Pritam Dutta, M.Optom

Lecturer, Ridley College of Optometry, Optometrist, Chandraprabha Eye Hospital Jorhat, Assam

 

Traumatic Brain Injury (TBI) is defined, “as an alteration in brain function, or other evidence of  brain pathology, caused by an external force”1. The mode of TBI can be either due to falls, assaults, road traffic accidents, pedestrian accidents, sports-related, industrial and workplace-related accidents2. Among all, mild TBI accounts for 75% alone3. The American Congress of Rehabilitation Medicine (ACRM) defined mild TBI as “traumatically induced physiological disruption of brain function, as manifested by at least one of the following: any period of loss of consciousness, any loss of memory for events immediately before or after the accident, an alteration in the mental state at the time of the accident (disoriented or confused), focal neurological deficit that may or may not be transient”.

There occurs a cellular and sub cellular level damage in mild TBI without the involvement of any haemorrhage or any changes detectable in imaging techniques4. Visual symptoms following TBI include near vision problems with prolonged reading, glare, photosensitivity, and difficulty maintaining fusion5. The most common symptoms an individual develops following mild TBI are headache, dizziness, fatigue, irritability, insomnia, difficulty concentrating, memory problems, and/or intolerance of stress6. Several studies have found convergence insufficiency, accommodative dysfunction, and oculomotor problems to be the commonest among patients following mild TBI7 (see Table 1). It is reported that there occurs a diffuse and multiple axonal damages which in turn causes disruption of accommodation and vergence neural nerve fibers leading to certain dysfunctions8. The saccade and pursuit share a common premotor neural pathway which contains neurons of inhibitory omnipause and neurons of pursuits and saccades in the paramedian pontine reticular formation (PPRF) and any lesions following TBI to this area leads to oculomotor dysfunction9. These alterations in the accommodation, vergence and versions also have an impact on the academic performances of adult/children, leading to lack of concentration, difficulty performing near tasks, and asthenopia which results in achieving lower grade points when compared to a non-TBI child10,11.

Common ocular conditions Findings in mild TBI
Accommodation Reduced amplitude, time constant, peak accommodative velocity12
Vergence Reduced convergence amplitude and poor fusional vergence13
Oculomotor based reading dysfunction Reduced reading speed, poor comprehension, deficit in saccades and pursuits14,15
Photosensitivity Found in a larger prevalence of mild TBI individuals due to poor pupillary dynamics16
Pupillary response Delayed pupillary latencies and velocities17
Visual memory Impaired18
Vestibular dysfunction Associated with symptoms such as blurred vision, dizziness, nausea etc. due to various neurometabolic changes occurring following a mild TBI19
Visual field

Scattered, restricted; might be homonymous 22

Table 1: Common ocular findings in mild TBI.

 

A thorough ocular examination including the tests for binocular vision, eye movements, visual processing and visual efficiency would provide an estimation of the underlying abnormalities in mild TBI individuals. Therefore, eye care professionals play a crucial role in diagnosing and treating these visual consequences, working as an integrated team in a hospital or an individual set up. The Neuro-optometric based vision therapy and other treatment modalities (see Table 2) along with a proper referral for managing the associated non-ocular based problem would significantly make a difference in improving the quality of life in those patients.

 

Conditions Management options
Accommodation Accommodative training (vision therapy)15
Vergence Vergence training (vision therapy)15
Reading deficits Oculomotor rehabilitation15
Photosensitivity Tinted glass20
Vestibular dysfunction Vestibular therapy20,21
Visual field Prisms and visual scanning20,21

Table 2: Management options for associated conditions following mild TBI.


 

References:

