Term
| What are the 6 characteristics of NBV? |
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Definition
-accurate monocular fixation in each eye
-normal VA in each eye
-integrated neuromuscular control of IOMs/EOMs
-sensory correspondence about the 2 foveas
-similarity of final ocular images
-sensory unification of the 2 ocular images |
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Term
What anomalies are associated with accurate monocular fixation?
When does this condition occur?
What anomalies are associated with normal VA in both eyes?
What anomalies are associated with integrated neuromuscular control of EOMs/IOMs?
When do these problems typically start?
Where is the lesion in INO? What test is done in this condition?
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Definition
-eccentric fixation
-under monocular conditions only
-amblyopia
-abnormal version, INO, strabismus, abnormal AC/A
-90% before age 5
-medial longitudinal fasciculus; oculocephalic reflex |
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Term
What anomalies are associated with sensory correspondence about the 2 foveas?
What finding might you see in ARC?
What anamolies are associated with the final ocular images from each eye?
What causes this condition? |
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Definition
-ET, XT, ARC
-may provide some form of binocular vision in children with the condition
-aniseikonia- expansion/compression of the photoreceptors |
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Term
What anomalies are associated with sensory unification of the 2 ocular images (sensory fusion)?
When does fusion develop? |
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Definition
-lack of fusion resulting from suppresion
-few before 8 weeks of age and most between 12-16 weeks of age; onset of stereopsis approximately at 15 weeks of age and rate of stereoacuity is rapid with the infanct becoming 30 sec-100 sec by 40 weeks |
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Term
What are the 4 components of Sensory Fusion?
Which 2 are not fusion? |
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Definition
-simultaneous perception
-superimposition
-fusion
-stereopsis
-simultaneous perception and superimposition |
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Term
What is simultaneous perception?
Superimposition?
Fusion?
Stereopsis? |
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Definition
-ability to see 2 images, one formed on each retina simultaneously (not superimposed)
-abilty to correlate the 2 dissimilar images, one formed on each fovea, and to superimpose them
- the ability to see 2 similar images, one formed on each fovea, and to blend them as one
-the ability to perceive 2 similar and slightly disparate images, one formed on each retina, and to blend them as one |
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Term
| Worth's Grades of Fusion correspond to what? |
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Definition
-superimposition- 1st degree
-fusion- 2nd degree
-stereopsis- 3rd degree |
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Term
What is bifoveal/central fusion?
What is peripheral fusion?
What do you expect the stereopsis to be if any? |
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Definition
-fusion of images from the fovea of each eye (>/= 60 sec of arc)
-fusion of images from each eye for retinal areas outside of the fovea/macula, with one fovea being suppressed (will have reduced stereopsis if any)
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Term
| Describe the pyramid of binocular vision. |
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Definition
| -sensory --> integrative --> motor |
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Term
What are the sensory processes/anomalies associated with BV problems?
What are the anomalies? (5) |
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Definition
-anatomical and physiological activities involved in the collection and transmission of visual info to the cortex
-ametropia, amblyopia, eccentric fixation, acc dysfunction, ocular disease |
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Term
What are the integratice processes associated with BV problems?
What are the anomalies? |
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Definition
-those anatomical, physiological, and psychological activities involved in the fusion and synthesis of the 2 cortical images to form a single binocular percept
-suppresion, ARC, horror fusions, aniseikonia |
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Term
What are the motor processes/anomalies associated with BV problems?
What are the anomalies? |
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Definition
-those anatomical, physiological, and psychological activities necessary for proper alignment of the eyes at all usual distances and directions of gaze
-strabismus, heterophoria, abnormal fusional vergences, fixation disparity, nystagmus |
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Term
What are the 8 treatment options?
How much ground in prism should be used?
How much fresnel prism can be used?
Which eye do you use the fresnel prism on? |
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Definition
-RE, occulsion, added lenses, prism, orthoptics/VT, pharmacological agents, EOM surgery, botulinum toxin
-no more than 7-8 D per lens
-up to 30 PD in each lens
-before the non-dominant/affected eye |
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Term
Under what circumstances are Fresnel prisms used? (5)
What are some problems with Fresnel prism? |
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Definition
-in pts in whom the diplopia is likely temporary
-in pts who require a larger prism power
-an initial trial, to asses effectiveness of prism txt
-uncertain about how mcuh prism to Rx
-cost considerations
-reduced VA, chromatic dispersion, reduced contrast, scattering of light |
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Term
What are the guidelines for how mcuh prism to Rx?
XT?
ET?
Hyper/Hypo?
*less prism is always better |
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Definition
-1/3 of total deviation
-close to full amt of deviation
-close to full amt of deviation |
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Term
Can Orthoptics/VT teach a patient to fuse?
What are the prerequisites for EOM sx? |
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Definition
-no, can only help patients that already have the ability to fuse
-accurate refraction, minimal or no amblyopia, and a stable deviation over time |
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Term
What are the guidelines for EOM Sx?
ET?
XT?
Hyper/Hypo?
Will pediatric strabismus have residual effects after ex? |
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Definition
- >/= 15 PD in primary
- >/= 20 PD in primary
- >/= 10 PD in primary
-yes |
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Term
How does botulinum toxin work?
When does treatment become effective and how often does it need to be retreated?
What are the common complications of botulinum toxin txt? |
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Definition
-blocks release of ACTH into synaptic cleft (temporary chemical denervation)
-3 days, maximal until 6 weeks, and complete recovery at 3 months
-ptosis and vertical deviation |
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