Diplopia

Question 1

How does monocular diplopia resolve?

Answer 1

With pinhole

Question 2

If you cover one eye and the diplopia resolves…

Answer 2

Binocular diplopia -

1) Innervational misalignment
2) Mechanical misalignment

Question 3

When do you see the maximum separation of images?

Answer 3

Position of gaze where the muscle is the weakest or most restricted. (left 6th N palsy, worse in left gaze)

Question 4

CN4 palsy - head tilt

Answer 4

RIGHT 4 - head tilts to LEFT

LEFT 4 - head tilts to RIGHT

Question 5

What conditions mimic blepharoptosis (eye lid ptosis)

Answer 5

1. Hypotropia (lookin down close other eye, will look up)
2. contralateral lid retraction seen in graves disease
3. Dermatochalasis - loose skin
4. Brow ptosis seen in bell’s palsy

Question 6

What causes true ptosis

Answer 6

1. congenital
2. CN3
3. Horners
4. Myesthenia gravis

Question 7

symmetric misalignment in all positions of gaze is called

Answer 7

Comitant
Childhood strabismus
Chronic innervational disease

Question 8

Asymmetric mislignment greatest in position of most affected muscle

Answer 8

Incomitant
Innervational or
Mechanical

Question 9

Examples of mechanical causes of incomitant binocular diplopia

Answer 9

Orbital fracture

Graves disease

Question 10

Examples of innervation causes of incomitant binocular diplopia

Answer 10

1. Stroke, brainstem
2. cn 3,4, 6 PALSY
3. internuclear opthalmoplegia
4. myesthenia gravis

Question 11

Graves disease - what happens

Answer 11

Accumulation of glucosaminoglycans in INFERIOR RECTUS and MEDIAL rectus - become thickened and pull eye down or in

Question 12

Acquired conditions of cranial nerve palsies

Answer 12

1. Ischemia
2. tumor
3. Demylination
4. Trauma
5. metabolic - thymine deficiency
6. Myesthenia gravis

Question 13

What is myesthenia gravis

Answer 13

Antibodies to Nicotinic acetylcholin receptors
- fatiguability -
IMITATOR - PUPIL NOT INVOLVED!!

Question 14

What do you see in a patient with a 6th nerve palsy

Answer 14

1. Esodeviation (eye is in)
2. Horizontal diplopia
3. Ischemia (hypertension/diabetes)
   EXCLUDE INCREASE ICP. PAPILLEDEMA

Question 15

6th nerve palsy can be a….

Answer 15

FALSE localizing sign -
it is subject to compression
e.g. subcranial hemorrhage

Question 16

Features of CN4 palsy

Answer 16

1. hYPERtropia - affected eye - look up
2. Head tilts to opposite side
3. Positive 3 step test?
4. Vertical/diagonal diplopia

Question 17

Causes of CN4 palsy

Answer 17

1. TRAUMA most common
2. Congenital
3. Ischemia (diabetes hypertension)
4. RARELY TUMORS OR ANEURYSM

Question 18

when you tilt your head to the right

Answer 18

Right eye INCYCLOTORTS

Left eye excyclotorts

Question 19

3 step test for SO - straight ahead gaze, lateral gaze

Answer 19

1. Straight ahead, bad eye hypertropes
2. Lateral gaze (OPPOSITE to affected eye) WORSE - unaffected inferior oblique - hypertrope
3. Head tilt to affected side - overactive superior rectus - worse

Question 20

When is the pupil spared in 3rd nerve palsy

Answer 20

Likely MICROVASCULAR ischemia - central

If pupil is involved - THINK PCOM -

Question 21

Aneurysm of the pcom is like a

Answer 21

3rd nerve pupil bomb

Question 22

A medial rectus palsy is not necessarily a Partial 3rd nerve palsy! no think of something else

Answer 22

1. Internuclear opthalmoplegia

2. Myesthenia gravis

Question 23

Orbital apex syndrome -

Answer 23

1. RAPD if optic nerve is compressed

2. 3,4,6 palsy

Question 24

A carotid cavernous sinus fistula

Answer 24

can cause 6th cranial nerve palsy

Question 25

Pituitary apoplexy -

Answer 25

1. CN3 palsy - no pupil affected | 2. Bitemporal hemianopsia

Question 26

Which two conditions are least likely to present with loss of vision and binocular diplopia?

Answer 26

1. 3rd nerve palsy and pcom aneurysm | 2. Myesthenia gravis

Question 27

Which 3 conditions CAN cause double vision and loss of vision

Answer 27

1. OPTIC NEURITIS 2. pituitary apoplexy 3. Giant cell arteritis

Question 28

In giant cell arteritis what is high?

Answer 28

platelets ESR CRP

Question 29

In strabismus surgery a recession will

Answer 29

weaken the muscle decrease tension | recess antagonis muscle... less double vision

Question 30

When do you perform a strabismus surgery

Answer 30

After 12 months

Question 31

Botox to right lateral rectus if they have 6th nerve palsy

Answer 31

IS not GOOD - botox relaxes the muscle - | make it WORSE - need to weaken the antagonist muscle - like medial rectus