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Neurology & Stroke

Brief report Volume 12 Issue 6

Preliminary study for Neurovisual Assessment Model using Eye Tracking (NAMET) related to cognitive functions for TBI patients

Yoshida Daniela

University of São Paulo, Brazil

Correspondence: Daniela Yoshida, Professor at Faculdade Ratio; Faculdade Cruzeiro do Sul, Av Rogaciano Leite, 340. Fortaleza-CE, Brazil, Tel +5511997418987

Received: October 20, 2022 | Published: November 2, 2022

Citation: Daniela Y. Preliminary study for Neurovisual Assessment Model using Eye Tracking (NAMET) related to cognitive functions for TBI patients. J Neurol Stroke. 2022;12(6):180-182. DOI: 10.15406/jnsk.2022.12.00523

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Introduction: Traumatic brain injury can cause visual dysfunction (if not treated with visual therapy) and it can hinder a patient's rehabilitative progress. Screening for a Visual processing assessment to identify visual symptoms in TBI patients at the HCFMUSP Neurology Clinic. Previous literature presents common visual symptoms that were identified in these patients, such as:
  • visual field loss,
  • double vision,
  • posture and balance difficulties,
  • blurred vision,
  • attention and concentration problems
  • difficulties in near visual tasks,
  • headaches,
  • reading difficulties,
  • reading problems.
  • motor coordination problems,
  • difficulties locating objects accurately.
  • accommodative dysfunction
  • convergence insufficiency

This study presents a Neuro Visual assessment model for visual and cognitive rehabilitation following TBI and it can include Visual Acuity (VA) Visual Field, eye movements (Eye Tracking), Accommodation and Convergence.

Results: In the preliminary study, similarity was found between existing literature and visual dysfunctions from patients following TBI.

Conclusion: The assessment protocol following TBI can identify changes in saccadic eye movements, segments and their impacts on cognitive functions, sensory, motor and emotional systems. The treatment to improve visual dysfunctions can improve Reading problems; oculomotor, balance and binocular disorders using prisms, lenses and filters for both attention and concentration difficulties. Literature shows cases of improvement post-TBI visual symptoms using nonfunctional lenses, prisms, filters, binasal occlusions. Previous literature can found cases of improvement of depressive symptoms, aggressive behavior, self-confidence, self-esteem, posture and balance.

Keywords: visual disorders, visual impairment, severe TBI, neuro-optometry


Traumatic brain injury affects over 1 million people a year in Brazil and more than 1,700,000 people in the United States each year.1 Neurovisual Assessment Model using Eye Tracking (NAMET) identifies how visual information is processed in the brain. The Neurovisual Assessment Model is an important tool to identify symptoms or visual signs such as visual field loss, double vision, difficulties in posture and balance, blurred vision, difficulty maintaining attention and concentration on near visual tasks, headaches, reading difficulties, motor coordination problems, difficulties in locating objects accurately.

These neurovisual signs and symptoms cause a negative impact for TBI patients´ quality of life and also in patient's visual perception and their mood.2–8


To standardize NAMET for TBI patients and a secondary objective is to review the literature about visual symptoms for TBI patients at cognitive rehabilitation process to compare with actual evaluated patients.


Longitudinal study evaluated 10 TBI patients at cognitive rehabilitation stage to assess some visual functions. Analysis of the data available from June 2017 to December 2019 was performed. All information used to analyze post TBI patients in Brazil are from ICHCSP (Central Institute from Hospital das Clinicas in São Paulo). All excluded patients were those who suffered “eye trauma or have any patologic eye condition," considering these injuries to be less specific to TBI.

