Vision for the neuro client Flashcards
What is the difference between an optometrist and an ophthalmologist?
Opthalmologist
- MD
- Residency in opthalmology
- Diagnose and treat medical conditions causing visual impairments
- Board certified neuro-opthalmologists
Optometrist
- Independent healthcare provider
- Doctor of optometry from a postgraduate university program
- Specialize in neurorehabilitative optometry
- Not an M.D.•
- Diagnose and treat medical conditions causing vision loss.
What components of Mary Warren’s Hierarchy of Visual Perceptual Processing did we discuss in lab?
- Mary Warren
- biVABA
- Brain Injury Visual Assessment Battery for Adults
- 17 subtests – measure visual processing ability
- Hierarchy:
- Highest order: Visual Cognition
- Visual Memeory
- Pattern REcognition
- Scanning
- Visual Attention= alert and attending
- Oculomotor Control, Visual Fields, Visual Acuity
What are some things that you should look for when observing the general appearance of a client’s eyes?
- Pupil size
- Pupil symmetry
- Eyelid function
- Eye alignment
- Cervical position
- Body position
- Nystagamus
How is visual acuity assessed?
- Visual Acuity: always test with glasses on, both eyes. Mark at 10ft (or whatever chart says) write # of errors made on each line. Then do each eye.
- Snellen Fraction (20/20)
Optotypes
- Acuity = the smallest line of optotype that can be read with good accuracy.
- 20/20 = Standing as a distance of 20 feet, the viewer can see the letter that a person with normal vision can see at 20 feet.
- 20/200 = Standing at a distance of 20 feet, the viewer can see a letter that a person with normal vision can see at 200 feet.
- Near Vision -reading
- Intermediate Vision- not super far/ tv or clock/ separate chart
- Far Vision
- Contrast Sensitivity
List symptoms that a client may report with decreased visual acuity.
Identify interventions for visual acuity.
Decreased Central Acuity:
- Discrimination of small visual detail
- Distinguish contrast and color
- Reading, writing and fine motor coordination
- Examples: reading recipes, dialing a phone, applying make-up
Decreased Peripheral Acuity:
- Decreased mobility
- Decreased orientation in environment
- Identification of landmarks, obstacles in path, motion
- Examples: driving, shopping, community participation
Client reports:
- Inability to read print
- Print is too small
- Print is too faint
- Print is distorted
- Parts of words are missing
- Words run together
- Words swirl on page
- Decreased ability to see faces clearly
- Difficulty distinguishing colors of similar hues
Acuity Intervention
- Increase background contrast
- Increase illumination
- Reduce pattern background
- Enlarge objects or features that need to be seen
- Organize
What cranial nerves are involved in oculomotor function and what deficits occur when there is an impairment to each nerve?
Cranial Nerve III: Oculomotor Nerve
- Superior rectus
- Inferior rectus
- Medial rectus
- Inferior oblique
- Levator palpebrae
- Sphincter pupillae
- Ciliaris muscle
- Impaired vertical eye movements
- Lateral diplopia for near vision tasks
- Dilation of pupil and impaired accomodation
- Ptosis of eyelid
Cranial Nerve IV: Trochlear Nerve
- Superior Oblique Muscle
- Impaired downward and lateral eye movements
- Vertical diplopia for near vision tasks
- Downward head tilt with bilateral lesion
Cranial Nerve VI: Abducens Nerve
- Lateral Rectus Muscle
- Impaired lateral eye movements
- Lateral diplopia for far vision tasks
ALL:
- Disconjugate gaze
- Dysmetric eye movement
- Convergence insufficiency
How is oculomotor function assessed?
Client reports diplobia- common with oculomotor decrease function
Assessment:
- ROM
- Pursuits
- Saccades
- Convergence
- Visual Fixation
- Visual Pursuit Eye Movements or Tracking
- Right Eye and Left Eye
- Full ROM or Limited ROM
- Smooth or Jerky Pursuits
- Head Movement
- Body Movement
- Nystagamus
- *Note direction of gaze if not WNL’s.
- Saccades
- Completes 5 round trips
- Accurately fixates on the 2 targets (Undershoots or Overshoots Right or Left)
- Head Movements
- Body Movements
- Nystagamus
- * Note direction of gaze if not WNL’s.
- Convergence
- Near point of convergence
- Stereopsis- depth perception problems
Identify interventions for oculomotor function.
- Occlusion- eye patch with dr. orders
- Prisms
- Eye exercises
- Surgery
What are the normal ranges for the visual fields?
What is perceptual completion and how does it affect a visual field deficit?
