Vision Flashcards

1
Q

Typical population in children with vision deficits

A
  • Cerebral Palsy
  • Down Syndrome
  • Spina Bifida
  • Low Birth Weight Syndrome
  • Pervasive Developmental Delay (PDD)
  • Sensory Integrative (SI) dysfunction
  • Child Abuse
  • Neglect
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2
Q

Typical population in adults with vision deficits

A
  • Acute vision problems occurring after CVA
  • head trauma
  • spinal cord injuries (SCI)
  • progressive impairments in MS
  • Parkinson’s disease
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3
Q

Eye care specialists

A

Ophthalmologist - medical doctor who specializes in diseases of the eye and perform eye surgery

Optometrist - primary health care provider who specializes in examination, diagnosis, treatment, and management of disorders of the visual system, eye, and associated structures; as well as diagnosing eye conditions

Neuro-optometrist - subspecialty of optometry; perform diagnostic testing to determine specific acquired visual dysfunctions of deficits that are related to physical injury, TBI, or other neurological (CP, MS). Can prescribe lenses and prisms as well as vision therapy

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4
Q

Vision Rehab Professionals (certifications)

A

Certified Low Vision Therapist (CLVT) - Bachelors degree or post-graduate certificate (OTs can do this but SCLV is preferred), scanning and tracking using LV devices

  • Certified Vision Rehabilitation Therapist (CVRT) - reading and writing Braille and other tactile languages
  • Certified Orientation & Mobility Specialist (COMS) - cane travel, navigate indoor and outdoor environments, general safe travel skills
  • Specialty Certified Low Vision (SCLV) - AOTA offers a specialty certification in low vision to OTs and OTAs

OT - evaluates occupational performance relative to visual deficit, restores and/or adapts visual skills to improve performance

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5
Q

Visual Integrity:

Visual Acuity

A
  • A measure of the smallest high-contrast detail one can see
  • -Typically measures with letters or words via charts
  • -20/20 is considered normal
  • -20/60 = a person can see detail from 20 feet away the same person with normal eyesight that can see from 60 feet away
  • -Measured NEAR and FAR distance
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6
Q

Visual Integrity:

Contrast Sensitivity

A
  • determines a person’s ability to see details even in the presence of diminishing contrast
  • related to visual acuity but a better predictor of reading performance, mobility, driving, face recognition and ADL abilities

-measured in 0-100% thresholds

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7
Q

Visual Integrity:

Refractive Disorders and the 4 types

A

-How light enters the eye

Types:
Emmetropia - normal vision; absence of refractive error, light rays focus on retina

Hyperopia (farsighted) - light rays focus behind the retina
–average person has this slightly and accommodation can help compensate

Myopia (nearsighted) - light rays focus in front of the retina

Astigmatism - vision is blurred at near and far due to an oval shape of the eye

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8
Q

Visual Efficiency Skills:

Binocular Vision Disorders

when should eye alignment occur in children?

what population does Binocular Vision Disorders typically occur in?

A

Strabismic - misalignment of eyes

  • Esotropia - turned in
  • Exotropia - turned out
  • Hypertropia - turned up
  • Hypotropia - turned down

Non-Strabismic - misdirection of gaze

  • Esophoria - eye aims at point nearer (undershooting)
  • Exophoria - eye aims at point further (overshooting)

developmentally –> eye alignment should occur during infant’s first month

more common in developmentally delayed children’ learning disabled children, and adults with ABI

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9
Q

What is Amblyopia?

How does it happen?

What is an intervention option?

A

AKA “lazy eye”

  • condition in which visual acuity is less than 20/20 and this acuity loss cannot be attributed to refractive error or observable eye disease
  • prescription glasses will NOT improve acuity in this case
  • Neurophysiological problem in which visual pathway from one eye to visual cortex does not develop normally or deteriorates

Treatment: Patching (the good eye) is the most common treatment to retrain the weak eye to work

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10
Q

Oculomotor Control

Saccades

how quickly does it occur?

A
  • allows you to “sample” the visual world by quickly noting new things
  • Occur quickly ~20ms
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11
Q

Oculomotor Control

Smooth Eye Pursuits

A

-Allows for slow systematic scanning around the visual world

  • slower movements
  • allows you to “lock-on” to a visual target and follow it
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12
Q

Ocular Motility Disorders (what are the problems?)

Populations that have this problem?

How can it be identified?

A

Eye movement problems in fixation, saccades, or pursuits

  • ocular motility skills take longer to develop in children ~early elementary school years
  • can be in cases of acute brain injury and in children with learning and reading disabilities
  • can be identified during an eye exam
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13
Q

Visual Information Processing:

Visual Spatial Skills

how is this important for children?

