Binocular vision refers to the way the two eyes work together was a team. Many concussion patients develop various binocular vision problems. The most common is convergence insufficiency, which is successfully treated with vision therapy. Special lenses called prism lenses may be used instead of or in conjunction with vision therapy.
Binocular vision and oculomotor disorders are present in a high number of concussion patients. In fact, these problems often go undiagnosed because many professionals that concussion patients encounter do not have the expertise to diagnose them.
Even many eye care professionals test only for visual acuity, which is inadequate for concussion patients. Additional tests need to be performed. At our clinic, for example, we test for eye alignment, near point of convergence, mergence amplitude and facility, accommodative amplitude and facility, and saccadic eye movement speed and accuracy.
In a recent study, Master and colleagues conducted a prospective, cross-sectional study of adolescents aged 11 to 17 years who were recruited from the Minds Matter Concussion Program at The Children's Hospital of Philadelphia. The researchers found that 68% of the concussion patients had one or more vision problems. The most common problems were:
• convergence insufficiency (47.2%);
• accommodative insufficiency (33.3%);
• saccadic dysfunction (30.5%);
• accommodative infacility (11.1%).
Even if a patient has 20/20 vision, the presence of one of these conditions means that the eyes don't work as a team and they don't focus and track properly. This has serious implications for patients who are in school because schoolwork is highly visual and is only becoming more so with the increased use of computer, tablets, smartphones, smart board and other technologies.
We have successfully treated numerous patients with binocular and oculomotor problems with vision therapy, specially designed lenses or a combination of both. This experience is echoed in the scientific literature. For example, a 2002 study by Kapoor and Ciuffreda in the journal, Current Treatment Options in Neurology, found that binocular vision problems such as problems of accommodation, vergence, version and other are amenable to optometric vision therapy:
Anomalies of accommodation, vergence, version, photosensitivity, and field of vision are amenable to noninvasive, rehabilitative interventions, such as vision therapy, which is rendered by optometrists and is described in this article. Further, vision therapy may be performed in isolation or in conjunction with the application of the following:
• Fusional prism spectacles (for diplopia)
• Tinted spectacles (for photosensitivity)
• Yoked prism spectacles (for visual-spatial hemispheric inattention, with or without a manifest visual field defect), as appropriate