Oculoplastics

Question 1

Ptosis

Answer 1

Drooping of the upper eyelid

Question 2

Ptosis (diagnosis)

Answer 2

• upper lid covers more than 2mm (1/6) of cornea
• narrowing of vertical palpebral fissure

Question 3

Mullers muscle

Answer 3

• sympathetically innervated
• contributes to 50% of lid raising
• maintains elevation of upper eyelid

Question 4

Pseudoptosis

Answer 4

• looks like a ptosis, but no lid abnormality and something else is causing it
• e.g. enophthalmos, dermatochalesis

Question 5

Types of Congenital ptosis

Answer 5

• myogenic
• neurogenic

Question 6

Myogenic ptosis

Answer 6

• majority caused by deficiencies of levator muscle
• absent/or weak lid crease depending on function of levator muscle (partial/no function)
• levator stiffness - won’t allow lid to lower properly, may not be able to close eyes fully
• levator muscle controls 85% of lid raising
• runs above SR, both supplied by CN3

Question 7

Myogenic ptosis - SR dysfunction

Answer 7

• combined levator + SR dysfunction - eye also can’t raise alongside lid
• Bell’s phenomenon - eye automatically rotates upwards when lids come down - protective mechanism for cornea

Question 8

Myogenic ptosis - BPES

Answer 8

• blepharophimosis - decrease in palpebral aperture
• ptosis
• epicanthus inversus - skin fold running from upper to lower lid
• telecanthus - increases space between medial canthi

Question 9

Neurogenic ptosis - Marcus Gunn jaw winking syndrome

Answer 9

• abnormal connection between nerve endings and between CN3 & CN5
• levator innervated by CN5 instead of CN3
• muscles that normally involved in mouth movement innervate lid also, when mouth goes up so does lid

Question 10

Congenital Horner’s syndrome

Answer 10

• disruption in sympathetic innervation, sympathetic nerve supplies horner’s muscle (involved in 15% of lid raising)
• results in mild ptosis
• sympathetic muscle also supplies pupil - associated miosis
• hyperpigmentation of affected iris leads to heterochromia (iris colours different) - not present in acquired horner’s

Question 11

Congenital ptosis - visual function

Answer 11

• amblyopia in 20%
• due to ptotic lid obscuring visual axis, anisometropia, high astigmatism, strabismus

Question 12

Acquired ptosis types

Answer 12

• aponeurotic ptosis
• acquired myogenic ptosis
• acquired neurogenic ptosis
• traumatic ptosis
• mechanical ptosis

Question 13

Aponeurotic ptosis

Answer 13

• most common acquired ptosis
• usually age related
• thinning or disinsertion of the levator aponeurosis into the tarsal plate and into the skin

Question 14

Aponeurotic ptosis - features

Answer 14

• thinning of upper lid, deep sulcus
• higher than normal upper lid crease (>8-10mm)
• normal levator function
• eyelid drop on extreme downgaze

Question 15

Acquired myogenic ptosis

Answer 15

• ptosis caused by a muscular issue
• defining feature - reduced levator function
• at the level of the muscle - myotonic dystrophy, chronic progressive external ophthalmoplegia (CPEO)
• at the level of the myoneural junction - myasthenia gravis, ocular myasthenia

Question 16

Acquired myogenic ptosis - muscular dystrophies (myotonic dystrophy)

Answer 16

• bilateral symmetrical progressive ptosis not often seen in children
• autosomal dominant
• Christmas tree cataract
• myopathic facies (characteristic facial appearance)
• cardiac conduction abnormalities

Question 17

Acquired myogenic ptosis - muscular dystrophies (CPEO)

Answer 17

• bilateral progressive ptosis
• affects levator muscle and all EOM’s
• px can’t look up, down, left, right
• but very slow progressing so px can learn to move head
• pigmentary retinopathy
• cardiac conduction abnormalities

Question 18

Acquired myogenic ptosis - level of myoneural junction (Myasthenia gravis)