Neuro Visual Assessment Model for visual and Neuro Cognitive Rehabilitation following TBI can include:
  • Visual Acuity (VA)2,4,9
  • Visual Field,4,5,8
  • Oculomotricity (Eye Movements with Eye Tracking),5,10–13
  • Accommodation14–20
  • Convergence,14,21
  • Pupillary reflex,4,22–26

The Visual Acuity Test was performed at a distance of 1 meter and at a near distance of at least 30 cm using a low vision table called ETDRS and LEA TEST and Rosenbaum Near Vision Card (Near Chart). Damato's Test, Confrontation Test and Funcional Visual Campimetry were used to evaluate Visual Field Function.11,28

In the evaluation of Smooth Pursuit (or just Pursuit - class of rather slow eye movements that minimizes retinal target motion) it suggested to use eye tracking or NSUCO Test. Accommodation was measured using the Near Point of Accommodation (NPA) and Convergence test, evaluated by the Near Point of Convergence (PPC) test.14,21

Image 1 Eye tracking Device: Neurokinects.


NAMET evaluated alterations in eye movements (saccadic, smooth pursuits and fixation) not visible in subjective tests without the use of the Eye Tracking Device but it was not able to use eye tracking with severe TBI patients.

Post-TBI visual symptoms:

Binocular Visual Deficit (80%)

Photophobia (75%)

Accommodation and Convergence Problems (70%)

Diplopia (50%)

Reading Deficit (50%)

Oculomotor Deficits (80%)

Visual Field Loss (20%)


In some cases, visual rehabilitation improves cognitive rehabilitation (with a transdisciplinary team) improving visual acuity, using prisms, lenses and filters, improving the patient’s reading time, oculomotricity, balance, posture performance and proprioception for visual dysfunctions after TBI. Patients can identify the changes in saccadic eye movements, smooth pursuits and their impacts on cognitive functions, sensory, motor and emotional systems.

Treatment for visual dysfunctions can improve Reading Problems; oculomotor dysfunctions, balance and binocular disorders using prisms, lenses and filters also for attention and concentration difficulties.18,29–33  Literature shows cases of improvement post-TBI visual symptoms using nonfunctional lenses, prisms, filters, binasal occlusions, cases of improvement of depressive symptoms, aggressive behavior, self-confidence, self-esteem, posture and balance.4,13,31,32,34–36



Conflicts of interest

The author declares no conflicts of interest.


