Rehabilitation Therapists

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Vision Therapy

Recently, Behavioural Optometrist Paul Graham of Harmony Vision provided a presentation to our Physiotherapists and Occupational Therapists on vision therapy. We were very excited to welcome Paul Graham to the Neuro Junction clinic to discuss vision therapy so that we could better understand his company’s management of binocular vision disorders.

Humans have binocular vision; it is what allows us to be able to see the world as a three-dimensional image. This is a crucial skill as it allows us to identify obstacles such as a trip hazard when walking to ensure we appropriately navigate it with precision.  For this to effectively work, we must have extremely tight control over how our eyes move and their alignment or otherwise we can have what is called a binocular vision disorder. This is commonly seen in neurological populations such as stroke, multiple sclerosis, Parkinson’s disease, traumatic brain injury, ataxia, and concussion.

Common symptoms of binocular disorders include:

  • Double vision

  • Headaches

  • Problems focusing and concentrating

  • Difficulty reading

  • Vertigo

  • Eye strain and sore eyes

  • Fatigue

  • Blurred vision

  • Motion sickness

  • Anxiety


The presentation was focused on Convergency insufficiency as this is a common binocular disorder that is seen within neurological conditions that attend Neuro junction and can respond to therapeutic intervention (i.e. vision therapy). For instance, convergency insufficiency is commonly seen post-concussion and can cause clients to have many of the symptoms listed above. Optometrists, physiotherapists, and OTs assess convergence insufficiency through the use of Near Point Convergence Test (NPCT).

NPCT is a simple test where a target, such as a small letter on a paddle pop, is slowly brought close to the persons tip of their nose until the person complains of double vision (diplopia) or there is an outward movement of one of the persons eyes (see picture below). The distance is measured from the face to the target and this is called the near point convergence (NPC) and it can be compared to well defined normative values. If someone falls out of the normative value, they may have a convergence insufficiency.

At Harmony vision, their Behavioural Optometrists and Vision Therapists treat binocular vision disorders through the prescription of reading glasses and vision therapy. Harmony vision specialise in functional vision therapy which means that they complete convergence insufficiency exercises within a meaningful context to the client. They delve into what causes their clients symptoms and then they can create an individualised programme that the client participates in for a period of time to improve the noted problem areas.

At Neuro Junction, our Physiotherapists can assess near point convergence alongside assessments of your cervical spine, vestibular systems, and coordination to holistically understand your symptoms in relation to your condition. Your physiotherapist may recommend you are referred to Harmony Vision to better understand your potential binocular vision and how it is impacting you.

References:

Alvarez, T. L., Scheiman, M., Morales, C., Gohel, S., Sangoi, A., Santos, E. M., Yaramothu, C., d'Antonio-Bertagnolli, J. V., Li, X., & Biswal, B. B. (2021). Underlying neurological mechanisms associated with symptomatic convergence insufficiency. Scientific reports11(1), 6545. https://doi.org/10.1038/s41598-021-86171-9

Alvarez, T. L., Kim, E. H., Vicci, V. R., Dhar, S. K., Biswal, B. B., & Barrett, A. M. (2012). Concurrent vision dysfunctions in convergence insufficiency with traumatic brain injury. Optometry and vision science : official publication of the American Academy of Optometry89(12), 1740–1751. https://doi.org/10.1097/OPX.0b013e3182772dce

Brune, A. J., & Gold, D. R. (2019). Acute Visual Disorders-What Should the Neurologist Know?. Seminars in neurology39(1), 53–60. https://doi.org/10.1055/s-0038-1677007

Gil-Casas, A., Piñero-Llorens, D. P., & Molina-Martin, A. (2021). Binocular Vision in Patients with Multiple Sclerosis. Clinical optometry13, 39–49. https://doi.org/10.2147/OPTO.S286862

Heick, J. D., & Bay, C. (2021). Determining Near Point of Convergence: Exploring a Component of the Vestibular/Ocular Motor Screen Comparing Varied Target Sizes. International journal of sports physical therapy16(1), 21–30. https://doi.org/10.26603/001c.18867

Śmiłowska, K., Wowra, B., & Sławek, J. (2020). Double vision in Parkinson's Disease: a systematic review. Neurologia i neurochirurgia polska54(6), 502–507. https://doi.org/10.5603/PJNNS.a2020.0092

Jessica Nienhuis