What are the foundational skills in Warren’s Hierarchy for Visual Perceptual Development?
oculomotor control: ability to move the eyes in tandem to produce single visual image (binocularity)
visual field: what you see without moving your head
visual acuity: sharp vision; function of fovea in retina
Why is Warren’s Hierarchy useful?
It is a development framework for eval/tx of visual-perceptual deficits. Higher skills build on lower ones and are impacted by disruption of lower skills. Tx addresses lower skills to help restore higher ones.
Diplopia:
What are the six extra ocular muscles and their functions on the eyeball (from neutral)?
Visual acuity deficits:
►7 visual acuity interventions:
Visual field deficits:
loss of vision in part of normal field of view:
What is hemianopsia?
a deficit in which each eye loses half its visual field
Three types of hemianopsia:
Binasal: loss of nasal half of vision in both eyes
Bi temporal: loss of temporal half of vis. in both
Homonymous: loss of same half of each eye
VFD cause and impact:
Cause: often stroke/tbi
Impact: client gets dependent on perceptual fill-in (AKA perceptual completion) so is unaware of what’s really there; visual search function slow and delayed; can produce anxiety
►VFD intervention using mobility:
►scanning activities for mobility:
►VFD intervention: reading
Unilateral neglect (UN):
effects of neglect
UN severity level/ways of classifying:
►behavioral indicators of neglect
evaluating neglect:
Specialist needed for neuro-opthalmic evals, but these OT screens can determine referral needs:
►Cancellation tests (to evaluate neglect)
multiple variations, including:
other ways to evaluate visual-perceptual problems:
drawing and copying designs such as flower, house, tree, clock
►Interventions overview (for neglect):
saccades evaluation:
King-Devick test, in which pt. performs functional tasks dependent on visual-spatial organization
training saccadic movement
trunk rotation:
Rotating trunk, head and neck to affected side reduces symptoms of neglect.
*Think of activities that produce trunk rotation in high- and low-tone situations.