VISION AND ABI: A REHABILITATION APPROACH

Tanya Polonenko, OD, FAAO, FCOVDNovember 2, 2017

Henry David Thoreau

It’s not what you look at that matters, It’s what you see

Henry David Thoreau

Brainy Quote

Lecture Outline

Vision and ABI What is Vision? How is vision affected?

Vision Deficits after ABI Visual functional and visual information processing skills Implications of vision deficits

Visual-Spatial Deficits: Hemianopia Visual Inattention (neglect) Perceived Visual Midline Shift

Vision Rehabilitation What is it? Neuroplasticity Goals of Vision Therapy Improvements to expect Procedures Does it work?

How does ABI affect VISION?

Occipital Lobe (primary visual cortex)

Parietal Lobe (spatial inattention, perception)

Temporal Lobe (spatial organization, object recognition)

Frontal Lobe (initiates voluntary saccades and pursuits)

Midbrain and Pons (cranial nerves)

70% of our brain as Something to do with VISION

John Streff, O.D.

When vision is working well, it guides and leads in all that we do; when not, it interferes.

A: Vision is the ability to make a meaningful interpretation of what is seen.

Q: What is vision?

We need to gather and interpret visual information

Vision requires more than having 20/20 eyesight

These skills determine the speed, accuracy, endurance and comfort of gathering visual information

Visual functional skills:“how info gets into the brain”

Eye Focusing (Accommodation)

Eye Teaming (Binocularity)

Eye Tracking (Ocular Motility)

Visual-Vestibular Interaction Visual Field

Aiming/Aligning(Fixation)

Visual perceptual skills:“what the brain does with visual info”

Visual Discrimination Visual Memory Spatial

Relations

Form Constancy Figure Ground Visual Closure

Visual-Motor Integration

Directionality/Laterality

What is it? Focusing, following

Targets

Where is it? Aiming, scanning space

Background

When is it? Time judgement

context

The mind-eye connection

Who am I? How do I feel about it? Attention to detail Intentional movement

Awareness of context Habitual/anticipatory

movement

Where am I? Electrical signals

How Am I? Chemical signals

What do I do about it?

MIND

BODY

26-50% of those with ABI reported trouble with their vision most of the time…

The OBIA Impact Report 2012 https://www.ontario.ca/img/ontario@2x-print.png

Politzer, T. (2015, April 22) Introduction to Vision and Brain Injury. Retrieved from Neuro-Optometric Rehabilitation Association website https://nora.cc/for-patients-mainmenu-34/vision-a-brain-injury-mainmenu-64.html

Reduced ability to use VISION

The quality and amount of visual input into the brain

The brain’s ability to process normal visual input

Deficits with BOTH

Vision Impairment and ABI

Blur (sometimes intermittent) Double vision Difficulty tracking Trouble focusing Glare sensitivity and

photophobia Eye strain/fatigue Headaches Slow visuomotor performance Difficulties with balance and

posture

Accommodative dysfunction Vergence issues/misalignment Oculomotor abnormalities Visual Field Defects Perception Deficits Visual Inattention (Neglect) Perceived Visual Midline shift Visual-Vestibular Dry Eye

Symptoms Deficits

Kapoor N, Ciuffreda KJ. Vision Disturbances Following Traumatic Brain Injury. Current Treatment Options in Neurology. 2002:4: 271-280

Ciuffreda KJ et al. Occurrence of oculomotor dysfunction in acquired brain injury: A retrospective analysis. Optometry. 2007:78(4): 155-161.

