NV - Eyelid Disorders - Week 3

Question 1

What muscle forms the eyelid crease?

Answer 1

Levator palpebrae superioris

Question 2

What three factors contribute to eyelid position?

Answer 2

Mechanical aspects of the orbit
Innervation
Anatomical

Question 3

What generally happens to eyelid position with age?

Answer 3

It lowers

Question 4

Define entropion.

Answer 4

Eyelid is turned in

Question 5

Define ectropion.

Answer 5

eyelid is turned out

Question 6

How can entropion be confirmed and what should you look for?

Answer 6

Have the patient squeezze their eyes shut, will cause it to turn further inward
Look for corneal staining from eyelash scratching

Question 7

What would you expect the lid margin to look like with ectropion and why?

Answer 7

Red lower margin due to excessive drying of the conjunctiva

Question 8

How can ectropion be confirmed?

Answer 8

Pull the eyelid downward, then let it retract
If it is slow, or remains stretched out, ectropion is present

Question 9

What is the surgical treatment for entropion and ectropion?

Answer 9

Blepharoplasty

Question 10

What muscle closes the eyelids and what cranial nerve is responsible. Is this the only force responsible for closing the lids?

Answer 10

CN7 activates orbicularis oculi
Also gravity on the tarsus

Question 11

What three muscles are responsible for opening the eyelids? Note the cranial nerve, if applicable (2).

Answer 11

Frontalis muscle CN7
Levator palpebrae superioris CN3
Mullers muscle

Question 12

What kind of information do lid/brow positions and lid crease locations give (2)?

Answer 12

Lid/brow position - information on neural/muscular activity
Lid crease location - identiying common disorders

Question 13

From external appearance, what structure should be clear of the eyelids?

Answer 13

The pupil

Question 14

What is the normal superior lid position and what happens to it with age? What about inferior?

Answer 14

Normal - 11 to 1 o’clock
With age - 10 to 2 o’clock
6 o’clock inferiorly

Question 15

Is scleral show common?

Answer 15

Yes, as long as its symmetric

Question 16

What are three key measures of lid position?

Answer 16

Palpebral fissure
Margin to reflex distance
-superior = MRD1
-inferior = MRD2

Question 17

What is the normal range for palpebral fissure?

Answer 17

9-11mm
-normally 10

Question 18

What are normal MRD1 and MRD2 values?

Answer 18

MRD1 - 4mm
MRD2 - 5 to 6mm

Question 19

What is an abnormal MRD1 value (2)?

Answer 19

≤2mm or
>2mm symmetry between eyes

Question 20

What is the main lid retracting muscle?

Answer 20

Levator palpebrae superioris

Question 21

How is levator palepbrae superioris function measured? What values do you expect to see?

Answer 21

Eye excursion - 45 degrees down from primary gaze
Excursion should be ≥13mm
-typically 15mm, <4mm asymmetry

Question 22

What would you suspect if you do not get normal values for levator paelpbrae superioris function (3)?

Answer 22

Neurological cause (CN3)
Mechanical failure (ligament)
Proptosis

Question 23

What ligament is responsible for the eyelid crease?

Answer 23

Whitnall’s ligament

Question 24

In what percentage of asian eyes is a single crease present and why is this so?

Answer 24

35%
Diffuse lower insertion of whitnalls ligament

Question 25

Why do eyelids droop with age? What is this called?

Answer 25

Whitnalls ligament can stretch/break with age
-dehiscence
-causes loss of LPS function

Question 26

What generally happens as a consequence of LPS function loss and what is a symptom?

Answer 26

Frontalis action keeps the eyes open giving a high brow and high crease
Common cause of headaches

Question 27

Why does the crease rise with loss of LPS function?

Answer 27

Loss of whitnalls ligament and loss of LPS function means the frontalis muscle is used to keep eyes open
Creates a new crease where frontalis inserts

Question 28

List three causes of pseudo-ptosis.

Answer 28

Muscle spasm
Excess skin (dermatochalasis)
Small hypotropia

Question 29

Spasm of what muscle can cause pseudo-ptosis? What can cause this spasm? What is often the trigger?

Answer 29

Orbicularis occuli
Higher order CNS misfiring of CN7 blink-reflex
Trigger is often stress

Question 30

What age and gender does pseudo-ptosis due to muscle spasm often occur?

Answer 30

Middle-aged women

Question 31

What is the management of pseudo-ptosis due to muscle spasm (2)?

Answer 31

Stress management/antidepressants
Botulinum toxin injections around the eye

Question 32

List three differential diagnoses for ptosis if lid deformity is present.

Answer 32

Trauma
Infection/inflammation
Tumour

Question 33

List three differential diagnoses for ptosis if lid deformity is not present.

Answer 33

Congenital
Myopathy
Acquired

Question 34

List three myopathies that can cause ptosis.

Answer 34

Myasthenia gravis
Muscular dystrophy
CPEO

Question 35

What may often casue congenital ptosis and what is it associated with?

Answer 35

Due to aberrant neural innervation
-associated with eye movement anomaly

Question 36

What is the likely cause of ptosis with pupil involvement (2)?

Answer 36

Horners or loss of CN3

Question 37

What does loss of CN3 give (3)?

Answer 37

Total lid closure
Dilated pupil
EOM palsy (down+out)

Question 38

What should you do if you see a down and out eye?

Answer 38

Hospital emergency - possibly intracranial aneurysm

Question 39

What ocular signs would you generally see with horner’s syndrome (2)?

Answer 39

1/3rd eyelid closure and miotic pupil

Question 40

If you see ptosis with pupils involved, is this considered an emergency?

Answer 40

Yes

Question 41

What is duanes retraction syndrome, how many types are there, and what appearance does it cause?

Answer 41

Aberrant innervation of L and M recti
3 types
Gives head tilt due to vertical muscle problem

Question 42

What do all types of duanes retraction syndrome manifest and why?

Answer 42

Retraction of the globe due to bilateral innervation which gives apparent ptosis

Question 43

Does duanes retraction syndrome result in abduction or adduction?

Answer 43

Adduction

Question 44

Why does head tilt occur in duanes retraction syndrome?

Answer 44

Excess innervation to contralateral vertical muscles on adduction

Question 45

Describe each type of duanes retraction syndrome (3, 1, 2).

Answer 45

Type 1 - narrowing, limited abduction, vertical uscle overshoot
Type 2 - limited adduction
Type 3 - limited abduction with vertical muscle undershoot