A
  • allows a person to make judgements about the location of objects in visual space in reference to other objects and self
  • awareness of left, right, up, down, front, and back
  • Note: preschoolers (3-4 years old) can typically identify front/back and up/down
  • *6-7 years old can do right and left on self
  • *7-12 years old can do right and left on objects in space

**Important for letter identification b/d/p

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14
Q

Visual Information Processing:

Visual Analysis Skills
(4 parts)

How does this apply to infants?

A
  • Being able to determine a whole without seeing all of the parts, ignore extraneous details, identify more important features, and use visual memory
  • face recognition, size, and shape consistency are present by 6 months of age
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15
Q

Visual Information Processing:

Visual Motor Integration Skills

How does it apply to children and drawing?

A

-individual’s ability to integrate visual processing information skills to fine motor movements (hand-eye coordination)

  • By 5 months = infant typically able to integrate the eye and hand.
  • ability to reproduce visual form develops in preschool years –>

1 1/2- 2 years old: first attempts at drawing

3: circle

4 1/2: square

5-5 1/2: triangle

8: diamond

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16
Q

Hierarchy of vision

A

Foundational skills - oculomotor control, visual fields, visual acuity

Visual attention - if and how a person attends to stimuli

scanning -desire and ability to locate objects

Pattern recognition -identify salient features of an object

Visual Memory -create and retain a visual image of something

Visuocognition - ability to manipulate and integrate visual input with other sensory systems to gain knowledge, solve problems, formulate plans, and make decisions

17
Q

Visual Fields

Commonly damaged from what condition?

What is the role of OT?

A
  • Damage is common following CVA

- Role of OT: differentiate between field loss vs neglect

18
Q

Visual Attention

Bottom-up factors vs top-down factors

A

Bottom-up factors: Characteristics of the scene/environment
-stimulus salience = stimuli that attract attention due to their properties (color, contrast, and orientation)

Top-down factors: characteristics of the person

  • Task of goals when looking at a scene:
  • -where to attend (spatial attention)
  • -What features to attend to? (feature-based attention
19
Q

Pattern Recognition

Figure Ground and Form Discrimination

A

Figure Ground - allows us to identify the foreground from the background (ability to find an item within a visual field )

Form Discrimination - Recognizing items regardless of how representative of the category they are

  • Face recognition = facial expressions and specific faces of people
  • Form recognition = allows to recognize items from different angles
20
Q

what is Visual Memory and why is it important?

what is visual spatial memory?

A

-short term and long term

  • allows to keep more information in mind than can put in words
  • allows to make quick decisions about information
  • allows to plan for future

visual spatial memory - being able to visually navigate even with closed eyes

21
Q

Visuocognition

A
  • selecting relevant information from the visual environment based on past experiences
  • -includes: memory, motivation, preferences
22
Q

Visual Disorders following TBI

A
  • Binocular disorders
  • Accommodation disorders
  • Eye movement deficits
  • Visual Field loss
  • Visual Perceptual deficits
  • Unilateral neglect
23
Q

Visual Disorders following TBI:

Binocular Visual Disorders

A
  • issues with processing information with BOTH eyes as needed
  • strabismus and non-strabismus binocular issues can result in diplopia, blurriness, or visual confusion
  • paresis of CN III, IV, and VI (strabismus)
  • convergence insufficiency and overall decreased visual fusion (non-strabismus)
24
Q

Visual Disorders following TBI:

Accommodation Disorders

what is accommodative insufficiency?

Common complaints?

A
  • Accommodative insufficiency - eye cannot change perception when distances change
  • complaints of visual fatigue with near visual work, difficulty shifting focus between near and far objects, and decreased visual clarity
25
Q

Visual Disorders following TBI:

Eye movement deficits

Which movements?

What VP skills can it impact?

A
  • pursuits and saccadic difficulties
  • difficulty tracking, locating, or visually following an object

VIP skills impacted:

  • visual closure - ability to find entirety of item when it is partially obscured
  • figure ground - ability to find an item within a visual field
  • visual memory - remember what item look like visually

*Nystagmus may be present = clients sometimes complain of nausea with blurry vision and nystagmus (repetitive uncontrolled movements)

26
Q

Visual Disorders following TBI:

Visual Field Loss

What are the damages to optic pathways?

