Eyelid + Eyebrow Flashcards
The position of the eyebrow is dependent on the relationship between
The elevator and depressor muscles (tone & innervation of muscle)
Associated glands in anterior lamella
Zeis and moll
Associated glands in posterior lamella
Meibomian
Meibomian glands of the posterior lamella maybe develop an abnormality of keratonization
Can result in inflammation leading to hordeolum or chalazion
Glands of zeis are
Sebaceous
Glands of moll
Sweat glands
Accessory row of eyelashes either partially or complete, emerges adjacent to or from opening of meibomian glands
Distichiasis
Can rub sclera
Acquired distichiasis usually occurs from
Chronic inflammation
Distichiasis is a _____ disease and many times the palpebral conjunctiva may be reflected and adhere to the bulbar conjunctiva
Mucocatenous
Look at mouth to see if it is systemic
Diseases that may lead to distichiasis are
Ocular cicatricial pemphigoid (fibrotic and becomes a scar)
Steven-Johnson syndrome
Normal eyelashes develop and have abnormal orientation, they grow in instead of out
Trichiasis
Principal functions of the eyelids
Protect (cilia and sensitive and have blink reflex )
Lubricate (gland)
Maintain integrity and clarity( smooth tears and cornea prevent opacities)
Entropion can be caused by
Alteration of muscle tone caused by pathology or innervation issue
Irritation in ectropion is caused by
Exposed area allows for evaporation and dehydration causing irritation
Spastic entropion
Overactive septal potion of o.o. Causes override of tarsal portion
(Neuro, inflam, irritation)
A tonic ectropion lower lid is due to
Loss of o.o. Tonus (nerve/palsy/muscle tone)
Paralytic ectropion
Flaccid paresis VII nerve (neuropathology or innervation issue)
Loss of eyebrows eyelids
Madarosis
Madarosis can occur in
Dermatological disorders and complex systemic diseases (mucatenous disorder)
Contraction of ____ helps in lacrimal pump mechanism
Pretarsal orbicularis muscle
Opening of eyelid
Muscle and innervation
LPS - CNIII
Sympathetic smooth muscle (muller)
Inferior + superior
Closing of eyelid
Muscle and nerve
Orbicularis oculi
CNVII
Sometimes the levator aponeurosis disinserts from its tarsal insertion with age resulting in
Ptosis (eyelid creases appears higher)
Muller muscle is____ and innervated by ____.
Minor retractor of the upper eyelid (opening)
Innervated by the sympathetic nervous system
In horners ____ pathway is affected
Sympathetic
Horners triad
Ptosis
Miosis
Anhidrosis
(Heterochromia in congenital only)
Ptosis in horners syndrome is caused by
Denervation of muller muscle
What is reverse ptosis
Lower lid elevation
Other names for horners
Claude Bernard/ oculosympathetic palsy
Quantify strength of levator by measuring displacement of the upper eyelid from down- upgaze
Normal 14-17mm
<4mm is poor
Sherrington law
Reciprocal innervation
Hearings law
Synergistic muscles receive simultaneous innervation (LPS)
Eyelid closing muscle and innervation
O.o. Innervated by VII
Eyelid closing also contributes to
Lacrimal pump mechanism
Blink reflex
Unforced/ forced eyelid closure
What part of the orbicularis is responsible for the blink reflex and unforced eyelid closure
Pretarsal and preseptal
Forced closure
Orbital part of o.o.
Part of o.o. in charge of lacrimal pump
Deep and superficial heads of the pretarsal o.o.
Benign essential blepharospasm
Orbital o.o.
Voluntary blink uses what part of o.o.
Palpebral and orbital
Rapid movement of muscle tissue requires
Low Chronaxie
Measure of electrophysiological irritability
Chronaxie ( how much time to excite muscle)
Chronaxie of palpebral o.o. =
1/2 Chronaxie orbital o.o.
Resting lid position depend on resting tonus of
LPS ands mueller muscle
Resting lid position can vary w state of arousdal
Serum level of catecholamines/ sympathetics
Bells phenomenon
Upward & outward rotation of globe with forced closure, sleep disappears in brainstem lesion above the pons
Myasthenia gravis
Ptosis
Graves
Exophthalmos/ proptosis
Blepharoptosis is drooping of upper eyelid due to
Paralysis of CNIII or sympathetic nerve
Or excessive weight of eyelids
Simple congenital ptosis
Dystrophy of the levator muscle
Aponeurotic congenital ptosis
Failure of aponeurosis to insert on tarsus
Congenital Synkinetic ptosis innervation and syndrome associated to it
Innervation of LPS by V3
Marcus Gunn jaw winking syndrome
Acquired aponeurotic ptosis
Abnormality on levator aponeurosis
CL wear, after ocular surgery, after trauma
Acquired neurogenic ptosis can be caused by
Horners or CNIII palsy
Acquired ptosis in dermatochalasis
Myopathy, neuromuscular, traumatic, brow ptosis
A bilateral, involuntary intermittent or persistent spasm of closure of eyelid w arrive contraction of muscles
Blepharospasm
O.o., procerus, corrugator