Post Trauma Vision Syndrome(PTVS)

Symptoms Deficit

Blur Accommodation

Varying Blur with blink Tear Film Integrity

Inaccurate reading Ocular Motility

Eyestrain/double vision Vergence

Difficulty with visually stimulating environments

Visual-vestibular interaction

Light Sensitivity Light-Dark Adaptation

Missing a portion of vision Visual Field Integrity

Slow reading speed Visual Perceptual Processing

Behavioural Implications to VISION

Decreased confidence Increased anxiety and uncertainty in responding to the

environment Increased passiveness in decision making Difficulty with tasks in dynamic environments Increased fear of falling Community activities become challenging:

Driving Shopping Working Sports, leisure interests

Types of Accommodative Dysfunctions: Accommodative Insufficiency Accommodative Infacility Accommodative Excess

Symptoms Frontal Headache/Brow Ache Intermittent or Constant blur (distance, near, or both), worse when tired Pain around the eyes during visual activities Limited ability to read or use computer for long periods

Accommodation

Diplopia Constant or Intermittent Near or Far More evident in one position of gaze

Eyestrain/Fatigue after 10 minutes of performing a task driving, TV, reading, computers, studying…

Reduced depth perception

Clumsy

Vergence

Patients will close or cover an eye Squinting Falling asleep while reading Avoidance of prolonged visually demanding tasks Dizziness/nausea

Vergence

There are many areas of brain needed for tracking: Pursuits/Saccades: Brainstem

(Pons, Midbrain)

Fixation: FEF, Parietal lobe & \Prefrontal cortex (for attention)

Different pathways

Both need to know where objects are in space

•Control of saccades and pursuits

Cerebral

•Horizontal and Vertical Gaze Centers

Brainstem

•Control of eye muscles

Cranial Nuclei

•Execute the eye movements

Extra-ocular Muscles

Oculomotor

Associated Symptoms

Reading difficulties: Slower reading speed Loss of place/skipping lines Missing words Poor comprehension Print seems to move/swim/jumble

Difficulty tracking objectsDizziness/nausea/motion sickness

Oculomotor and Vestibular Systems

Vision integrates with balance through the Vestibular Ocular Reflex (VOR)

VOR: Maintains stable, bifoveal retinal images during head and body movements

Involves CN III and VI communicating with CN VIII (auditory nerve)

Visual-Vestibular DysfunctionAssociated Symptoms

Oculomotor Slow reading Loss of place Skipping lines/words Print swims on page Difficulty tracking Dizzy/nausea Sensitivity to visual

motion

Vergence Diplopia Eyestrain/Fatigue

after <10min Closing an eye Dizzy/nausea Motion Sickness

Associated Symptoms

Emphasis on Increased disequilibrium and sensitivity to multiply-visually stimulating

environments (grocery stores, malls, libraries)

Dizziness/Nausea/Disequilibrium/Vertigo with visual tasks (reading, TV, ambulation, computer)

Oscillopsia

Visual Field Loss

May occur due to damage to the eye, optic nerve, or brain

VFD is when an area of the visual field is missing Various types:

Central Scotoma – Missing the central field of vision Quadrantonopsia – Loss of vision in a specific quadrant Homonymous Hemianopia – Loss of vision from one half of

each eye resulting in missing information from one half of the field of vision

Visual Field Loss

Prevalence: 32.5% to 65% in ABI patients

88.9% unilateral

61.5% associated with stroke, 14.6% cerebral hemorrhage, 11.3% closed head trauma

Symptoms: Difficulty reading, ambulating, driving

Bumping into walls, doors, people, tripping

Implications of Visual Field Loss

Difficulty walking – steps/curbs, poor balance, walking along the wall

Leaving food on plate Misreading words, reading slowly Difficulty finding grooming items Missing details Writing off the line Increased time/assistance for dressing Trouble navigating the environment Difficulty driving and shopping in a crowded place

Visual Inattention (Neglect)

12-49% of right-brain strokes demonstrate visual neglect Unaware of one side of space Patients with neglect: Lean away from area of loss Patients with visual field defects: Lean towards the area of loss

Neglect

http://www.floiminter.net/psychology/brain_and_behaviour/dorsal_ventral.png

Visual Midline Shift Syndrome (VMSS)

aka Abnormal Egocentric Localization (AEL) Deviated perception of visual midline

Poor eye/hand coordination Postural changes Diminished ability to navigate environment

Houston K E. Measuring visual midline shift syndrome & disorders of spatial localization: A literature review & report of a new clinical protocol. J Behav Optom. 2010:21(4): 87-93.

