BVP - Introduction to Clinical Management of Binocular Vision Disorders - Week 5 Flashcards
What is the tradeoff of having a greater vs a smaller binocular field?
The greater the binocular field, the better the stereopsis, but the smaller the peripheral field
The smaller the binocular field, the poorer the stereopsis, but the greater the peripheral field
What 5 sensory input problems can compromise normal binocular vision?
Disease process affecting the retina centrally Strabismus Amblyopia Lack of sensory funsion (idiopathic) Monocular
What 2 motor output problems can compromise normal binocular vision?
EOM - anatomical/neurological
Poor sensory motor integration
What 3 accommodation vergence problems can compromise normal binocular vision?
Accommodation problem
Vergence problem
Accommodation vergence crosslink problem
When blur stimulates accommodation, what happens as a result and how is this process crosslinked to vergence? what does it eventually result in (2)?
Fast accommodation integration occurs, which is crosslinked with vergence, resulting in a vergence error.
This leads to slow vergence integration and eventually a vergence response.
When disparity stimulates vergence, what happens as a result and how is this process crosslinked to accommodation? what does it eventually result in (2)?
Fast vergence integration occurs, which is crosslinked with accommodation, resulting in a focus error.
This leads to slow accommodation integration and eventually an accommodation response.
What are 5 conditions that can result in unworkable or no binocular vision?
Suppression ARC Eccentric fixation Ambylopia Visual efficiency problem
Define the following:
Visual integrity
Visual efficiency
Visual information processing
Visual integrity - eye health and visual acuity
Visual efficiency - clear and comfortable vision
Visual information processing - understanding and analysing what we see
List some typical symptoms of BV issues (14).
Headaches associated with near work Blurred vision Diplopia Avoidance of near tasks Inability to sustain near vision Difficulty concentrating on near tasks Symptoms with prolonged near work Eyestrain or fatigue with near work Near/distance blur with changing fixation Words moving or running together Blinking, tearing, redness Squinting/rubbing with near work Poor attention with reading/homework Loss of place, slow reading speed, using finger to read Poor reading comprehension, avoiding reading
List three assessments for accommodation.
Posture
Range/amplitude
Facility
List three assessments for vergence.
Posture
Range/amplitude
Facility
List five assessments for binocularity.
Stereopsis Suppression Visual acuity differences Fixation Diplopia awareness
List three objective tests of binocularity and what they evaluate.
Cover test - evaluates the alignment in all directions of gaze
Hirschberg test - evaluates alignment and estimates the magnitude of any deviation
Oculo-motility - evaluates versions in all directions to rule out any dysfunction of the EOMs
What are some tests to assess stereopsis?
Stereopsis - titmus ( ͡° ͜ʖ ͡°), fly, randot, fly, frisbee
List 4 tests for suppression.
Worth four dot
Diplopia awareness
Prism doubling
Polarised tests
List the four major factors that stimulate accommodation. Name the primary one.
Blur - primary driver
Proximal awareness
Vergence
Tonic accommodation
Define proximal awareness.
Accommodation based on where the object is in space or where one thinks the object is
Define tonic accommodation.
Occurs from theabsence of any of the stimuli above andreflects baseline neural activity
What can night myopia be considered to come from?
Tonic accommodation
Rate the three states of refractive error (including emmtropes) by their amplitude of accommodation, from highest to lowest.
Myopes > emmetropes > hyperopes (after correction)
Do hyperopes need to accommodate more or less through their glasses? What about myopes?
Hyperopes need to accommodate more
Myopes need to accommodate less
How does luminance affect accommodation (dim light specifically)?
In dim light, the accommodative response is reduced relative to the accommodative demand
What neurological deficit can cause an issue with amplitude of accommodation?
Any 3rd nerve deficit
List an objective assessment for accommodation.
MEM retinoscopy