Eyelids Flashcards
What are the ocular movements associated with palpebral closure?
- temporal angle moves nasally and downward
- upper lid moves down and medially
- lower lid moves mostly medially
What is the innervation (1) and the action (2) of the orbicularis oculi muscle?
- Cranial Nerve VII
2. depress eyebrow and forehead
What is the innervation (1) and the action (2) of the Horner’s muscle?
- CN VII
2. Compresses canaliculi
What is the innervation (1) and the action (2) of the Riolan’s muscle?
- CN VII
2. Holds lid margin in close contact with globe
What is the innervation (1) and the action (2) of the Levator palpebrae superioris (LPS) muscle?
- CN III
2. Elevates eyelid
What is the innervation (1) and the action (2) of the tarsal muscles?
- sympathetic
2. Additional lid elevation
What is the function of the eyebrows?
- Communication
- Identification
- Shield eyes from light
- Prevent fluids from running into eyes
- Protection of the eye
- Participation in ocular movements
What is the innervation (1) and the action (2) of the frontalis muscle?
- CN VII
2. raise eyebrow (look of surprise)
What is the innervation (1) and the action (2) of the procerus muscle?
- CN VII
2. inferior movement of medial brow (look of menace)
What is the innervation (1) and the action (2) of the depressor supercilii muscle?
- CN VII
2. depresses eyebrow
What is the innervation (1) and the action (2) of the corrugator supercilii muscle?
- CN VII
2. draws eyebrows medially (look of concentration)
What are the function(s) of the palpebrae?
- Globe protection
- Produce tear film components
- Spread tear film
- Assist in tear drainage
What type of eyelid closure is palpebral?
rapid response, blinking
What type of eyelid closure is orbital?
sustained or forceful closure
What is the relationship between blink velocity and blink amplitude?
Linear relationship
If there are large increases in blink amplitude how is blink duration affected?
blink duration changes little
What are the three types of blinking?
- spontaneous
- voluntary
- reflexive
How long does it take to blink?
257.9 msec
What things increase blinking rate?
- contact lens use
- speaking
- emotional states (anger, excitement)
What things decrease blinking rate?
- age
- sustained visual tracking
- daydreaming
- downward gaze
Which blinking pattern is described by no obvious modal value in the range of interblink interval (IEBI) measurements?
I-type (Irregular)
Which blinking pattern is described by most IEBI values being short interspersed by few longer IEBI (skewed distribution)?
J-type
Which blinking pattern is described by IEBI values grouped around two modes?
Bimodal
Which blinking pattern is described by a Gaussian distribution with a clear modal value?
Symmetrical
What are the ocular movements that occur as a consequence of a blink?
- Posterior movement of globe
2. in primary gaze, eye rotates downward and nasally
What are the ocular movements that occur as a consequence of a forceful closure (and what is this motion called)?
Upward/Outward rotation of eyes (Bell’s Phenomenon)
What modify gaze shifts and shorten latency between saccades?
blinks
What are vertical movements of upper eyelid that accompany voluntary vertical movements of the eyes?
lid saccades
What type of saccade increases LPS activity? 1. What type decreases it? 2
- upward saccade
2. downward saccade
Does dopamine increase of decrease spontaneous blink rate?
increase
What spontaneous movement abnormality is associated with persistence of OO activity following voluntary closure of eyelids, inability to open lids, reduction in OO and increase in LPS, and poor reciprocal inhibition?
Blepharospasm
What spontaneous movement abnormality is associated with a large amplitude, involuntary tremors of the orbicularis oculi muscles, observed during gentle closure of the eyelids and may follow head trauma?
Blepharoclonus
What spontaneous movement abnormality is associated with involuntary eyelid muscle contraction, typically involving the lower eyelid?
myokymia
What is a treatment for blepharospasm and its mechanism?
botulinum toxin (botox) by cleaving SNARE proteins
What are the afferent fibers (1), efferent fibers (2) and central connection (3) associated with tactile reflex blinking?
- CN V
- CN VII
- cortical
What are the afferent fibers (1), efferent fibers (2) and central connection (3) associated with dazzle reflex blinking?
- CN II
- CN VII
- subcortical
What are the afferent fibers (1), efferent fibers (2) and central connection (3) associated with menace reflex blinking?
- CN II
- CN VII
- cortical
What are the afferent fibers (1), efferent fibers (2) and central connection (3) associated with auditory reflex blinking?
- CN VIII
- CN VII
- subcortical
Which lid pathology includes acute unilateral facial weakness, impaired ability to close eyes, loss of normal facial creases and folds, widening of palpebral aperture, and laxity of lower lid?
Bell’s Palsy
What are the two theories of cause for Bell’s Palsy?
- compression theory (narrow facial canal)
2. immune-inflammatory theory (demyelination with inflammation)
What is the autoimmune disorder that causes over-production of TSH receptor antibodies and causes eyelid problems, exophthalmos, and EOM issues?
Grave’s Disease
What is the eyelid sign in Grave’s Disease that is a retraction of the upper lid?
Dalrymple’s Sign
What is the eyelid sign in Grave’s Disease that is a upper lid lag on downward gaze?
Von Graefe’s Sign
What is a the widening of the palpebral fissure due to an increase in the tonus in the levator palpebrae superioris as a result of diseases affecting the pretectal region of the brain, particularly the posterior commissure called?
Collier’s Sign
What lid retraction abnormality is associated with following recovery from CN III paralysis, misdirection of fibers intended for the medial rectus to the levator, excessive widening in adduction, and ptosis in abduction?
Pseudo-Graefe Phenomenon
What is a redundant fold of skin in medial canthus called?
epicanthus
What condition is associated with inability to look upwards, downwards, medially; eye down and out; diplopia; ptosis; dilated nonreactive pupils; and lack of accommodation?
Oculomotor nerve palsy
What condition is associated with the possibility of being due to a failure of extraocular muscle development and/or innervation, or due to misrouting of neurons during development, and can cause ambylopia?
congenital ptosis
What condition is associated with ptosis relieved when jaw is moved away from affected eye, opening and shutting of eye on chewing, and pterygoid muscle linked to levator at cortical level?
Marcus Gunn Jaw Winking Phenomenon
What condition is associated with sympathetic denervation resulting in ptosis, miosis (pupil constriction), and facial anhidrosis?
Horner’s syndrome
What condition is caused by a disruption of the levator aponeurosis insertion?
Aponeurotic ptosis
What condition is associated with mechanical ptosis due to neurofibroma?
mechanical ptosis