Visual Sequelae of Stroke

Alignment/movement impairment – 68% Visual field impairment – 49% Low Vision – 26.5% Perceptual impairment – 20.5%

Rowe et al. A prospective profile of visual field loss following stroke: prevalence, type, rehabilitation, outcome. Biomed Research International. 2013: http://dx.doi.org/10.1155/2013/719096

Type of field loss

Complete homonymous hemianopia 54% Partial homonymous hemianopia 19.5% Quadrantanopia 15%

Rowe et al. A prospective profile of visual field loss following stroke: prevalence, type, rehabilitation, outcome. Biomed Research International. 2013: http://dx.doi.org/10.1155/2013/719096

Recovery

Spontaneous resolution (>10˚ H, >15˚ V) in 50-60% within first 6 months Little spontaneous improvement beyond 6 months

Resolution beyond 6 months demonstrated in multiple studies of various rehabilitation techniques Quadrant deficits adapt and compensate more easily

than hemianopic defects

Symptoms associated with Visual Perceptual Deficits

Confuses similarly shaped objects Difficulty recognizing

objects in different orientations Close to or overlapping other objects

Visual memory problems Difficulty following verbal directions

Han MH. (2007) The Role of the Neuro-Rehabilitation Optometrist. In Elbaum J, Benson D (eds.): Acquired Brain Injury: An Integrative Neuro-Rehabilitation Approach. New York: Springer, pp. 146-175.

Visual Information Processing

Clinically, the prognosis is guarded for visual perceptual therapy in patients with severe ABI

Goal of therapy: create strategies that maximize

performance

Strategies: Auditory strategies

repetition

different viewing perspectives

Form Discrimination

Ability to distinguish different types of forms (shape, colour, orientation, edge, motion cues)

Difficulties: Parietal and Temporal lobe damage Patients often have an inability to attend to subtle variations in

form affects the patient’s ability to recognize common objects (ex. mistakes

button for nickel)

Differentiating similar words: was vs saw

Figure Ground Perception

Involves the ability to distinguish foreground (part of perception that needs attention) from background

Separation of the foreground is accomplished by visual differences in colour, luminance, depth, orientation, texture, motion…

Patients have difficulty finding things in a cluttered space, finding sleeve of white shirt

Photosensitivity

Elevated sensitivity to lights (ALL light, or specifically fluorescent lighting)

Cortical and subcortical substrates resulting in anomalous dark and light adaptation

Tints for both indoors and outdoors (with polarization)

Blue/Gray tints: Fluorescent lighting

Treatment Options

http://www.algaecal.com/wp-content/uploads/options-treatment-guidelines-of-osteoporosis.jpg

Treatment: Vision

Proper Spectacle Prescription!

Filters

Yoked prism

OcclusionVision Therapy

What is Vision Rehabilitation?

An individualized treatment regimen prescribed to a patient in order to:

Provide medically necessary treatment to normalize diagnosed visual dysfunctions Vergence Accommodation Oculomotor

Improve visual comfort, ease and efficiency

Enhance visual performance to meet defined needs of the patient

Improve visual information processing Spatial organization Object perception Visual memory Visual attention Integration with other sensory modalities (motor, vestibular, auditory, etc)

Neuroplasticity and Therapy

Brain (visual system) is able to create new connections and fortify old onesby experience

Learning and plasticity can occur by myelination formation or re-modeling white matter

Neurogenesis continues throughout lifetimes

Examples: rapid functional plasticity in primary somatomotor cortex and perceptual

changes after nerve block through MRI

Visual development in adult amblyopes

1-4

Goals of Vision Therapy

Alleviate signs and symptoms

Achieve desired visual outcomes Clear, comfortable, single binocular vision Efficient coordination of visual functional skills Efficient visual information processing

Meet the patient’s needs

Improve the patient’s quality of life

Return to daily activities

5-26

Improvements to Expect

Oculomotor Skills Improved accuracy and speed of pursuit and saccades Reduced number of re-fixations and regressions while reading Increased span of recognition

Vergence Increased vergence ranges, speed, facility Reduced eyestrain, headache with near tasks

Accommodation Increased amplitude, flexibility, facility Improved quality and stability of near vision

Comfort Efficiency Accuracy Performance

5-26

Managing Expectations

Rehabilitation is a process that takes time

Initially program can cause symptoms to be exacerbated

Manage the increased symptoms while strength training Modify amount of time spent on exercises Slowly increase amount of exercises performed Monitor log for delayed symptoms Symptoms should not exceed 7 or 8/10

General Principles and Guidelines

Determine a level at which the patient can perform easily

Emphasize that changes must be made within their own visual system (we can’t do the work for them!)

