1. Visual and Perceptual Deficits After a Neurological Event
Stacy Krueger, OTR/L, C/NDT
2016

2. Why is Vision Important?
Vision plays a vital role in all activities of daily living
Visual deficits are often overlooked

3. Three Component Model of Vision
Visual Integrity
Visual Efficiency
Visual Information Processing

4. Visual Integrity Visual Acuity, Refraction, and Eye Heath
Visual Acuity (i.e., 20/20)
Numerator- testing distance at which the subject recognizes stimulus
Denominator- Distance at which the letter being viewed could be identified by a patient with normal visual acuity

5. Visual Integrity Visual Acuity, Refraction, and Eye Heath
Refraction- The optical system of the eye
Emmetropia (without refraction error)
Myopic (nearsighted)
Hyperopic (farsighted)
Astigmatism

6. Refraction Errors

7. Visual Integrity Visual Acuity, Refraction, and Eye Heath Eye Heath-
Anterior segment, lens, posterior segment, visual pathway

8. Eye Health Disorders Low Vision: 20/70 or worse with best correction
Anterior Segment Diseases
Ptosis, Inflammations, Corneal Scar

9. Eye Health Disorders
Diseases of the Lens
Cataracts

10. Vision with Cataracts

11. Eye Health Disorders Posterior Segment Diseases
Glaucoma, Diabetic Retinopathy, Age Related Macular Degeneration

12. Diabetic Retinopathy

13. Age Related Macular Degeneration
Leading cause of blindness in those older than 65 years
Dry Macular Degeneration- 20/20 to 20/400
Wet Macular Degeneration- worse than 20/400

14. Visual Pathways

15. Vision Changes after an Injury
The location of damage caused by a stroke or brain injury will determine the different visual changes.
Each eye receives some of the information from each half of the environment.
The information or image from each eye is combined, crosses over in the middle of the brain, and is then carried to the occipital lobes.
If you have a stroke on the right side of your brain, it primarily affects the vision on the left. A stroke on the left side of the brain affects the vision on the right.

16. Visual Field Cut (Hemianopsia)
Visual Field is everything you see when your both eyes are open.
Visual field cut (i.e., hemianopsia) is the inability to see part of the visual field
The most common loss of vision is the ability to see on one side (peripheral vision) or loss of half the visual field of each eye.
Visual field loss may take a long time to improve or may be permanent.

17. Visual Field Cuts

18. Visual Field Cuts

19. Visual Field Cuts

20. Visual Efficiency
Effectiveness of the Visual System to clearly, efficiently, and comfortably allow someone to gather visual information
Accommodation (i.e., focusing)
Binocular Vision (i.e., eye muscles and teaming)
Eye Movements (i.e., tracking)

21. Accommodation Disorders
Insufficiencies – Lens hardens, neuromuscular pathway problems
Excess – Muscles can not relax
Symptoms:
Blurred Vision
Headaches
Eyestrain
Avoidance of reading or other close work

22. Binocular Vision
The brainstem helps control eye movement. It directs the six muscles that keep the eyes moving together as you look up, down, right, and left.

23. Binocular Vision Disorders
Muscle weakness or Paralysis
Convergence Insufficiency

24. Binocular Vision Disorders
Strabismus- When two eyes lose alignment

25. Binocular Vision Disorders
Diplopia (i.e., Double Vision)
Common if the stroke or brain injury affects the cerebellum or brainstem

26. Eye Movements Fixation Saccades- (i.e., scanning)
Pursuits (i.e., tracking)

27. Eye Movement Disorders
Nystagmus
Visual Scanning Problems- decreased accuracy and speed
Visual Tracking Problems- unable to accuracy follow objects
Can affect a person from returning to activities of daily living including self care, reading, and driving

28. Visual Information Processing
This is where the true "seeing" takes place.
Taking in and organizing visual information from the environment
Integrating this visual information
Making a motor response

29. Visual Information Processing
Visual spatial skills
Used to interact the environment
Develop directional awareness
Develop good motor coordination and balance

30. Visual Spatial Dysfunction
Lack of coordination and balance
Clumsy, falls
Tendency to work with one side of the body
Reversing letters and numbers

31. Visual Information Processing
Visual Perception
The ability to interpret the surrounding environment by processing information that is contained in visible light.

32. Visual Perception Visual Discrimination- size, shape, orientation
Figure Ground- attending to a form while maintaining awareness of background
Visual Closure- determine final picture without all the pieces
Visual Memory- recognize and recall visually presented information

33. Visual Perceptual Hierarchy

34. Visual Processing Deficits
Common Visual Processing Deficits include:
Visual inattention
Visual neglect
Decreased speed of visual and cognitive processing

35. Visual Inattention
The inability to perceive a stimulus in a visual field when a similar stimulus is presented and perceived simultaneously in the same visual field
Most evident when searching for visual detail when array is complex and random

36. Visual Neglect Most severe form of visual inattention
Hemispatial neglect is a deficit in attention to and awareness of one side of space is observed. It is the inability of a person to process and perceive stimuli on one side of the body or environment
A person with left neglect may
hold their head or eyes to the right
may not look at you if you stand to their left
may not be able to locate items on the left
may run into objects on their left side

