VFD Lecture Part 4

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VFD Lecture Part 4
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Influence of VFD on Reading

• Pertinent Observations
• Makes errors reading text on reading acuity cards
• Mnread acuity
• Warren text card from biVABA
• Omits larger optotypes on blind side on
  intermediate acuity test
• Reads more accurately as optotypes decrease in
  size
• Makes errors on Pepper Visual Skills for Reading
  Test
• Makes errors on Telephone Number Copy Test from
  biVABA

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Visual Acuity Charts
Patient may omit letters on the VFD side when
reading the top rows. Example patient with LVFD
may miss the Z in the top row, the N,R in the
next row.
Patient may transform or omit words in sentence.
Example Patient with LVFD may read the top line
as His car is hot and the second line as The
hat is Black.
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Visual Skills for Reading Test(aka the Pepper
test)
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VSRT

• Assesses visual decoding components of reading
• Determines whether the scotoma border is close
  enough to the fovea to reduce the perceptual span
  and interfere with reading
• Does not measure comprehension

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VSRT Test Design

• Series of unrelated letters and words
• Increase in length from 1-2 to 7-10 letter words
• Line spacing decreases from triple space to
  double space to single space
• Spacing between words decreases
• Double spaced 1-11, single spaced 12-13
• Reading level 6-8th grade

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VSRT Test Design

• Visual components assessed
• Visual word recognition
• Non contextual, no semantic clues
• Forced to rely on vision for encoding
• Eye movement control
• Sequential reading saccades
• Long return sweep saccade to next line
• Placement of scotoma border
• Losing beginning or endings of words causing a
  transformation of the word and misidentification
• Omissions of words or letters on right or left
  side

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VSRT Test Design

• Provides profile of
• Reading accuracy
• Corrected reading rate
• Most persons read continuous text 1.6x faster
  than Pepper score
• Prevalent types of errors

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VSRT Test Procedure

• Select card with print size 1-2 sizes larger than
  pt can read
• Instruct patient to read letter/words on card out
  loud
• Record errors on scoring sheet
• Time patient performance

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VSRT Error Examples

• Misidentification
• Repetition
• Spells word
• Omission
• Insertion
• Connects words
• Separates words
• Changes word order
• Skip lines

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VSRT Test Procedure cont

• Test termination
• 10 consecutive errors
• Skipped line twice
• Fatigue of reader
• Exceeding 5 minutes
• All at the discretion of the examiner

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Example of Reading Errors on Pepper Test
1 2 3
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5
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Row 5 patient with LVFD might read fear as
ear Row 6 patient with RVFD might read funny
as fun
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Examples of Patient Performance Documented on
Scoring Sheet
Pt with LVFD, makes omissions due to abbreviated
scanning towards left and misreads left letters
of words causing misidentification
Pt with RVFD, misses or misreads right letters
of words causing misidentification and also
splits longer words and connects shorter words
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Telephone Number Copy

• Patient copies down a series of 10 telephone
• numbers

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Telephone Number Copy

• Test Materials
• Visual Attention Assessment form
• Telephone Number Copy subtest
• Black felt tip pen
• Stopwatch
• Test Environment
• Well lighted room with full and even illumination
  of the test materials

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Test Instructions

• Eyeglasses on if worn
• Place the subtest at the patients midline
• Instruct the patient to copy the telephone
  numbers and place the pen on the table when
  finished
• The patient may reposition the subtest form.
  Record any changes the patient makes to the
  placement of the form
• Begin timing when the patient begins reading the
  numbers

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Test Instructions

• Stop timing when the patient places the pen on
  the table
• note timing includes self corrections made when
  checking work
• Physical and verbal cuing is permitted
• Record cuing on test form
• Count the number of errors(omissions and
  misidentifications) made by the patient in
  copying the numbers
• An omission is leaving out a number in the
  sequence
• Misidentification is writing down an incorrect
  number
• If a patient copies down a number incorrectly but
  immediately corrects the error without cuing,
  note h/her performance on the test form but do
  not count it as an error

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Test Instructions

• Inform the patient of the number of errors and
  instruct h/her to find the errors and correct
  them
• This is not timed
• Record the number of omissions and
  misidentifications made both before and after
  self correction
• Record the percentage of correct telephone number
  sequences before and after self-correction
• Each number is considered a single item in
  calculating the percentage

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Telephone Number Copy
Example Patient with left visual field
deficit. line one leaves out number after the
dash (corrects)
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Evaluation of Low Functioning Patient

• Will be observational/subjective
• Must know status of visual acuity and oculomotor
  function first
• CT/MRI information about lesion site can suggest
  deficit
• Look for asymmetry in patients gaze
• Will make fewer eye movements toward VFD side
• Compare notes with other team members

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Evaluation of Low Functioning Patient continued

• If patient will track a target
• Position patient in secure postural position
• Bring brightly colored object across the field
  from the side
• An object that has both auditory and visual
  features makes the best target
• Observe tracking
• Dynavision Mode A on the Continuous 4 minute run
  also works well
• Patient may demonstrate asymmetrical gaze or
  slower gaze to light on deficit side