  1. Thomas R.Frieden FSC. Report to Congress on Traumatic Brain Injury in the United States : Understanding the Public Health Problem among Current and Former Military Personnel.; 2013.
  2. Reznik, J. E., Biros, E., Marshall, R., et.al. (2014). Prevalence and risk-factors of neurogenic heterotopic ossification in traumatic spinal cord and traumatic brain injured patients admitted to specialised units in Australia. Journal of musculoskeletal & neuronal interactions14(1), 19–28.
  3. Dewan, M. C., Rattani, A., Gupta, S.et. al. (2018). Estimating the global incidence of traumatic brain injury, Journal of Neurosurgery JNS130(4), 1080-1097.
  4. Barnett, B. P., & Singman, E. L. (2015). Vision concerns after mild traumatic brain injury. Current treatment options in neurology, 17(2), 329. https://doi.org/10.1007/s11940-014-0329-y
  5. Padula W V, Simmons-grab D, Cannelongo J, et al. Visual Dysfunction Following a Neurological Event. NORA. 1995
  6. Barlow, K. M. (2016). Postconcussion Syndrome: A Review. Journal of Child Neurology31(1), 57–67. https://doi.org/10.1177/0883073814543305
  7. Matuseviciene, G., Johansson, J., Möller, M., et al. (2018).Longitudinal changes in oculomotor function in young adults with mild traumatic brain injury in Sweden: an exploratory prospective observational study. BMJ open8(2), e018734. https://doi.org/10.1136/bmjopen-2017-018734
  8. Searle, A., & Rowe, F. J. (2016). Vergence Neural Pathways: A Systematic Narrative Literature Review. Neuro-ophthalmology (Aeolus Press)40(5), 209–218. https://doi.org/10.1080/01658107.2016.1217028
  9. Ciuffreda, K. J., Kapoor, N., Rutner, D., et.al. (2007). Occurrence of oculomotor dysfunctions in acquired brain injury: a retrospective analysis. Optometry (St. Louis, Mo.)78(4), 155–161. https://doi.org/10.1016/j.optm.2006.11.011
  10. Russell, K., Hutchison, M. G., Selci, E., et.al. (2016). Academic Outcomes in High-School Students after a Concussion: A Retrospective Population-Based Analysis. PloS one11(10), e0165116. https://doi.org/10.1371/journal.pone.0165116
  11. Swanson, M. W., Weise, K. K., Dreer, L. E., et.al. (2017). Academic Difficulty and Vision Symptoms in Children with Concussion. Optometry and vision science : official publication of the American Academy of Optometry94(1), 60–67. https://doi.org/10.1097/OPX.0000000000000977
  12. Green, W., Ciuffreda, K. J., Thiagarajan, P., et.al. (2010). Accommodation in mild traumatic brain injury. Journal of rehabilitation research and development47(3), 183–199. https://doi.org/10.1682/jrrd.2009.04.0041
  13. Szymanowicz, D., Ciuffreda, K. J., Thiagarajan, P., et.al. (2012). Vergence in mild traumatic brain injury: a pilot study. Journal of rehabilitation research and development49(7), 1083–1100. https://doi.org/10.1682/jrrd.2010.07.0129
  14. Capó-Aponte, J. E., Urosevich, T. G., Temme, L. A., et. al. (2012). Visual dysfunctions and symptoms during the subacute stage of blast-induced mild traumatic brain injury. Military medicine177(7), 804–813. https://doi.org/10.7205/milmed-d-12-00061
  15. Thiagarajan, P., Ciuffreda, K. J., Capo-Aponte, J. E., et.al. (2014). Oculomotor neurorehabilitation for reading in mild traumatic brain injury (mTBI): an integrative approach. NeuroRehabilitation34(1), 129–146. https://doi.org/10.3233/NRE-131025
  16. Truong, J. Q., & Ciuffreda, K. J. (2016). Objective Pupillary Correlates of Photosensitivity in the Normal and Mild Traumatic Brain Injury Populations. Military medicine181(10), 1382–1390. https://doi.org/10.7205/MILMED-D-15-00587
  17. Ciuffreda, K. J., Joshi, N. R., & Truong, J. Q. (2017). Understanding the effects of mild traumatic brain injury on the pupillary light reflex. Concussion (London, England)2(3), CNC36. https://doi.org/10.2217/cnc-2016-0029
  18. Arciniega, H., Kilgore-Gomez, A., Harris, A., et.al. (2019). Visual working memory deficits in undergraduates with a history of mild traumatic brain injury. Attention, perception & psychophysics81(8), 2597–2603. https://doi.org/10.3758/s13414-019-01774-9
  19. Gurley, J. M., Hujsak, B. D., & Kelly, J. L. (2013). Vestibular rehabilitation following mild traumatic brain injury. NeuroRehabilitation32(3), 519–528. https://doi.org/10.3233/NRE-130874
  20. Ciuffreda, Kenneth & Diana, O & Ludlam, Diana. (2011). Conceptual Model of Optometric Vision Care in Mild Traumatic Brain Injury. The Journal of Behavioral Optometry. 22.
  21. Ciuffreda, K.J., Ludlam, D.P., & Kapoor, N. (2009). Clinical Oculomotor Training in Traumatic Brain Injury.
  22. Suchoff, I. B., Kapoor, N., Ciuffreda, K. J., et.al. (2008). The frequency of occurrence, types, and characteristics of visual field defects in acquired brain injury: a retrospective analysis. Optometry (St. Louis, Mo.)79(5), 259–265. https://doi.org/10.1016/j.optm.2007.10.012