A
  • lesion/damage to optic nerve = total loss of vision in one eye (blindness)
  • lesion/damage to optic chiasm = bitemporal hemianopsia (lose visual field on the temple side of each side)
  • lesion to optic tract = homologous hemianopia (most common; partial visual field loss )
27
Q

Visual Disorders following TBI:

Visual Perceptual Deficits

A

-can occur with injury to cortical or midbrain areas = involving parietal and/or occipital lobe lesions and injury

problems include:

  • agnosia (prosopagnosia, object agnosia, achromatopsia agnosia, simultanagnosia)
  • depth perception
  • figure ground
  • form perception/constancy
  • spatial relations
28
Q

What is Agnosia

A

Associative - can describe but not recognize objects
-can copy images but can’t tell you what they copied

EX: know that a fork is something to eat with but looking at it may call it a spoon

Apperceptive (worse)

  • unable to describe, recognize, or discriminate between objects
  • not able to copy images –> drawing is intelligible

Prosopagnosia - trouble interpreting facial expressions

-Visual equivalent of apraxia and aphasia

29
Q

Assessments for Visual Perceptual Impairments:

Brain Injury Visual Assessment Battery for Adults (BIVABA)

A

purpose - assess visual acuity, contrast sensitivity, visual fields, pupil response, visual search, visual attention, eye dominance

  • includes visual screening and higher order VP skills
  • for 14+ and neurological impairment post TBI
  • not good for children when visual is still developing
30
Q

Assessments for Visual Perceptual Impairments:

Motor Free Visual Perceptual Test (MVPT)

A

Purpose: provides measure of “motor free” visual perception in visual discrimination, form constancy, visual memory, visual closure, spatial orientation, figure ground

Population: 3+ through adulthood (more for adults)

Format: Flipping cards

  • for those with motor impairments such as stroke
  • Very global = cannot identify specific problem
31
Q

Assessments for Visual Perceptual Impairments:

Test of Visual Perceptual Skills (TVPS)

A

Purpose - “non-motor” assessment for VP skills

Assess - visual discrimination, visual memory, visual spatial, form constancy, visual sequential memory, figure ground, visual closure

Population: 4-18 (more for children)

  • appropriate for development issues
  • global level - cannot identify specific problem
32
Q

Assessments for Visual Perceptual Impairments:

Hooper Visual Organization Test (VOT)

A

Purpose: assess visual organization and closure

Population: adolescents aged 13+

Format: uses 30 line drawings of objects

33
Q

Assessments for Visual Perceptual Impairments:

Visual Motor Integration (VMI)

A

Purpose: Visual MOTOR skills

Population: 2+ in practice (more with children than adults)

  • Requires copying and fine motor skills
  • Global level
34
Q

Interventions for Vision:

Remedial Approaches:

A
  • Focus on identified deficit and attempts to diminish it through direct intervention
  • -patching, visual occlusion, computerized visual training
Techniques: 
-Visual fields: can be improved with intensive stimulation of the blind hemi-field 
--Dynavision, VRT
or use refractive lenses
--Fresnel prisms 
  • Visual Acuity: can be enhanced with increased illumination, increased contrast, and use of corrective lenses
  • Oculomotor control: improved with intensive exercises, such as using a brock string, patching
35
Q

Interventions for Vision:

Compensatory Approaches:

A
  • Concentrate on person’s residual abilities and attempts to use them to minimize the influence of areas of deficiencies
  • Scanning training, adaptive equipment, and aides, self-awareness training

Techniques:

  • Education of client to increase awareness of deficit
  • Awareness training includes teaching client to recognize and correct errors during performance

*Generally = same techniques as awareness training but specific to visual impairment issues

36
Q

Optometric Treatment Methods

A

Prisms (temporary or permanent) - neutralize acquired strabismus, improve spatial and midline awareness, and/or expand visual field
*OTs cannot trial prisms without an optometrist order, neuro-optometrist or optometrist prescribe and trial prisms with clients

Occlusion - total occlusion should only be used when diplopia is constant and lenses, prisms, or partial occlusion has been ineffective
-Black eye patches, clip on patch, taping, or foil can be used

Low vision aides

Vision therapy

37
Q

Partial vs Full Occlusion

A
  • need doctor’s order for either one
  • need to be mindful of when client should be wearing visual occlusion (during specific task or all the time)
  • need to be mindful of what circumstances the client should be wearing visual occlusion (when navigating spaces, when completing basic ADLs)
  • need to be mindful of safety concerns that you have for client when wearing visual occlusion (safety with walking in unfamiliar or busy spaces)
38
Q

OT training guidelines for vision

A
  1. Teach organized left-right scanning patterns in central visual space
  2. Teach organized left-right scanning patterns in peripheral visual space
  3. Reinforce visual experiences with sensorimotor experiences
  4. Emphasize conscious attention to detail and careful inspection and comparison of objects in impaired visual space in a slow, double-checking manner
  5. Practice skills in occupational activities
39
Q

OT treatment Considerations for vision

A
  • GRADE
  • make client aware of challenges before engagement in early stages
  • adapt the environment to improve client success
  • Goal: successful adaptation to the environment
  • remediation of lower level skills should improve visuocognition performance