Office-based vergence and accommodative therapy can enact significant changes in clinical signs and symptoms in young patients with symptomatic convergence insufficiency (CI) but may miss the mark where it counts, according to new research.
One study evaluated vision therapy in 12, one-hour sessions on 14 males (age=21±3.6 years). The study found improvements in near point of convergence, positive fusional vergence at near, CI symptom survey and 5° disparity convergence peak velocity measurements post-vision therapy. “The ones that participated in office-based vergence and accommodative therapy improved to the point where they were healthy controls,” Tara Alvarez, PhD, professor of biomedical engineering at the New Jersey Institute of Technology noted during her presentation at the recent American Academy of Optometry annual meeting in Orlando. Office-based vergence and accommodative therapy significantly improved functional activity in the frontal eye fields, supplementary eye fields, parietal eye fields and especially the ocularmotor vermis.
Dr. Alvarez concluded that understanding the underlying neural basis of vision therapy has the potential to lead to personalized and more effective therapeutic interventions to improve binocular coordination in CI patients.1
However, another group of researchers found that, while office-based vergence/accommodative therapy improves near point of convergence, it does not improve reading performance when measured with standardized metrics. The Convergence Insufficiency Treatment Trial–Attention & Reading Trial (CITT-ART) investigator group reported changes in CI clinical signs and symptoms in 311 symptomatic children between the ages of 9 and 14. Participants were randomly assigned to either 16 weeks of office-based vergence/accommodative therapy or placebo therapy. The study found improvements in mean near point of convergence and positive fusional vergence. Researchers suggested clinicians avoid using the self-reported CI symptom score alone as a measure of successful treatment. 2
However, the CITT-ART investigator group also measured change in reading comprehension with the reading comprehension subtest of the Wechsler Individual Achievement Test after the 16-week treatment period. Their second study assessed 310 children for word identification, reading fluency, listening comprehension, comprehension of extended text and reading comprehension. The researchers found no statistically significant differences for any of these measures in the treatment group.3
1. Alvarez TA, Scheiman MM, Morales C, et al. CINAPS - Convergence Insufficiency Neuro-Mechanism in Adult Population Study: effect of vision therapy on clinical, objective eye movement and fMRI measures. American Academy of Opotometry 2019; Orlando, FL.
2. CITT-ART Investigator Group. Treatment of symptomatic convergence insufficiency in children enrolled in the convergence insufficiency treatment trial–attention & reading trial. Optom Vis Sci. October 23, 2019. [Epub ahead of print].
3. CITT-ART Investigator Group. Effect of vergence/accommodative therapy on reading in children with convergence insufficiency. Optom Vis Sci. October 23, 2019. [Epub ahead of print].