Eyelids

Question 1

Eyelids anatomy

Answer 1

1. Skin
2. Orbicularis oculi
3. Fibrous layer
4. Levator palpebrae superioris muscle
5. Müller muscle

Question 2

Sensory supply to eyelid skin

Answer 2

Lateral upper eyelid: Lacrimal nerve (CNV1).
● Upper eyelid: Supraorbital and supratrochlear nerves (branches of frontal nerve of CNV1).
● Medial canthal area: Infratrochlear nerve (branch of nasociliary nerve of CNV1).
● Lower eyelid: Infraorbital nerve (CNV2)

Question 3

Pathways in blinking reflex

Answer 3

Corneal stimulus: CNV1 (afferent), CNVII (efferent)
● Light stimulus: CNII (afferent), CNVII (efferent)
● Auditory stimulus: CNVIII (afferent), CNVII (efferent)

Question 4

What is Bell’s phenomenon?

Answer 4

A physiological term referring to the upward and outward rotation of the globe on forced lid closure.

Question 5

What is a Chalazion?

Answer 5

A sterile lipogranuloma that occurs due to obstruction of the meibomian glands and occasionally the gland of Zeis.

Presents as a painless nodule in the eyelid.

Question 6

Management of a Chalazion

Answer 6

Mainly with hot compresses twice daily and use of oral antibiotics if infected. Incision and curettage is also an option

Question 7

Port wine stain details?

Answer 7

Pink/purple
Don’t blanch
Don’t cross midline
Occur along distribution of choroidal neovascularisation

Question 8

What is a sebaceous gland carcinoma?

Answer 8

This tumour arises from meibomian glands or, less commonly, glands of Zeis. On histopathology, foamy vacuolated lipid containing cytoplasm with hyperchromatic
nuclei are seen. They are more common in elderly females and appear as a yellow
nodule in the upper eyelid which may be mistaken for a chalazion.

Question 9

What is Trichiasis?

Answer 9

Eyelashes growing wrong way i.e towards the cornea or sclera

Question 10

Causes of Trichiasis?

Answer 10

Herpes Zoster Ophthalmicus

Blepharitis

Question 11

What is Distichiasis

Answer 11

Refers to the formation of a posterior row of eyelashes. This may be congenital
(AD inheritance) or acquired from chemical injury, Stevens-Johnson syndrome
or ocular cicatricial pemphigoid.

Question 12

Types of blepharitis

Answer 12

Anterior - skin around base of eyelashes irritated

Posterior - Inflammation of the meibomiam gland around the eyelid margins due to gland dysfunction

Question 13

Causes of anterior and posterior blepharitis

Answer 13

Anterior - Staph or seborrheic

Posterior - Rosacea

Question 14

Treatment of blepharitis

Answer 14

• Eyelid hygiene is the most important management.
• Antibiotics (e.g. tetracyclines, due to their ability to inhibit fatty acid oxidation and lipase production).
• Tea tree oil may be used for demodex infestation

Question 15

Causes of Ptosis

Answer 15

Horner syndrome

CNIII palsy

Myasthenia Gravis

Age related

Congenital (failure of levator muscle to develop)

Question 16

Psuedoptosis causes

Answer 16

Dermatochalasis - excessive skin in eyelid

Blepharochalasis - Abnormal elastic eyelids causing oedema. Leads to skin stretch and atrophy with subsequent folds and ptosis.

Question 17

Causes of lid retraction

Answer 17

• Graves ophthalmopathy
• Parinaud syndrome (Collier sign)
• Third nerve misdirection
• Marcus Gunn jaw-winking syndrome
• Progressive supranuclear palsy
• Down syndrome
• Congenital hydrocephalus (setting-sun appearance: bilateral downward deviation of the globes with upper lid retraction)

Question 18

What is Lid coloboma?

Answer 18

Incomplete development of the eyelid due to the failure of lid fold fusion. It can
occur in either the upper or lower eyelids

Question 19

What are the two types of Coloboma?

Answer 19

Upper eyelid - Forms at the junction of the middle and inner thirds of the upper eyelid. Can be associated with Goldenhar syndrome.

Lower eyelid - Forms at the junction of the middle and outer thirds of the lower eyelid. Can be associated with Treacher Collins syndrome

Question 20

Tell me about Stye

Answer 20

External hordeolum is an infection of the glands of Zeis or Moll. Internal hordeolum is an infection of the meibomian gland. It is usually due to a staphylococcal infection and presents as a painful, erythematous swelling of the eyelid. Management includes hot compresses, topical antibiotics and eyelid hygiene