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Ocular Disease III > Diplopia > Flashcards

Flashcards in Diplopia Deck (41):
1

what are some signs of EOM dysfunction when its closer to the orbit

1. proptosis
2. congestion
3. maybe optic nerve swelling/pallor

2

where do superior, inferior, medial, and recti muscles originate from

annulus of zinn

3

what are the tertiary actions of the oblique muscles

abduction

4

what are the tertiary actions of the recti muscles

adduction

5

_____ law of innervation explains binocular coordination of eye movements. Paired agonist muscles from each eye operating in the same field of action receive equal innervation

herings

6

____ law of reciprocal innervation is when a muscle contracts, its direct antagonist will relax to an equal extent to allow for smooth movement

sherrington's

7

explain what happens in convergence retraction nystagmus in parinaud's syndrome

pt is trying to look up, but there is anamalous firing to the MR and they get nystagmus

8

What types of eye movements are your EOMS involved in

1. saccades
2. pursuits
3. VOR
4. OKN

9

In ______ lesions, the 3rd nucleus and fascicle and nerve are still intact, which means VOR and OKN will still be functioning.

supranuclear; in cortex --> directs actions of the ocular motor nerves

10

Describe the pathway of vertical saccades

FEF sends projection to Superior Colliculus --> rIMLF and interstitial nucleus of Cajal which are in midbrain--> vertical saccades

11

which CN's are in charge of vertical eye movements

3 and 4

12

where are horizontal saccades done? whats the pathway?

pons

FEF -->PPRF excites CN 6 nucleus --> signal to contralateral CN 3 via MLF

13

T/F PPRF is responsible for generating saccades, not pursuits

true

14

Describe pursuits pathway

FEF --> pontine nuclei --> contralateral cerebellum

15

defective pursuits may be a lesion in what parts of the brain>

1. FEF
2. pontine nuclei
3. cerebellum

16

which lesions will ALWAYS have impaired VOR and OKN

1. nuclear
2. fascicular
3. peripheral nerve

17

diplopia occurs due to ______ phoria, or acquired EOM limitation, due to a nerve palsy or a restrictive defect, gaze palsies, NMJ problems, or orbital disease

decompensated (CI, DI, CE, DE)

18

what are some characteristics of diplopia due to a decompensated phoria

1. intermittent diplopia
2. horizontal diplopia
3. no neurologic symptoms
4. full range of EOM's
5. deviation is comitant
6. decreased horizontal fusional ranges
7. may have intermittent tropia

19

_____ convergence spasm is usually due to intermittent diplopia, blurred vision at distance due to spasm of accommodation, more prevalent in young women, and can mimic bilateral CN _____ palsy. This is due to a spasm of the near reflex.

primary; 6

20

what are signs of convergence spasm

1. pseudo myopia that resolves with cycloplegia
2. variable esotropia
3. limited abduction
4. pupillary miosis
5. NORMAL abducting saccades
6. Intact abduction with VOR and normal DUCTIONS

21

What are the four diplopia questions to ask

1. Does the double vision go away when either eye is covered
2. Is the double vision horizontal or vertical?
3. Is the double vision greater at distance or near?
4. Is the double vision greater in the left or right gaze?

22

what are common causes of monocular diplopia

1. uncorrected RE
2. corneal irregularity/scarring
3. lens change/subluxation
4. tear film abnormality
5. polycoria
6. maculopathy

23

horizontal diplopia can be caused by:

1. CI
2. DI
3. III palsy
4. VI palsy
5. INO
6. MG
7. Thyroid associated problems

24

vertical diplopia can be caused by:

1. III palsy
2. IV palsy
3. Thyroid associated problems
4. MG
5. Skew deviation (in midbrain)

25

if double vision is worse at distance which muscles are we concerned about

1. divergers
2. elevators

* opposite if double vision is worse at near

26

What are signs of ocular misalignment

1. face turn (Dwaynes)
2. Head tilt - in 4th nerve palsy, in direction opposite of palsy
3. eye closure
4. depressed/elevated chin

27

when will people not report diplopia even if there is ocular misalignment

1. high RE (amblyopia develops
2. cataract
3. optic nerve/retinal disease ( no vision in that eye)
4. longstanding childhood strabismus
5. ptosis

28

What are causes of Internuclear lesions in binocular diplopia


-Gaze palsies
-INO
-BINO
-WEBINO
-One and half syndrome
-Skew deviation

29

T/F in intERnuclear lesions you still have VOR

true

30

T/F, an isolated 6th nerve palsy occurs from a nuclear lesion

False; close association with PPRF --> will always result in a gaze palsy

31

where do nuclear lesions occur

in brainstem; cranial nerves 3, and 4

32

where do infra nuclear lesions occur

1. CN III
2. CN IV
3. CN VI
4. NMJ
5. mechanical EOM restriction due to orbital disease

33

what do you look for while your evaluating your pt that complains of diplopia

1. misalignment, ptosis, pupillary abnormality
2. evaluate ductions
3. evaluate versions
4. evaluate vergence
5. evaluate pursuits and saccades
6. evaluate VOR
7. assess direction and amount of ocular misalignment
8. look for head tilt/turn/chin position
9. orbital signs (proptosis)
10. perform forced auction when indicated

34

Isolate paretic muscle in horizontal diplopia by:

maddox rod
1. crossed diplopia: red line is to the left; medial rectus isn't working
2. uncrossed diplopia: red line is to the right; lateral rectus isn't working

35

How do you know which eye the deviation is when performing the maddox rod test

look at which gaze the deviation is worse

36

While performing maddox rod test, on left gaze, the eso deviation is even worse. what does this mean

the left LR is affected

37

in _______, the eye sees the lower image

hypertropia

38

what test do we do if only 1 muscle is involved

parks 3 step

39

what are the steps in parks 3

1. identify the hypertrophic eye in primary gaze
2. determine if hypertropia increases in right/left gaze
3. determine if hypertropia increases on right or left head tilt

40

what are limitation to parks 3 step

1. multiple muscles involved
2. doesn't work in cases of mechanical restriction of eye muscles
3. patient is sitting or standing

41

what does the double maddox rod test determine

presence and quality of cyclodeviation