Vision therapy: Reading scores improve but no more effective between therapy and placebo groups

A common childhood vision disorder, convergence insufficiency (CI) looked up after weeks of vision therapy but its impact on children's reading test scores shouldn't be overblown.

That's the conclusion of the study, "Effect of Vergence/Accommodative Therapy on Reading in Children with Convergence Insufficiency: A Randomized Clinical Trial," published in November 2019 by Optometry and Vision Science. In the clinical trial, 310 children ages 9 to 14 were assigned to either of two groups for 16 weeks of treatment: a group providing office-based therapy for vergence and accommodation or a group for office-based placebo therapy. The study measured various outcomes including reading comprehension, word identification, reading fluency and listening comprehension among others.

The study, conducted by the CITT-ART Investigator Group, follows an earlier trial, Convergence Insufficiency Treatment Trial (CITT), published in Ophthalmology in 2008.

Its key finding:

Although all students showed an improvement in reading, no significant statistical difference was found between the two groups when it came to reading comprehension (therapy vs. placebo was a -0.12-point difference). That was true also for the other, secondary outcomes measured.

"While in-office vision therapy can improve visual function for children with CI, this trial indicates that clinicians should not suggest that it will lead to increased reading performance," lead study author Mitchell Scheiman, O.D., Ph.D., Salus University, Pennsylvania College of Optometry, said in a news release issued by the National Eye Institute, which funded the trial.

Doctors of optometry can help patients reach their potential

Mary Gregory, O.D., who practices in Monticello, Minnesota, called the study's findings "exciting" for building on doctors' knowledge base and reinforcing findings in past studies. Dr. Gregory, who received the 2014 Dr. W. David Sullins Jr. InfantSEE^® Award for outstanding public service, operates a clinic where she provides vision rehabilitation for adults and children. 

"In the end, the significance of the study for doctors is that you cannot say that following 16 weeks of accommodative/vergence therapy for a symptomatic CI patient, that you will improve reading comprehension of a child more than the child who does 16 weeks of placebo therapy," Dr. Gregory says. "But this study provides a reminder to us that reading is a very complex process that involves vision as only one piece of the puzzle. While poor visual skills and processing certainly can negatively impact a reader, it is not the only skill needed to be successful."

She adds: "Symptomatic readers with poor visual skills and poor visual processing should still be treated to allow the child to reach their full potential. We are not trying to cure a learning disability or ADHD with vision therapy, but instead we remove a condition impacting the child's ability to reach their potential."