Set goals (for both patient and doctor)

Use techniques that provide them with feedback (diplopia, blur, parallax, float….)

General Therapy Sequence

• Anti-suppression

• Awareness

Phase 1

• Monocular

Phase 2• Bi-ocular

Phase 3

• Binocular• Accomm• Vergence

Phase 4• Integration• Flexibility• Stamina

Phase 5

Eye FocusingEye Teaming (and depth)

Perceptual SpeedScanning (Eye Tracking)Visual-Spatial and Body Awareness with Visual Motor

Yoked Prism for Balance

Visual Perceptual

“Life Therapy”

Vision Rehabilitation for Acquired Brain Injury

Eye Focusing Training

Eye Teaming Training

Diplopia, Depth, and Field Loss

If the hemianopia causes an eye turn, it might help with field expansion or become more confusing Optometrist can determine how to treat the diplopia with

prism, fogged foil, and vision rehabilitation

Exercises: Work on vergence (brock string) emphasize spatial judgments and fine visual-motor

judgments with stationary and moving targets

Space matching

Judge the distance to an object and the height and width of the target

If able to walk, do so heel to toe (guess how many steps it will take to reach the object)

At same time, grasp string, indicating with the length of the string how wide you think the object is

Choose objects 2-15 ft away, vary location Can also toss bean bag and judge its distance Teaches how to judge distances with monocular cues and provides

feedback regarding these cues and size constancy

Perceptual speed critical for safety because people must scan, get the info from the blind field and return to a near straight-ahead position

Tachistoscopic Exercises:computer programsvision therapy instruments

Perceptual Speed

Without rehabilitation, the majority of hemianopes tend to adapt disorganized can paths with multiple re-fixations in the blind field and their intact field

fMRI studies showed reduced activation in the frontal, parietal, and supplementary eye fields during saccades

Scanning

Nelles, G et al. (2007). Saccade induced cortical activation in patients with post-stroke visual field defects. Journal of Neurology, 254 (9), 1244-1252

Scanning

3 step process improves hemianopic search field, decrease search times, improved daily living:

Practise large saccades (30-40˚) into blind field without head movement

Adopt a horizontal or vertical scanning strategy on tasks involving scanning an array for an object

Generalized to daily living eg scanning kitchen shelves for particular spices

Kerkhoff, G., et al (1994). Neurovisual rehabilitation in cerebral blindness.Archives of Neurology, 51 (5), 474-481.

Scanning

At home: “Post-It Note Scanning”

Place cards from a deck randomly across a broad expanse of wall. Sit several feet away from the wall in order to scan entire wall without moving head. Flip cards over from a second deck, scanning as quickly as you can for each card. The time to find all the cards is a measure of scanning efficiency

Hart Chart Saccades

VMI Continuous Motion

Space Fixator

Groffman Mazes

Michigan Letter Tracking

Scanning

MICHIGAN LETTER TRACKING

Scanning

SACCADIC WORKBOOK

PHONETIC FOCUS

Scanning

HART CHART

SACCADIC WORKBOOK

Scanning

Scanning

Incorporate Mobility: Scan into blind field with the eyes at a certain rhythm

(eg. Every 5th or 6th step) Walk down a hallway with photos placed on the walls.

Every other beat to the metronome, look to the affected side and state the picture on the wall

KEY: no head movement Helps efficient scanningMoving the head activates vestibular system

creates dizziness and disorientation

Neglect: scanning

Tracking printed words from a book on CD

Calling out first and last letter of: each word on a page of print each line Progress from large to small print

Colouring in specified letters of a word using a pencil Eg. Colour in all the “o’s”

Finding/counting specified words in paragraphs

Usually hemianopes have a misconception of visual space.

