There is little doubt that yesterday’s news release from NIH will be promoted by critics of optometric vision therapy to fuel their bias against the field. Although I’m not certain of who selected the headline for the release, “Treatment for common vision disorder does not improve children’s reading skills”, it is clearly a misrepresentation of what the study concluded. What will get lost is the sub-headline of the release, which is the real story: “NIH-funded study finds therapy for convergence insufficiency is no better at improving reading than placebo.”
So clearly the study is not concluding that therapy for CI does not improve reading. It is simply saying that both the therapy group and the placebo group improved in reading, but not to a statistically significant degree. What is it about the placebo group that enabled it to perform so well?
In a guest editorial after the original CITT study was published in 2008, I noted that the procedures used in the placebo activities (see here) actually encompassed many visual attention and visual perceptual activities, a number of which could be expected to to improve visual processing abilities associated with reading readiness. As I wrote then, these include: 1) equalizing monocular skills through fixation training 2) equalizing monocular just noticeable differences with loose prism jumps 3) equalizing monocular pursuits. Many of the other placebo procedures involved sustained visual attention under binocular conditions, and several involve looking for changes in spatial localization with low power lateral yoked prisms. It is not unreasonable to propose that CI is more than a primary eye muscle imbalance or a secondary accommodative problem, and is rooted in the inability to select an area of visual space for sustained visual attention at near.
What should grab headlines is that CITT-ART shows the complexity of reading, and how visual activities beyond classical vergence and accommodation orthoptic-type activities can improve reading readiness. The placebo activities in the study were designed with only one goal in mind: to lack a direct stimulus to vergence or binocular accommodation. The fact that they had such a salient effect on a wide variety of symptoms related to reading contained in the CI Symptom Survey (CISS) such as concentration during reading, remembering what is read, instability of print, and loss of place, supports the fact that reading is a complex process that includes visual factors that may be more pertinent to reading readiness than accommodation and vergence.
As noted in a position paper of the American Academy of Optometry on Optometric Care of the Struggling Student: “Vision problems can affect students with learning disabilities, language-based dyslexia, or ADHD as well as students without these conditions. Students with learning, reading, or attention problems typically have several factors that impact school performance. Vision problems may be one of these factors and should be treated in these students. Treatment of the vision condition is not intended to cure the learning disability, ADHD, or dyslexia. Instead, the treatment is designed to remove obstacles to efficient learning.”
It is worth recalling the editorials published accompanying the original CITT papers in ophthalmology journals in 2005 and in 2008. These editorials noted that while the studies may be scientifically valid, they are not necessarily indicative of the way therapy is practiced in the real world – and caution should be exercised in accepting the CITT as supportive of optometric vision therapy versus “orthoptics”. Indeed, the CITT has had limited impact on the way those outside optometry have changed their modus operandi. Many insurance companies adopted arbitrary guidelines that followed the sentiment of the editorials rather than the science of CITT, and required patients to try home-alone therapy first despite lack of randomized clinical trials showing the efficacy of that approach. I doubt there will be any similar editorials of caution from non-optometrists about over-extrapolating the seemingly negative results of the new CITT-ART study, and noting why the placebo arm had such powerful results and its relationship to the way that optometric vision therapy is conducted in the real world. But there should be.
(See also CITT-ART – Part Two)