Vision Therapy and PressVision
The Science Behind Vision Therapy
Vision occurs as collaboration between the eyes and the brain, informed by feedback from the rest of the body. The science of vision therapy is therefore rooted in the ability to guide an individual to make changes through feedback and awareness. As in any effective therapy, there must be a differential diagnostic process identifying which aspects of the visual system are mal-developed or in need of rehabilitation. Intervention can then be designed in accordance with generalized principles of therapy.
Vision Therapy Should Be Individualized and Customized
The science of therapy has established that to be maximally effective, the therapy should be individualized and customized to the needs of the patient. The vision therapy may be implemented by a trained therapist, but must be administered under the supervision and guidance of a knowledgeable Doctor of Optometry. The patient must internalize changes and understand that the visual system is modified therapeutically not by procedures done to the patient, but to the extent the patient is responsible for viewing differently.
Technology has greatly aided the science of optometric vision therapy but placing the patient in front a computer cannot substitute for active observation and interaction with a therapist. In the next section we review research on vision therapy, but there is one major study that is crucial in understanding the science of vision therapy.
The CITT, or Convergence Insufficiency Treatment Trial, is a multicenter study funded by the National Institutes of Health. It began in 1992, when I was part of the planning group that met at the SUNY College of Optometry, where I was Chief of the Vision Therapy Service. The original name of the study was CIRS, or Convergence Insufficiency and Reading Study. At that point had you asked eye doctors what the one condition was about which we could all agree, it would be CI. We knew its signs and symptoms, how to test for it, how to diagnose it, and how to treat it. Even in classic ophthalmology textbooks, the one condition for which “orthoptics”, a primitive form of vision therapy was best suited, was CI.
However, once the biostatisticians got involved the planning changed. The name of the group was changed to CITT because we had to prove the science behind what was already known. Gold standard scientific method involved prospective, masked, placebo controlled, double-blind, multi-center design.
To make a much longer story short, the group progressed in stages to publish the CISS, or Convergence Insufficiency Symptom Survey, to prove that pencil push-up therapy or base-in prism glasses used in isolation were not effective, and that home-alone therapy was equivalent to placebo therapy. This is where the science becomes pivotal. Anyone currently treating convergence insufficiency without the benefit of supplemental in-office procedures is essentially dispensing placebo therapy until proven otherwise. I am not making a value judgment here. I am only citing principles behind the science of vision therapy.
For further discussion related to these issues, please read an interview I conducted with FAQs, and download an Editorial published on the subject of the CITT and placebo effects.