Direct or indirect methods to direct attention to neglected visual space

Learning to turn the head into the neglected field imbeds the neglect as the eyes never cross into the neglected field.

Key: incorporate proprioceptive, kinesthetic and auditory cues to ensure compete scanning of the environment

Visual-Spatial and Body Awareness: Visual-Motor Integration

Margolis Eye Throwing Technique

Close eyes and move eyes as far left as possible then open eyes and describe objects Tapping next to left eye and verbal coaching can help

“throw eyes to the left, scan to the right” Vibrating pager placed on left hip on a timer every 10-15 sec helps

remind to “throw eyes to the left”

Body Awareness

Angel’s in the Snow

Body Projection Person standing behind the patient touches different spots on his back Patient projects this by touching the corresponding points on the person in front

of them (or picture of person)

Shadow Walk In a dim room with a projector, have the patient stand so his shadow is on the

wall. Place a mark on his shadow in the middle of the neck. The patient is to walk toward the wall while constantly maintaining position of the wall mark in the middle of his neck shadow

Mirror Walk Same as shadow walk but in normal light. Place black tape vertically down

middle of patient, and down middle of a floor length mirror at the end of a hallway. Patient is to walk toward the mirror, keeping the body tape in line with the vertical black strip on the mirror

Body Awareness

Balloon Bunt Patient must bunt a balloon with the limb that it is thrown at

Obstacle course Patient must walk through the centre of doorways, hallways, or

other obstacles without touching them

Dowel Rod Pick-up Pick up differently oriented rods in the middle of the rod. The

rods can be placed in different orientations and different locations and kinesthetic feedback is given based on the weight distribution of the rod

Visual-Spatial Organization

Room Orientation Stand at entrance of doorway and identify margins, such as perimeter walls and furniture obstacles in

the room Practice going to places in the room with eyes closed using memory and visualization to navigate Uses combination of memory, sight, visualization, spatial orientation and visual closure to help navigate

accurately

Visual Clutter Place more objects on the left side and leave the right side uncluttered (helps bias visual attention to

the left)

Hallway Picture Walk Have the patient note the location of pictures on the right side as they walk down the hallway. Have him

locate them again on the return walk when they are on the left side

Door Frame Letter Search Place a vertical row of letters on either side of a doorframe. Call out the letters top to bottom going

left to right as you walk towards the door

Visual-Spatial Organization

Floor Plan outline Draw floor plan of the room you are in. Draw landmarks such as

door or window. Ask patient to indicate the position of the other objects in the room relative to the landmarks.

Next level: patient locates objects in the floor plan outline of a familiar room even though he may not be in the room

Tennis Ball Suspend a tennis ball (with letters drawn on it) from the ceiling.

Have the patient bunt the ball as it swings towards them. Have the ball swing in different directions, and the patient must call out letters on the ball

Visual-Spatial Organization

Bilateral Circles

Mazes

Yoked Prism for Balance

Influence plasticity of multi-sensory integration processes as well as cognitive processes related to their mental representation of visual space (Rode 2001) Alterations in body posture Changing center of gravity Improve higher cognitive levels Assists in judging distance and stabilization

Form Discrimination: Treatment

Practice sorting functional objects (ex kitchen utensils) Encourage identification by feeling (tactile cues) Using an adaptive approach – place items necessary to

function in a certain orientation Hang garden tools up separately instead of piled

Label important items

Organize items by location

Figure-Ground Treatment

Scatter items in front of patient, name an object and have the patient point to it. Increase the clutter as they improve

Use occupation based activities that focus on figure ground deficits

As an adaptive approach: Put only a few things on a nightstand Organize drawers Mark steps/wheelchair brakes/edges

“Life Therapy”

Life Therapy for Hemianopia

Meal Times Have someone sit on your affected side and make eye

contact Place utensils on affected side Cook together: search for safety hazards set up (eg. Running water, burner

left on, knife placed precariously) Scanning kitchen shelf for spices

Life Therapy

Navigation Go on a walk: describe scenery on affected side Use map to navigate Navigate a website designate certain tabs he must peruse

Develop a safe obstacle course

Life Therapy

Recreational Virtual Reality Board Game Night Spot the difference Solitaire Card games Complete the picture Multimatrix

Mini Golf Pool Bocce ball

DOES IT WORK?

