Visual Field Deficits Flashcards
If an object is in the left visual field, where is this projected on a person’s retinas?
nasal left retina
temporal right retina
If an object is in way out in the periphery, where does this project on a retina?
nasal retina of same side eye
Which axons cross in the optic chiasm?
nasal retinal axons
What is an anopsia?
large visual field deficit
What is a scotoma?
small visual field deficit
What does homonymous mean?
defect is on same side in both eyes
example: temporal on right and nasal on left
What are two words that are more commonly used instead of heteronymous?
bitemporal or binasal
What does congruous mean? incongruous?
congruous - defect is similar in both eyes
incongruous - defect is different in both eyes
How would visual fields be affected by damage to the left optic nerve?
complete blindness in left eye
How would visual fields be affected by damage to the middle of the chiasm?
peripheral loss in both eyes
bitemporal field defect
How would visual fields be affected by damage to the right optic nerve, just anterior to the chasm?
Vision loss in right eye and a sector of the left eye visual field because of willebrand’s knee (looks like a “pie in the sky” in the left eye”
Describe the visual field deficits usually produced by lesions to the lateral geniculate?
homonymous and may be incongruous
-vascular lesions - most common tend to cause a sector defect - sectoranopia
How would visual fields be affected by damage to the left lateral geniculate ?
congruous right homonymous horizontal sectoronopia
How would visual fields be affected by damage to a temporal lobe?
homonymous superior incomplete (contralateral)
double pie in the sky
What is meyer’s loops?
optic radiations that loop into the temporal lobe as they head to the occipital lobe
How would visual fields be affected by damage to a parietal lobe?
homonymous inferior (contralateral) -tend to be more congruous than temporal lobe lesions
How would you describe lesions in the occipital lobe?
homonymous and congruous and usually have macular sparing (central vision is spared)
What would occur if there was a lesion to the posterior occipital lobe?
loss of vision in the central field
How would visual fields be affected with a left upper bank lesion in the occipital lobe?
right homonymous inferior quaternopia
with macular sparing
How would visual fields be affected with a lower bank lesion in the left occipital lobe?
right homonymous superior quaternopia with macular sparing
How is a kinetics perimetry test performed?
test light moved towards center of vision from periphery until patient can detect it
How is static perimetry performed?
a dim light is presented at a certain location than made brighter until it is seen
What visual field test is inexpensive, fast, practical, and there is no standardized way of conducting it?
confrontation
What visual field test can the patient bring home and use to see if they have blurriness or distortion in their visual field?
amsler grid
Which part of the visual field does a tangent screen test for?
central 20 degrees of visual field
Which two visual field tests are manual and kinetic?
tangent screen and goldmann perimeter
What part of the visual field does the goldmann perimeter test?
entire visual field almost
Which test is automated static perimetry?
humphrey perimeter
What is an arcuate?
arc like shape defect produced by retinal nerve fiber bundle damage
What word describes either a superior or inferior defect that respects the horizontal median?
altitudinal
What word describes a nasal or temporal defect that splits vertically?
hemianopia
What kind of defect occurs in glaucoma?
arcuate
Where do macular fibers cross in the optic chiasm?
centrally and posterior
Beyond the optic chiasm lesions tend to be___
homonymous
The more posterior in the pathway that a lesion occurs, the defects tend to be ____
more congruous
