Effectiveness of vergence/accommodative therapy for accommodative dysfunction in children with convergence insufficiency

Abstract

Purpose To determine the effectiveness of office‐based vergence/accommodative therapy for improving accommodative amplitude and accommodative facility in children with symptomatic convergence insufficiency and accommodative dysfunction. Methods We report changes in accommodative function following therapy among participants in the Convergence Insufficiency Treatment Trial – Attention and Reading Trial with decreased accommodative amplitude (115 participants in vergence/accommodative therapy; 65 in placebo therapy) or decreased accommodative facility (71 participants in vergence/accommodative therapy; 37 in placebo therapy) at baseline. The primary analysis compared mean change in amplitude and facility between the vergence/accommodative and placebo therapy groups using analyses of variance models after 4, 8, 12 and 16 weeks of treatment. The proportions of participants with normal amplitude and facility at each time point were calculated. The average rate of change in amplitude and facility from baseline to week 4, and from weeks 4 to 16, were determined in the vergence/accommodative therapy group. Results From baseline to 16 weeks, the mean improvement in amplitude was 8.6 dioptres (D) and 5.2 D in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 3.5 D, 95% confidence interval (CI): 1.5 to 5.5 D; p = 0.01). The mean improvement in facility was 13.5 cycles per minute (cpm) and 7.6 cpm in the vergence/accommodative and placebo therapy groups, respectively (mean difference = 5.8 cpm, 95% CI: 3.8 to 7.9 cpm; p < 0.0001). Significantly greater proportions of participants treated with vergence/accommodative therapy achieved a normal amplitude (69% vs. 32%, difference = 37%, 95% CI: 22 to 51%; p < 0.0001) and facility (85% vs. 49%, difference = 36%, 95% CI: 18 to 55%; p < 0.0001) than those who received placebo therapy. In the vergence/accommodative therapy group, amplitude increased at an average rate of 1.5 D per week during the first 4 weeks (p < 0.0001), then slowed to 0.2 D per week (p = 0.002) from weeks 4 to 16. Similarly, facility increased at an average rate of 1.5 cpm per week during the first 4 weeks (p < 0.0001), then slowed to 0.6 cpm per week from weeks 4 to 16 (p < 0.0001). Conclusion Office‐based vergence/accommodative therapy is effective for improving accommodative function in children with symptomatic convergence insufficiency and coexisting accommodative dysfunction.

Investigation of the Relationship Between Subjective Symptoms of Visual Fatigue and Visual Functions

“…noted (Chen et al, 2021). F(+) means that the subjects had more difficulty in +2.00 D, whereas F(−) means that they experienced more difficulty in −2.00 D.…”

Does coexisting accommodative dysfunction impact clinical convergence measures, symptoms and treatment success for symptomatic convergence insufficiency in children?

“…Consistent with prior studies of symptoms in accommodative and convergence insufficiency, decreased amplitude of accommodation was defined as monocular amplitude of accommodation more than 2D below the minimum expected amplitude based on the participant's age (15 – ¼ age) 6,24,26,37,38 . Decreased accommodative facility was defined as <6 cycles per minute, which is 1 SD below the normative value of 11 cpm for school‐age children 6,7,39,40 …”

“…Mutual interactions between vergence and accommodation are well known, 1,2 and it is commonly accepted that patients often have concurrent dysfunction in both systems 3‐9 . Clinically, convergence insufficiency (CI) and accommodative dysfunction are associated with symptoms that occur when reading or performing other near work, such as blurred vision, headaches, asthenopia, frequent loss of place or poor concentration 3,4,10–23 …”

Virtual Reality-based Vision Therapy Versus OBVAT in the Treatment of Convergence Insufficiency, Accommodative Dysfunction: A Randomized Controlled Trial

“…The Convergence Insu ciency Treatment Trial (CITT) study group [14,15] reported that o ce-based vergence/accommodative therapy (OBVAT) was more effective than home-based push-up therapy, computer-based vision therapy, and o ce-based placebo therapy for improving binocular function in patients with convergence insu ciency. Other studies [16,17] also showed that OBVAT produced signi cant improvements in monocular accommodative amplitude and facility. Some studies [18,19] that investigated the effects of OBVAT on attention and reading in children with convergence insu ciency found that it could improve reading comprehension, reading speed, and academic behavior.…”