12 non-strabismic individuals with mTBI and diagnosed vergence and accommodative disorders participated

6 weeks (2 sessions/wk, 3 hours each); half did oculomotor training (OMT) and half did placebo (P) training

Results: Improved amplitude and peak velocity of

vergence (pfv and nvf) accommodation (monocular and binocular)

Improved stereoacuity Improved visual attention Reduced near symptoms (CISS score)

No change in patients that did placebo VT

Thiagarajan P, Ciuffreda KJ. Effect of oculomotor rehabilitation on vergence responsivity in mild traumatic brain injury. J Rehabil Res Dev. 2013: 50(9): 1223-40.

Thiagarajan P, Ciuffreda KJ. Effect of oculomotor rehabilitation on accommodative responsivity in mild traumatic brain injury. J Rehabil Res Dev. 2014; 51(2): 175-92.

VT improves Vergence and Accommodation in Adults with mTBI

VT improves eye movements, reading rate, visual attention

12 subjects with mTBI participated in either oculomotor training (OMT) or sham training (ST).

6 weeks, 2 sessions a week. Trained vergence, accommodation, version in randomized order across sessions.

Visual attention assessed by VSAT

Results: Over 80% of abnormal parameters significantly improved Reading rate improved Amplitudes of vergence, accommodation improved Saccadic eye movements improved in rhythmicity and accuracy Improved visual attention and CISS score

Thiagarajan P, el al. Oculomotor neurorehabilitation for reading in mild traumatic brain injury (TBI): An integrative approach. NeuroRehabilitation. 2014. 34: 129-146.

VT improves eye movements and reading ability

5 adults with stroke and 9 adults with TBI 8 weeks of training, 2 sessions/week

Training included single- and multiple-line simulated reading, as well as basic versional tracking (fixation, saccade, and pursuit) using infra-red eye movement recording technology

Internal oculomotor visual feedback in isolation (4 weeks) or concurrent with external oculomotor auditory feedback (4 weeks)

Results: Improved objective accuracy with versional tracking Improved reading ability

Ciuffreda KJ, et al. Oculomotor rehabilitation for reading in acquired brain injury. NeuroRehabilitation. 2006. 21: 9-21.

VT improves clinical and fMRI measures in Adults with CI

13 control normal BV adults; 4 convergence insufficiency adults

All participated in 18 hours of VT

Results: Reduction in NPC and NPC recovery point Reduction in Near Phoria Improved PFV, average peak velocity of convergence Significant increased functional activity within the frontal

areas, cerebellum, and brain stem significantly

Alvarez TL, et al. Vision Therapy in Adults with Convergence Insufficiency: Clinical and fMRI Measures. Optom Vis Sci. 2010; 87(12): E985–1002.

fMRI shows brain changes with vergence training

Functional activity and vergence eye movements were quantified from 7 BV normal and 4 CI patients before and after 18 h of vergence training.

Results: CI patient measurements after vergence training were more similar to levels observed with BV normal Increased fMRI activity levels Increased speed in convergence response Improvement in CISS score

Alvarez TL et al. Functional activity within the frontal eye fields, posterior parietal cortex, and cerebellar vermis significantly correlates to symmetrical vergence peak velocity: an ROI-based, fMRI study of vergence training. Front. Integr. Neurosci., 2014; http://dx.doi.org/10.3389/fnint.2014.00050

Vergence peak velocity and phoria improves with VT

12 BV normal patients and 4 CI patients. CI patients underwent 18 hours of VT.

Results: After VT, peak velocity and exophoria magnitude improved significantly in CI patients

Alvarez TL. A pilot study of disparity vergence and near dissociated phoria in convergence insufficiency patients before vs. after vergence therapy. Front. Hum. Neurosci.2015; http://dx.doi.org/10.3389/fnhum.2015.00419

