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Flashcards in VF 1 Deck (38):
1

What are the limits of the VF

superior: 60
inferior: 75
temporal: 100
nasal: 60
"TINS"

2

what does the physiologic blind spot correspond to

the optic nerve
-15 deg temporal to the point of fixation
-1.5 degrees below horizontal meridian

3

what connects all point of the same size and brightness

isopter

4

With a 30-2 static perimeter, what are we testing

the central 30 degrees of vision; each point is 6 degrees away from each other.

5

what does a false negative mean on the VF

the patient saw a dimmer light, you present a brighter light and they can't see it, but they should be really able to see it.

6

what does a depression indicate?

generalized reduction in retinal sensitivity

7

what does a scotoma indicate?

focal area of reduced sensitivity surrounded by an area of normal sensitivity
-absolute: defect persists when maximum stimulus is used
-relative: defect present to weaker stimulus, but disappears with brighter stimulus

8

what is lateral to the optic chiasm? what is superior to the chiasm? what is inferior to it?

ICA and cavernous sinus; hypothalamus and floor of the third ventricle; pituitary gland

9

Chiasm usually sits centrally, above the sella turcica, so if we had a pituitary tumor it would affect the chiasm first. But what about a pre fixed or post fixed chiasm? Where would the pituitary tumor affect?

1. pre fixed: chiasm sits in front of the sella turcica, pituitary tumor would affect the optic tract.

2. post fixed: chiasm sits behind the sella, pituitary tumor would affect the optic nerve

10

where does the optic tract extend from?

optic chiasm to LGN; VF will produce homonymous hemianopia

11

what happens in a LGN defect

VF lesions will be homonymous hemianopia

12

Inferior fibers affect your Superior VF, and course through the ____ lobe

temporal

13

Superior fibers affect your inferior VF, and course the _____ lobe

parietal

14

The circle of willis has a dual artery supply. its mainly supported by the ____ ____ artery and gets additional blood supply from the _____ ____ artery

posterior cerebral; middle cerebral; dual vascular supply of visual cortex often results in macular sparing VF defects.

15

Anything affecting the optic chaism and beyond, bc the nasal fibers have cross over you will have ______ vf defect

homonymous (same side) hemianopia (half) VF defect

16

lesions of the optic nerve are typically _____VF loss, invades vertical hemianopic line, may respect the horizontal line, may have complete/partial vision loss. Will almost always have a ____ vision defect, and will almost always have a ____

unilateral; color; RAPD

17

glaucoma is usually cupping without _____

pallor; if you see pallor its typically a different type of optic neuropathy, not glaucoma

18

what are some causes of lesions of the optic nerve

1. optic neuritis
2. trauma
3. space occupying lesion (meningioma)
4. ischemic optic atrophy (NAION, AION)
5. Papilledema
6. Nutritonal/toxic insult
7. Glaucoma

19

chiasmal disease is typically _____, progressive, and bilateral asymmetric. tumors usually don't cause headaches. main cause of chiasmal disease is _____ adenoma. Other causes of chiasmal disease include suprasellar meningioma, _____ aneurysm, or optic nerve glioma

painless; pituitary

20

what are signs of chiasmal disease

1. +/- VA loss
2. VF defect (usually bitemporal)
3. optic atrophy
4. APD
5. dyschromatopsia
6. +/- endocrine dysfunction
7. diplopia: if adjacent cavernous sinus is involved. this is where CN 3, 4, and 6 course through

21

The cause of anterior chiasmal syndrome is usually due to junctional scotoma due to post fixed chiasm (chiasm is posterior to affected sella) which can cause compression of Von Willebrand's Knee due to:

on ipsilateral side you have central 30 degree loss, in contralateral eye you have have superior temporal deficit, thats because of crossing of inferior nasal fibers into opposite optic nerve before going into opposite optic tract

22

What are clinical findings of anterior chiasmal syndrome

1. ipsilateral RAPD (bc that whole nerve has been nicked)
2. +/- diplopia
3. ipsilateral central scotoma
4. contralateral superior temporal defect.

23

What happens in posterior chiasmal syndrome

Chiasm sits anterior to tunica sella, macular fibers cross at posterior chiasm, tumor will impinge on posterior chiasm and optic tracts which causes central bitemporal hemianopia defect because your nasal macular fibers are the most posterior

24

Middle chiasmal syndrome is most common. which is usually due to _____ gland tumors. clinical presentation includes:

bitemporal hemianopia and bilateral optic atrophy because you're compressing the nasal fibers from both eyes

25

what are causes of lateral chiasmal lesions

1. distention of the third ventricle causing pressure on each side of the chiasm
2. ICA aneurysm

26

what are clinical findings of a lateral chiasmal lesion

binasal hemianopia bc you're compressing bitemporal fibers that are coursing through each tract

27

what are associated with chiasmal lesions

1. band pallor
2. diffuse pallor
3. APD
4. dyschromatopsia
5. endocrine dysfunction

28

what are different types of things that happen with endocrine dysfunction

1. acromegaly: prominent brows/nose/chin
2. cushing syndrome: moon face, truncal obesity
3. galactorrhea: making too much breast milk
4. amenorrhea
5. dec libido, infertility

29

how do you manage chiasmal disease

1. MRI with and without contrast
2. neurosurgical referal
3. endocrine workup
4. monitor VF

30

What is typical in post chiasm disease

1. always homonymous (nasal VF of one eye and temporal VF of other eye)
2. congrous
3. Decreased VA is NOT common unless lesion involves optic nerve or occipital lobes
4. Usually due to a cardiovascular disease
5. contralateral APD bc temporal VF is 40% larger than nasal VF.
6. Band opic atrophy: due to crossing of nasal fibers

31

what are causes of optic tract lesions

1. tumors.
2. ischemic stroke
3. aneurysms of superior cerebellar or PCA

32

what are clinical findings of optic tract lesions

1. +/- congrous homonymous hemianopia
2. band optic atrophy
3. contralateral APD.

33

what are causes of lesions of optic radiations

1. vascular lesions
2. primary and secondary tumors
3. trauma

34

what are clinical findings of optic radiation lesions

1. incomplete incongrous quandranopsia
2. neurologic deficits predominate

35

describe temporal lobe lesions

1. incongruous pie in sky
2. affects meyers loop: inferior retinal fibers
3. neurologic symptoms predominate -seizures and hallucinations common

36

describe parietal lobe lesions

1. incongrous pie on the floor
2. affects superior retinal fibers
3. neurologic symptoms predominate

37

describe lesions of the visual cortex

1. strictly visual
2. middle cerebral artery infarct: macular sparing; congruous homonymous hemianopia with no neurologic defects
3. posterior cerebral artery infarct: congrous homonymous macular defect

38

describe lesions of the occipital lobe

1. extreme congruity
2. no neurologic symtoms
3. superior and inferior fibers completely sep and respect for vertical and horizontal midline