2.3 Ocular adnexa 1
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2.3 Ocular adnexa 1
What are the ocular adnexa? (6)
muscles of the eyelids and adjacent facial muscles
orbit and contents - EOM, orbital fat, nerves, vessels
innervation and vascular supply
Orbicularis oculi is divided into 3 parts. What are they?
What is the role of the orbital part of the OO?
What is the role of the palpebral part of the OO?
soft closure e.g. sleeping, blinking
What muscle and nerve is involved in lid closure?
What muscles and nerves are involved in lid opening?
levator - CN3
Muller's muscle - sympathetic innervaion
What are the branches of the LPS and what do they give rise to?
levator palpebrae superioris
superior - anterior and posterior layers of aponeurosis
inferior - muller's muscle
The bulbar conjunctiva merges with the __________ at the ___________
The palpebral/tarsal conjunctiva adheres tightly to the ________ and ________ to the inferior lid
tarsus of the superior lid
Normally there are more lashes in the:
a. upper lid
b. lower lid
a. upper lid
What are the fornices and what do they contain?
loosely attached conj
accessory lacrimal glands of Kraus (and Wolfring)
high conc of goblet cwwla, lymphocytes (CALT)
Where are eyelashes located?
At the anterior tarsal surface between orbicularis oculi and muscle of Riolan
Where do the lashes exit?
At the anterior lid margin and curves away from the globe
What eyelid glands are there?
Meibomian, Zeis, Moll, Krause, Wolfring
What are meibomian glands?
Modified sebaceous glands
What are Zeis glands?
Modified sebaceous glands at base of eyelash follicle
What are Moll glands?
Modified sweat glands
What are Krause and Wolfring glands?
Accessory lacrimal glands
What is trichiasis?
Abnormal misdirected growth of lashes
What is the cause of trichiasis?
Trichiasis is commonly acquired
Trichiasis is often secondary to? (4)
tarsal plate or conj scarring (e.g. trachoma, Stevens-Johnson syndrome
ageing changes (entropion)
How is pain from trichiasis relieved?
Pull the lid away from the eye
Signs and symptoms of trichiasis (8)
posterior misdirection of normal lashes
most frequently lower lid
corneal epithelial defects
Complications associated with trichiasis? (3)
worse with blinking
Worst case scenario associated with trichiasis? (3)
pannus (if long term)
Management of trichiasis? (3)
treat underlying cause
remove aberrant eyelashes
How can aberrant eyelashes be removed? (5)
What is trachoma?
A bacterial infection
Epidemiology of trachoma (5)
~84mil ppl in 51 endemic countries have active trachoma
WHO estimates ~6mil cases of blindness due to trachoma occur yearly
3% of global blindness
7 previously endemic countries (Gambia, Ghana, Iran, Morocco, Myanmar, Oman and Vietnam)
elimination of blinding trachoma as a public health problem
Cause of trachoma (2)
: Chlamydia trachomatis
a gram negative bacteria
Serotypes of C. Trachomatis
Serotypes A, B, Ba, C
: classic trachoma (poor hygeine)
Serotypes D to K
: adult inclusion conjunctivitis (sexually transmitted), neonatal conjunctivitis (Chlamydia most common infectious cause)
Serotypes L1 to L3
: lymphogranuloma venerem (a STD)
What are the two phases of trachoma
Signs during active phase of trachoma (5)
usually seen in children
conj inflammation (follicles and papillae)
irritating and watery discharge
Signs during cicatrical phase of trachoma (4)
tarsal conj scarring(esp upper) - linear/stellate then confluent
distortion of eyelid and trichiasis
secondary trichiasis/entropion and associated corneal scarring leading to blindness
resolved limbal follicles result in gaps in corneal pannus (Herbit's Pits)
Trachoma Grading Scale
: Trachamatous inflammation - follicular
: Trachomatous inflammation - intense
: Trachomatous scarring
: Trachomatous trachiasis
: Corneal opacity
What is distichiasis? (3)
extra row of lashes arising from meibomian gland orifices
associated with trichiasis
Causes of congenital distihiasis
differentiation of complete pilosebaceous glands (hair follicles) cf normal sebaceous (meibomian glands)
meibomian glands may be abnormal
Cause of acquired distichiasis (metaplastic lashes)
transformation from normal meibomian glands to hair follicles (pilosebaceous units)
related to conjunctival scarring
e.g. chemical burns, ocular pemphigoid, Stevens-Johnsons Syndrome
Treatment for distichiasis (3)
division into anterior and posterior lamellae
cryotherapy to posterior lamella
reapposition of lamellae
What is madarosis
Loss of eyelashes/eyebrows partial or complete
Cause of madarosis (6)