External world that can be seen when a person looks straight ahead
- Superior – 60 degrees
- Inferior – 75 degrees
- Nasal side – 60 degrees
- Temporal side – 100 degrees
Perceptual Completion
Changes in:
- Visual processing
- Search patterns
- Scope of scanning (narrow)
- Speed of information processing
- Adaption to fast-paced and dynamic environments
List some functional deficits seen after a visual field cut.
- Awareness is slow and delayed secondary to perceptual completion (have to convince them bc brain thinks they can see everything)
- Decreased reading speed
- Decreased search in the environment
- Client runs into objects on side with the blind field
Macular portion of the visual field:
- Miss or misidentify visual details
- Reading – Normal perceptual span for saccadic eye movement is 18 characters
- Numbers
- Protective strategy
- Occupations that require monitoring of the entire visual field.
On same side as dominant hand:
- Decreased visual guidance of dominant hand in fine motor activities
- Decreased writing legibility
- Sense of Anxiety
- Decreased self-confidence
- Decreased participation in community
How are visual field deficits assessed?
Identify interventions for visual field deficits.
Assessment:
- Perimetry
- Confrontation testing: Use in conjunction with clinical observation. Cover the eye that will not be assessed. Eyeglasses Off
- Scanning Laser Opthalmoscope (SLO)
- Tests determine is a VFD is present, size, and location
- Dynavision
Interventions:
Successful compensation:
- Client must believe deficit exists
- Visual input from the blind side cannot be trusted
- Organized and thorough search of blind field
- Search:
- Peripersonal space- up close P and F search
- Extrapersonal space- in environment
Strategies toward the blind side: TEACH THESE
- Initiation of wide head turn
- Increase in head and eye movements
- Faster completion of head and eye movement
- Organized and efficient search pattern
- Attention to and detection of detail
- Shift attention between central and peripheral fields
If Limitations in reading:
- Saccades don’t match perceptual span
- Prereading exercises
- Word scans and word searches
- Red line – read all the way until you see the red line
- Bold-lined paper
- Monitor pen tip
- Tracing activities
What is normal visual attention and scanning, and what occurs when there is a deficit in visual attention and scanning?
Visual Attention and Scanning:
- Ability to observe objects closely and carefully to discern information and features
- Shift visual focus from object to object
Deficits:
Hemi-inattention/ neglect:
- Avoidance in searching the left half of visual space.
- Search begins and is confined to right half of visual space
- Right hemisphere injuries
- Left hemisphere – attention of right half of visual space
- Right hemisphere – attention to right and left half of visual space
Right hemisphere lesions:
- Fixate first on most peripheral visual stimuli
- Reluctance to rescan- will rescan if it’s a field cut
- Left hemisphere lesions:
- Symmetrical decrease in searching for detail
Both hemispheres:
- Slower scanning
- More erratic fixation patterns
- Decreased engagement in selective attention
- Decreased execution of organized and efficient visual search strategy
How are visual attention and scanning deficits assessed? I
- Near Space or Peripersonal Space
- Distant Space or Extrapersonal Space
Near or Peripersonal Space Search Patterns:
- Clockwise
- Counter-clockwise
- Rectilinear- left to right
- Counter-clockwise with a twist
Near or Peripersonal Space
- Single Letter Search
- Word Search
- Complex Character Search
- Scan Board
Distant or Extrapersonal Space (post it treasure hunt)
Scancourse:
- Number of accurate responses
- Misses numbers on one side of hall
- Randomly misses numbers on both sides of hall
- Unable to walk/wheel while reading numbers
- Misses cards placed in unexpected locations
- Verbal cues provided
Initiate an organized search strategy
- Carry out the search strategy in an organized and efficient manner
- Obtain complete visual information from visual search
- Correctly identify visual detail
- Search ability as visual complexity of task increases
What is the difference between a
visual field deficit and a
hemi-inattention?
- Left hemianopsia
- left-to right search pattern
- errors to left
- Left inattention
- asymmetrical search pattern
- search confined to right side
Identify interventions for visual attention and scanning deficits.
Intervention:
Reorganize scanning pattern
- Left to right linear scan to identify small visual details
- Left to right clockwise or counterclockwise scan of extrapersonal space
- Item-by item search of the visual array
Compensatory Strategies:
- Scan broad visual space
- Interact physically with target
- Conscious attention to visual detail
- Attention to left half of visual space by occluding right half of visual space
- Practice search strategy within context for carryover
Environmental Modification:
- Reduce background pattern
- Adequate room and task illumination
- Increase contrast between background and foreground objects