37. Visual Neglect Presentation of a person with left neglect may include:
hold their head or eyes to the right
may not look at you if you stand to their left
may not be able to locate items on the left
may run into objects on their left side

38. Visual Neglect

39. Speed of Visual Processing
People who sustain a neurological event often have decreased speed of visual processing
Functional scanning and processing speed is necessary for returning to competitive employment, school activities, and driving

40. Visual Motor Coordination
Ability to integrate visual information processing skills with:
Fine motor coordination
Visual motor integration

41. Visual Motor Dysfunction
Common symptoms with visual motor dysfunction:
Fumbling objects
Overshooting and undershooting
Difficulty writing
Slowed reaction times

42. What Can We Do? Assessment for and identify potential visual deficits
Direct your patient to the appropriate professional
Create functional goals for Visual Deficits
Provide treatment activities to retrain visual skills and/or teach ways to help compensate for vision deficits

43. Assessing for Visual Deficits
Clinical Observation
Look at functional vision during ADL completion
Bump into objects during ambulation
Overshoot/Undershoot when reaching for items
Miss items unilaterally
Squinting when looking at targets

44. Assessing for Visual Deficits
Interview
Does the patient report any visual changes?
Blurry or fuzzy vision
Visual Fatigue
Visual Fluctuations
Missing items

45. Assessing for Visual Deficits
Screening
Complete simple oculomotor screening
Fixation
Saccades
Pursuits
Convergence

46. Assessing for Visual Deficits
Screening
Complete screening for visual tracking, attention, and neglect
Letter Cancellation
Shape Cancellation
Line Bisection
Draw Clock

47. Letter Cancellation Task
Look at:
Accuracy (Percentage correct)
Scanning pattern (organized/disorganized)
Pattern for missed targets (all on one side or scattered)

48. Assessing for Visual Deficits
Complete standardized assessments
Visual Perception
Motor Free Visual Perceptual Test (MVPT)
Speed of Visual Processing
Trail Making Part A and Part B
Visual Motor Coordination
Dynavision D2

49. Dynavision D2
The Dynavision D2 Visuomotor Training System has proven effective for use in visual, cognitive, and physical rehabilitation.
The programmable options standard with Dynavision D2 software will enable the clinician to facilitate individualized treatment for clients of different ages, abilities, and conditions.
Performance data is quantitative and objective ensuring accuracy for initial evaluation and progress monitoring.

50. Dynavision D2

51. Treatment for Visual Deficits
Small Scale:
Cancellation tasks (letter, number, object)
Following picture models (block design, dot design)
Information seeking (store
advertisement, using printed
material, Computer)

52. Treatment for Visual Deficits
Medium Scale:
Matching and sorting activities
Locate target objects (Cards on table, target positions/pieces on game board)

53. Treatment for Visual Deficits
Large Scale:
Dynavision D2 activities
Visual Scanning during ambulation (i.e., Scavenger hunt)
Kinect
Wii
Active Passenger Tasks

54. Case Study “Mary”
Complaint of blurred vision and difficulty with computer usage at work.
Went to the eye doctor who sent her for additional testing due to concerns of Stroke in December

55. Initial Visual Field Test
Left Eye Right Eye

56. Evaluation
Patient is unable to complete daily activities due to visual deficits (i.e., working, driving, cooking)
Evaluation results include
Impaired visual scanning, processing, perception
Unable to read standard print or complete computer work
Dynavison D2 60-second trial Score: 50 Average Reaction Time 1.20 seconds
Intact UE and LE skills

57. Treatment Treatment included:
Recommend Skilled OT 3x/week which tapered to 2x/week as patient progressed
Completed 44 treatment session prior to discharge
Treatment included:
Training for functional visual scanning patterns
Activities to improve perceptual skills
Information seeking using printed material and computer tasks
Dynavision D2 to improve visual motor coordination and speed of visual processing

58. Repeat Visual Field Test
Left Eye Right Eye

59. Discharge
Mary did have some continued visual deficits, however was able to compensate well enough to return to independent living and driving.
Discharge Dynavision D2 60 second trial Score: 78 Average Reaction Time: 0.77 seconds

60. Questions?

61. References
Ciuffreda KJ, Suchoff IB, Marrone MA, Ahmann E., Oculomotor rehabilitation in traumatic brain-injured patients. J Behavioral Optom 1996; 7:31-38
Scheiman M, Gallaway MF., Vision Therapy to Treat Binocular Vision Disorders After Acquired Brain Injury: Factors Affecting Prognosis. In: Suchoff I, Ciuffreda, KJ, Kapoor N, ed. Visual and Vestibular Consequences of Acquired Brain Injury. Santa Ana: Optometric Extension Program; 2001
Suter, P., Harvey L., Vision Rehabilitation: Multidisciplinary Care of the Patient Following Brain Injury, CRC Press, New York, 2011
Schlageter K, Shaw R., Vision Therapy. OT Week, July 11, 1991.
Warren, M.L. (1993). “A Hierarchical Model for Evaluation and Treatment of Visual Perception Dysfunction in Adult Acquired Brain Injury” Parts 1 and 2, American J of Occupational Therapy, 47:42-66