  1. CDC. Centers for Disease Control and Prevention. National Center for Health Statistics: Mortality Data on CDC WONDER. 2022.
  2. Chnag A, Cohne A, Kapoor N. Top-down Visual Framework for Optometric Vision Therapy for those with Traumatic Brain Injury. APA Psycnet. 2013;1(2):48–53.
  3. Ciuffreda KJ. Ludlan D, Yadav NK. Conceptual Model of optometric Vision Care in Mild Traumatic Brain Injury. J Behav Optom. 2011;22:10–12.
  4. Mather. The Visual Cortex.
  5. Padula william C. O.d. Guilford, Conn. Neuro- Optometric Rehabilitation For Persons with TBI or CV. Journal of Optometric Vision Development. p.4–8.
  6. Tong D, Zink C.  Vision Dyfunctions Secondary to a Motor Vehicle Accident : A case Report. Optom Vis Dev. 2010;41(3):158–168.
  7. Padula W. Visual Evoked Potencials (VEP) evaluating treatments for post trauma vision syndrome (PTVS) in patients with traumatic brain injuries (TBI). Br Inj. 1994;8(2):125–133.
  8. Rolfs M. Microsaccades: small steps on a long way. Vision Res. 2009;49(20):2415– 2441.
  9. Goss DA. Ocular Accommodation, Convergence, and Fixation Disparity: a Manual of Clinical Analysis. Boston: Butterworth – Heinemann. 1995.
  10. Rouse Michael, Scheiman Mitchell. Optometric Management of Learning-Related Vision Problems. Second Edition. Optometric Extension Program Foundation. Santa Ana CA: 2013.
  11. Berens C, Sells SB.Experimental studies of fatigue of accommodation. Am J Ophthalmol. 1950;33(1):47–58.
  12. Otero-Millan J, Macknik SL, Martinez-Conde S. Fixational Eye movements and binocular vision. Front Integr Neurosc. 2014;8:52.
  13. Scheiman M, Wick B. Clinical Management of Binocular Vision: Heterophoric, Accommodative and Eye Movement Disorders. 2nd edn. Philadelphia: Lippincott Willians and Wilkins, 2002, pp. 3–52.
  14. Abraham NG, Srinivasan K, Thomas J. Normative data for near point of convergence, accommodation, and phoria”. Oman J Ophthalmol. 2015;8(1):14–18.
  15. Cohen AH. Optometric Management of binocular dysfunctions secondary to head trauma: case reports. J Am Optom Assoc. 1992;63(8):569–575.
  16. Cohen AH, Rein LD. The effect of head trauma on the visual system: the doctor of optometry as a member of the rehabilitation team. J Am Optom Assoc. 1992;63(8):530–536.
  17. Galetta KM, Barrett J, Allen M, et al. The King-Devick test as a determinant of head trauma and concussion in boxers and MMA fighters. Neurology. 2011;76(17):1456–1462. 
  18. Digre K. Principles and Techniques of Examination of the Pupils, Accommodation, and Lacrimation. In: Walsh and Hoyt’s Clinical Neuro-Ophthalmology. Philadelphia: Lippincott Williams & Wilkins. 2005, pp. 727-731.
  19. Stidwill D, Letcher R. Normal Binocular Vision: Theory, Investigation and Practical Aspects. Malden: Blackwell Publishing, 2011.
  20. Goodrich GL. Mechanisms of TBI and Visual Consequences in Military an Veteran Populations. Optometry and Vision Science. 2013;90(2):105–112.
  21. Adler PM, Cregg M, Viollier AJ. Influence of target type and RAF rule on the measurement of near point of convergence. Ophthalmic and Physiological Optics. 2007;27:22–30.
  22. Garzia RP. Vision and Reading II. Journal of Optometric Vision Development. 1996;194(25):4–26.
  23. Koller HP. How does vision affect learning? J Ophthalmic Nurs Technol. 1997;16(1):7–11.
  24. Stephens G, Jones R.Horizontal fusional amplitudes after adaptation to prism. Ophthalmic Physiological Opt. 1990;10(1):25–28. 
  25. Fletcher R, Stidwill D. The binocular integrative action of the visual system. Normal Binocular Vision: theory, investigation and practical aspects. 2011 Blackwell Publishing Lt.
  26. Hering E. The theory of binocular vision. New York: Plenum Press, 1868.
  27. Press Leonard. Applied concepts vision therapy. 2nd edn. Optometric Extension Program Foundation. Santa Ana CA: 2008.
  28. Benedict PA, Baner NV, Harrold GK, et al. Gender and age predict outcomes of cognitive, balance and vision testing in a multidisciplinary concussion center. J Neurol Sci. 2015;353(1-2):111–115.
  29. Fray KJ. Fusional amplitudes: exploring where fusion falters. Am Orthop J. 2013;63:41–54. 
  30. Hillman EJ, Bloomberg JJ, McDonald PV, et al. Dynamic visual acuity while walking in normals and labyrinthine-deficient patients. J Vestib Res. 1999;9(1):49–57.
  31. Silva TH, Masetti T, Silva TD. et al. Influence of severity of traumatic brain injury at hospital admission on clinical outcomes. Fisioter Pesqui. 2018;25(1):3–8.   
  32. Santos JC. Traumatismo cranioencefálico no Brasil: análise epidemiológica. Rev Cient Esc Estadual Saúde Pública Goiás "Candido Santiago". 2020;6(3):e6000014.
  33. Sherrington’S The integrative action of the nervous system. Milford: Oxford University Press, 1906.
  34. Pádua CS, Scherer TAP, Prado PR, et al. Perfil epidemiológico de pacientes com traumatismo crânio-encefálico (tce) de uma unidade de terapia intensiva na cidade de rio branco-ac, amazônia ocidental. South American Journal of Basic Education, Technical and Technological. 2018;5(1).
  35. Datasus.
  36. Wolfe J, Kleunder KL, Levi DM. Sensation & Perception. 3rd edn,  Sunderland: Sinauer Associates. 2012.
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