Visual Field Defects Flashcards
Left Optic Nerve
chiasm
(lose temporal field)
right optic tract (3)
____ is used to assess, diagnose, and monitor
progression of ophthalmologic and neurological conditions
Perimetry
What does the visual sensitivty/threshold depend on? (3)
- age, attention level, refractive statu
- pupil size, media opacity,
- stimulus :size/intensity/color/duration/movement
Kinetic perimetry is ___
seeing motion
when will you see a small dull stimuli?
not until it gets to a fixation point
(as opposed to an elephant you would see immeidately)
static permistery involves
object not moving but going dimmer to birghter
What does confrontation examination involve?
just theexaminer,no standardized method.
Possible strategies:
• use examiner’s face
• finger counting
• finger or hand moving
• palms side by side close to midline 1
(for relative hemianopias) • red object
Pros of confornation visual field exam are:
its inexpensive, fast, practical
Cons of confornation visual field exam are:
its examiner and examinee dependent
General and practical rules of confrontation visual field exam are
examiner is one arm length away, showing the object half that distance
examiner closes contralateral eye
What does an Amsler grid test?
teststhe central 10’ of the VF
• Ptreportsanyarea missing, blurred or distorted
What does tangent screen test?
the central 20 ’of the VF
___ may be used as pseudo static stimuli
tangent screen
What does goldman test
almost the entire visual field
What is the test where the pt faces the bowl and fixates on a peep hole?
What does it measure?
1. Goldman
manualkineticbutcan also do static stimuli; tests almost entire VF. Vary stimulus sizes and intensities.
2. Humphrey Perimeter
automatedstatic, standardized by computer.
Plots blind spot, checks for false positives (sound only) and false negatives (stimulate known seeing area)
Differences between goldman perimeter and humphery perimeter?
Humphery is autonmatic static and standardized by a computer
Goldman is manual kinetic but can do static
depends on examiner
Which test tests for false positives and negatives? How does it do this?
Humphrey
Checksforfalsepositives (sound only) and false negatives (stimulates known seeing area)
Define scotoma
poriton of visual field missing
What is arcuate? What causes it?
arc-shaped scotoma
caused from retinal nerve fiber bundle damage
What is an altiudinal defect?
(superior or inferior defect that respects horizontal meridian) –splits horizontally-
What is a hemianopia?
splits vertically (nasal or temporal defect)
What is a quadranopia?
can’t see a quadrant
Homonymous means the defect is on the ___
same side (“both right visual videals are missing)
Congrous means the defect is
similar in both eyes (not necessary similar side?)
What does heternoymous mean?
defect in different sides eg bitemporal
What is this?
Incomplete right eye temporal hemianopia
What is this?
Relative right eye temporal hemianopia
(relative/absolute is in terms of stimulus)
What is this?
Absolute right eye temporal hemianopia
What devides retina into superior and inferior?
horizontal raphe
What constitutes the nasal-temporal demarcation of the retina?
a vertical line that crosses the fovea
In gluacoma you usually see what focal defect of the retina?
arcuate (flowls the fibers)
Lesion of the optic nerve can cause loss of
visual acuity and color vision
these can be characteristic of a __ lesion
optic nerve
____ retina fibers cross at bottom of chiasm, loop into Wilbrand’s knee
inferior nasal
Sup. Nasal fibers cross at___
the top of the chiasm
Why is the maculo protected from minor lesions of the optic chiasm?
the papillomacular bundle crosses AT THE CENTER OF THE CHIASM
esion at Wilbrand’s Knee looks like
Junctional Syndrome or Ant.
Chiasmal Syndrome = complete loss of one eye
+ sup. field defect in other eye, “pie in the sky”
Lesions beyond the optic chiasm all cause ____ field defects
homonymous (same side, e.g. both right field missing
with retina damage, there might be a decrease in
visual acuity
retina X can have __ or ___ deficits
general or focal
focal correspond to visible lesions
- fovea – central scotoma
- glaucoma – arcuate defect
macular fibers that cross at the optic chiasm do so in the __ and ___ portion
central and posterior
Anterior Chiasmal Syndrome
you get ___ neuropathy
Ipsilateral optic neuropathy: Decrease VA, color vision, RAPD
Anterior Chiasmal Syndrome
you get ___ jundctional scotoma with what sx
Contralateral junctional scotoma with normal VA and color vision
the more posterior in the retrochiasmal visual pathway a lesion is the more ___ it is
congruous
optic tract leads to ___ field deficit
with otpic tract X, ___ is spared
visual acuity
with optic tract X
contralateral ___ and ___ reuslts
contralateral relative afferent pupil defect and hemiparesis (posterior internal capsule)
with lgn damage
VF tend to be ___ and may be incongruous
homonymous
vascular lesions of the ___ may cause a sector defect (SECTORANOPIA)
lgn
damage to?
lgn
typical defect of optic radiations is
homonymous quadrantanopia
anterior lesion of optic raditions affects
meyers loop
anterior lesion of optic radiations at meyers loop
right homonymous incomplete supererior quadrantanopia
different between anterior (meyers loop) and posterior lesion of optic radiation
posteiror lesion does not respect the horizontal meridian
parietal optic radiation field loss is
homonymous inferior visual field deficits
Posterior lobe lesion (central field)___% of the cortex devoted to central 10’ of field !
50
lesions of occitial lobe and visual cortex causes in general
Homonymous Congruous
defects
Anterior lobe lesion: ____ field loss
Monocular
Macular Sparring is common but not exclusive of ____ lobe lesions
occipital
calcarine sulcus field loss
Bilateral homonymous hemianopic central scotomas with macular sparring
caclcaruine sulcus lesion
left occipital lobe (lower)
left parietal
right temporal
