results: The mean near point of convergence improved by 6.0 and 3.1 cm in the vergence/accommodative and placebo therapy groups, respectively (mean difference of -2.9 cm; 95% confidence interval [CI], -4.6 to -1.0 cm; P < .01). The mean positive fusional vergence increased by 17.3 and 7.4Δ in the vergence/accommodative and placebo therapy groups, respectively (mean difference of 9.9Δ; 95% CI, 4.9 to 16.0Δ; P < .001). The mean CISS score improved by 12.4 and 10.1 points in the vergence/accommodative and placebo therapy groups, respectively (mean difference of 2.3 points; 95% CI, -8.3 to +4.6 points; P = .56).

Conclusions: Our results demonstrate that office-based vergence/accommodative therapy is effective for improving the near point of convergence and positive fusional vergence in young adults with symptomatic convergence insufficiency. However, given that both treatment groups had a similar reduction in self-reported symptoms, we recommend that the CISS be revised if it is to be used as an outcome measure in future studies of convergence insufficiency.

Figures

Figure 1.

CONSORT flow chart of study.