Eyelids Flashcards
Eyelids anatomy
- Skin
- Orbicularis oculi
- Fibrous layer
- Levator palpebrae superioris muscle
- Müller muscle
Sensory supply to eyelid skin
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)
Pathways in blinking reflex
Corneal stimulus: CNV1 (afferent), CNVII (efferent)
● Light stimulus: CNII (afferent), CNVII (efferent)
● Auditory stimulus: CNVIII (afferent), CNVII (efferent)
What is Bell’s phenomenon?
A physiological term referring to the upward and outward rotation of the globe on forced lid closure.
What is a Chalazion?
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.
Management of a Chalazion
Mainly with hot compresses twice daily and use of oral antibiotics if infected. Incision and curettage is also an option
Port wine stain details?
Pink/purple
Don’t blanch
Don’t cross midline
Occur along distribution of choroidal neovascularisation
What is a sebaceous gland carcinoma?
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.
What is Trichiasis?
Eyelashes growing wrong way i.e towards the cornea or sclera
Causes of Trichiasis?
Herpes Zoster Ophthalmicus
Blepharitis
What is Distichiasis
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.
Types of blepharitis
Anterior - skin around base of eyelashes irritated
Posterior - Inflammation of the meibomiam gland around the eyelid margins due to gland dysfunction
Causes of anterior and posterior blepharitis
Anterior - Staph or seborrheic
Posterior - Rosacea
Treatment of blepharitis
- 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
Causes of Ptosis
Horner syndrome
CNIII palsy
Myasthenia Gravis
Age related
Congenital (failure of levator muscle to develop)
Psuedoptosis causes
Dermatochalasis - excessive skin in eyelid
Blepharochalasis - Abnormal elastic eyelids causing oedema. Leads to skin stretch and atrophy with subsequent folds and ptosis.
Causes of lid retraction
- 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)
What is Lid coloboma?
Incomplete development of the eyelid due to the failure of lid fold fusion. It can
occur in either the upper or lower eyelids
What are the two types of Coloboma?
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
Tell me about Stye
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