Answer 18

• autoimmune disorder
• fluctuating ptosis, often with diplopia
• worsens when px looks up
• rest/sleep improves ptosis
• life threatening symptoms - dysphasia (trouble swallowing) and dyspnoea (trouble breathing)
• myasthenia must be considered in every case of ptosis

Question 19

Acquired neurogenic ptosis - 3rd CN palsy

Answer 19

• 3rd CN supplies levator muscle, SR, IR, MR, IO
• ptosis but also…eyeball down and out, only abduction (LR) and intorsion (SO) movements present
• pupil may be involved
• accommodation may be absent

Question 20

Acquired neurogenic ptosis - 3rd CN palsy (vasculopathic causes)

Answer 20

• something interrupting blood supply
• px normally has hx of DM, HBP or atherosclerosis
• palsy’s - sudden onset
• pupil sparing
• recovery within 3-6 months

Question 21

Acquired neurogenic ptosis - 3rd CN palsy (compressive causes)

Answer 21

• more concerning
• aneurysm
• neoplasm
• total or partial
• progressive symptoms
• pupil involved
• emergency workup

Question 22

Acquired neurogenic ptosis - acquired horner’s syndrome (oculosympathetic palsy)

Answer 22

• abnormality of horner’s muscle which is supplied by sympathetic output (only supplies 15% of lid raising)
• ptosis is mild
• although miosis present due to sympathetic innervation, normal pupil reactions
• enophthalmos present - ???
• also a lack of sweating - supplied by the sympathetic nerve

Question 23

Acquired neurogenic ptosis - acquired horner’s syndrome (causes)

Answer 23

• intracranial aneurysm/tumour/inflammation
• tumour along sympathetic pathway
• have to image lung, as lung tumours can also cause acquired horner’s and carotid aneurysms

Question 24

Traumatic ptosis

Answer 24

Often follows an orbital injury

Question 25

Mechanical ptosis

Answer 25

- something weighing lid down - very difficult to keep lid raised - e.g. a chalazion

Question 26

Measurements in Ptosis

Answer 26

- Palpebral fissure height - Marginal reflex distance - Upper lid crease and fold - Levator excursion - Lid show

Question 27

Measurements in Ptosis - Palpebral fissure height

Answer 27

- vertical distance between 2 lids

Question 28

Measurements in Ptosis - Marginal reflex height

Answer 28

- Distance between pupillary light reflex (when you shine a light in the px's eye) and lid margin - Type 1 - between light reflex and upper lid margin - Type 2 - between light reflex and lower lid margin

Question 29

Measurements in Ptosis - Excursion of Levator function

Answer 29

- Ask px to look down - Lift their brow up so frontalis cannot cloud any readings taken - Position a ruler so that its bottom end is at the level of the lid as the px looks down (not on lid, just in front of lid) - Ask px to look up and record how far lid has moved up on ruler (don't move ruler) - Normal - 15mm - Good - >8mm - Fair - 5-7mm - Poor - <4mm

Question 30

Surgical Management

Answer 30

- Dependent on levator function - Good - mullers muscle conjunctival resection - Good/moderate - levator aponeurosis advancement - Moderate/poor - levator resection - Poor/absent - frontalis brow suspension

Question 31

Surgical Management - Mullers muscle conjunctival resection

Answer 31

- Shorten a portion of the mullers muscle (which sits underneath the levator aponeurosis) as well as some of the conjunctiva because the mullers muscle lies just above the conjunctiva - Minimally invasive

Question 32

Surgical Management - Levator aponeurosis advancement

Answer 32

- Isolate the levator aponeurosis - Once found we can shorten the levator aponeurosis or strengthen it with sutures to the tarsal plate (has the desired effect of pulling up the lid)

Question 33

Surgical Management - Levator resection

Answer 33

- shorten both aponeurosis and mullers muscle

Question 34

Surgical Management - Frontalis brow suspension

Answer 34

- Connect frontalis muscle to tarsal plate via a sling - Child < 4 years old - use an artificial suture (e.g. proline) - Child > 4 years old - take fascia lata from thigh (need to be over 4 as they must have 15cm of fascia lata), cut into strips, run strips going down forehead into lid, when child lifts brow they also lift lid with it