Eyelids Flashcards
3 layers of eyelid skin
epidermis
dermis
skin adnexa
what do the skin adnexa include (lie deep in the dermis)
eyelashes
glands (eccrine, apocrine, holocrine)
example of eccrine glands
sweat glands
example of apocrine glands
modified sweat glands (e.g. gland of Moll)
2 examples of holocrine glands
gland of Zeis
meibomian glands
secrete/synthesise lipids and oily substances
sensory supply to lateral upper eyelid
lacrimal nerve (CNV1)
sensory supply to upper eyelid
supraorbital and supratrochlear nerves (branches of frontal nerve of CNV1)
sensory supply to medial canthal area
infratrochlear nerve (branch of nasociliary nerve of CNV1)
sensory supply to lower eyelid
infraorbital nerve (CNV2)
what type of muscle is orbicularis oculi
striated
4 parts of orbicularis oculi
palpebral
orbital
lacrimal
ciliary
nerve supply to orbicularis oculi
tempral and zygomatic branches of CNVII
2 things the fibrous later of the eyelid consists of
tarsal plates - provide structural support, upper tarsal plate thicker than lower
orbit septum
function of levator palpebrae superioris
striated muscle responsible for eyelid retraction - originates at lesser wing of sphenoid to insert into tarsal plate
nervous supply of levator palpebrae superioris
superior division of CNIII
function of Müller muscle
smooth muscle, sympathetic nervous system, contributes to eyelid retraction - originates from aponeurosis of levator to insert into tarsal plate
3 pathways which activate the blinking reflex
corneal stimulus - CNVI (afferent), CNVII (efferent)
light stimulus - CNII (afferent), CNVII (efferent)
auditory stimulus - CNVIII (afferent), CNVII (efferent)
what is Bell’s phenomenon
upward and outward rotation of the globe on forced lid closure - obvious in those with CNVII palsy as the lid remains open when patients are asked to close their eyes
what is a chalazion
sterile lipogranuloma due to obstruction of meibomian glands/sometimes gland of Zeis
2 conditions associated with chalazion
blepharitis
acne rosacea
3 ways to manage a chalazion
hot compresses twice daily
oral antibiotics if infected
incision/curettage
what is a port wine stain (naevus flammeus)
congenital capillary malformation of the dermis
how does a port wine stain present
pink/purple well-demarcated patches that don’t blanch on pressure
never cross the midline
typically occur along the distribution of choroidal neovascularisation (CNV)
what might port wine stain be associated with
Sturge-Weber syndrome
histopathology of BCC
clusters of darkly staining basaloid cells with peripheral palisading arrangement of nuclei
features of BCC
centrally ulcerated pearly edged papules with telangiectasia
most and least common location of BCC in the eyelid
most = lower lid least = lateral canthus
management of BCC
Mohs micrographic surgical excision (layered excision)
3 features of SCC
keratotic, ill-defined, may ulcerate
features of keratoacanthoma (type of SCC)
dome-shaped nodule with keratin-filled crater
2 treatments for SCC
Mohs surgery
radiotherapy
where does sebaceous gland carcinoma arise from
meibomian glands
glands of Zeis (less commony)
histopathology of sebaceous gland carcinoma
foamu vacuolated lipid-containing cytoplasm with hyperchromatic nuclei
what might sebaceous gland carcinoma be mistaken for
chalaazion - appear as a yellow nodule on the upper eyelid
what is trichiasis
misdirected growth of eyelash follicles - grow towards cornea or sclera
2 most common causes of trichiasis
herpes zoster ophthalmicus
blepharitis
what is distichiasis
formation of a pesterior row of eyelashes
4 causes of distichiasis
congenital (AD inheritence)
chemical injury
Stevens-Johnson syndrome
ocular cicatricial pemphigoid
2 types of blepharitis
anterior
posterior
what is anterior blepharitis
inflammation of the skin around the base of the eyelashes - staphylococcal or seborrheic
what is posterior blepharitis
inflammation of meibomian gland around the eyelid margins due to gland dysfunction
what might posterior blepharitis be associated with
ocular rosacea
4 rish factors for blepharitis
dry eyes
seborrheic dermatitis
dermodex folliculorum (associated with ocular rosacea)
long-term contact lens wear
4 clinical features of blepharitis
bilateral and symmetric
dry/gritty
crusted
red
what is staphylococcal anterior blepharitis associated with
atopic dermatitis
2 signs of staphylococcal anterior blepharitis
lid hyperaemia and swelling
hard scales and crusting of the bases of the lashes
3 things that might develop from staphylococcal anterior blepharitis
tear film instability
dry eye syndrome
trichiasis
what is seborrhoeic anterior blepharitis associated with
seborrheic dermatitis
2 signs of seborrhoeic anterior blepharitis
soft scales
oily lid margins
what is posterior blepharitis associated with
acne rosacea
3 signs of posterior blepharitis
foamy and unstable tear film
posterior lid margin hyperaemia and telangiectasia
3 forms of treatment for blepharitis
eyelid hygiene
antibiotics
tea tree oil for demodex infestation
type of antibiotics for blepharitis
tetracyclines (inability to inhibit fatty acid oxidation and lipase production)
4 types of causes of ptosis
neurogenic (Horners syndrome, CNIII palsy)
myogenic (myasthenia gravis, myotonic dystrophy)
involutional (age-related)
congenital (levator muscle)
what is Marcus Gunn jaw-winking syndrome
in 5% of patients with congenital ptosis - ptotic lid that retracts when the ipsilateral pterygoid muscle is stimulated
4 things that pseudoptosis includes
dermatochalasis
blepharochalasis
microphthalmus
phthisis bulbi (atrophic, non-functioning eye that occurs as a result of severe ocular disease)
what is dermatochalasis
excessive skin of upper eyelid = sagging (lateral hooding) - in elderly
what is blepharochalsis
bilateral, from abnormal elastic eyelids = recurrent episodes of painless oedema of upper eyelids
leads to stretching and atrophy of skin = skin folds and ptosis
what is floppy eyelid syndrome
in middle aged men with obstructive sleep apnoea - upper eyelid lax which may lead to papillary conjunctivtis and keratopathy
7 causes of lid retrction
graves ophthalmopathy parinaud syndrome (collier sign) third nerve misdirection marcuss gunn jaw-winking syndrome progressive supranuclear palsy down syndrome congenital hydrocephalus (bilteral downward devciation of the globes with upper lid retraction)
what is lid coloboma
incomplete development of the eyelid due to failure of lid fold fusion, either upper or lower lid
where does lid coloboma on the upper lid form and what is it associated with
forms at the junction of the middle and inner thirds of the upper eyelid
Goldenhar syndrome
what is goldenhar syndrome characterized by (5 things)
upper lid coloboma microphthalmia optic disc coloboma maxillary and mandibular hypoplasia limbal dermoids
what are limbal dermoids
smooth yellow subconjunctival mass typically at inferotemporal limbus with hair protrusion
what may limbal dermoids be associated with
Duane retraction syndrome
where does lid coloboma on the lower lid form and what is it associated with
forms at the junction of middle and outer thirds of lower eyelid
Treacher collins syndrome
what is a hordeolum
stye - external or internal
causes of external vs internal hordeolum
external = infection of glands of Zeis/Moll
internal = infection of meibomian gland
usually staph
3 treatments for stye
hot compresses
topical antibiotics
eyelid hygiene