Family Physician Occupational Therapist Physical Therapist Speech and Language Therapist Case manager Psychologist Classroom Teacher and Tutors Workplace

Professional team collaboration

Referral Process

Referral to the Binocular Vision Clinic (519-888-4567 ex 32395)

Need medical info from last eye exam and if able physician

Student perform assessment under the supervision of an attending Optometrist

Dr. Tanya Polonenko is the attending OD on Mondays

Can book directly

Medical history is helpful

HighMark Health: 905-232-7002 Highmarkhealth.ca

VFVC: 905-303-9775 Vaughanvision.com

University of Waterloo HighMark Health or VFVC

Summary

ABI can impact many aspects of vision Depth, visual functional skills, visual information processing, visual

field, visual attention

The brain is neuroplastic and can form new connections

Numerous studies have demonstrated improvement in scanning ability and daily life activities with vision rehabilitation

In-office vision therapy is the most effective, but at-home vision therapy is an option

ABI is multi-faceted and benefits from a multi-disciplinary approach from a health team

References Bolognini, N et al (2005). Visual search improvement in hemianopic patients after audio-visual stimulation. Brain. 128:2830-2842

Bowers AR el al (2012). Clinical study: A pilot evaluation of on-road detection performance by drivers with hemianopia using oblique peripheral prisms. Stroke Research and Treatment Volume 2012, Article ID 176806, 10 pages. doi:10.1155/2012/176806

Ciuffreda KJ (2002). The scientific basis for and efficacy of optometric vision therapy in nonstrabismic accommodative and vergence disorders. Optometry. 73: 735-62.

Ciuffreda KJ et al. (2007) Occurrence of oculomotor dysfunction in acquired brain injury: A retrospective analysis. Optometry. 78(4): 155-161.

Houston K E. (2010) Measuring visual midline shift syndrome & disorders of spatial localization: A literature review & report of a new clinical protocol. J Behav Optom. 21(4): 87-93.

Kapoor N, Ciuffreda KJ. (2002) Vision Disturbances Following Traumatic Brain Injury. Current Treatment Options in Neurology. 4, 271-280

Kasten, E. et al. (2001). Stability of visual field enlargements following computer-based restitution training – results of a follow-up. Journal of Clinical and Experimental Neuropsychology, 23(3), 297-305.

Kerkhoff, G., et al (1994). Neurovisual rehabilitation in cerebral blindness. Archives of Neurology, 51 (5), 474-481.

Margolis, N et al. (2006). Visual field defects and unilateral spatial inattention: diagnosis and treatment. J Behav Optom. 17(2):31-37.

Nelles, G et al. (2007). Saccade induced cortical activation in patients with post-stroke visual field defects. Journal of Neurology, 254 (9), 1244-1252

Pambakian, ALM and Kennard C. (1997). Can visual function be restored in patients with homonymous hemianopia? British Journal of Ophthalmology. 81:324-323.

Perez C and Chokron S. (2014). Rehabilitation of homonymous hemianopia: insight into blindsight. Frontiers in Integrative Neuroscience. Volume 8 Article 82.

Pizzamiglio, L et al. (2006). Development of a rehabilitation program for unilateral neglect. Restorative Neurology and Neuroscience 24: 337–345

Politzer, T. (2015, April 22) Introduction to Vision and Brain Injury. Retrieved from Neuro-Optometric Rehabilitation Association website https://nora.cc/for-patients-mainmenu-34/vision-a-brain-injury-mainmenu-64.html

Romano, JG. (2011). Rehabilitation of hemianopic visual field defects. ACNR. 11 (1): 31-33.

Rowe et al. (2013) A prospective profile of visual field loss following stroke: prevalence, type, rehabilitation, outcome. Biomed Research International. http://dx.doi.org/10.1155/2013/719096

Sutter P and Harvey LH (editors). Vision Rehabilitation: Multidisciplinary Care of the Patient Following Brain Injury. 2011. Taylor and Francis Group, Florida

THANK YOU!dr.tpolonenko@gmail.com