Term
| Is the palpebral or orbital orbicularis more excitable? |
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Definition
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Term
| What part of the orbicularis is involved in rapid blinks, reflex, spontaneous blinks and basic blinks? |
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Definition
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Term
| What part of the orbicularis is involved in forced closure blinks? |
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Definition
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Term
| The levator palpebrae superioris elevates what part of the lid? |
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Definition
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Term
| Are the right and left levator palpebrae superioris yoked? |
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Definition
| Yes - they receive equal innervation |
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Term
| What muscle is responsible for the tonic lid position? |
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Definition
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Term
| The superior tarsal muscle of Meuller runs from the levator palpebrae superioris connective tissue sheath, under the levator palpebrae superioris itself, and finally to where? |
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Definition
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Term
| The inferior tarsal muscle or Mueller runs from where to the inferior tarsal plate? |
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Definition
| IR/IO connective tissue sheath |
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Term
| What is the only muscle that depresses the lower lid? |
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Definition
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Term
| The Meuller muscle receives what type of nervous system innervation? |
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Definition
| Sympathetic Nervous system |
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Term
| What is Bell's phenomenon? |
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Definition
| It is the upward and outward rotation of the globe that happens with forced closure and sleeping. It is a normal protective response |
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Term
| The Bell's phenomenon signals an intact what in an unconscious patient? |
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Definition
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Term
| When will Bell's phenomenon disappear? |
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Definition
| If you have a brainstem lesion above the pons |
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Term
| Are Bell's phenomenon and Bell's Palsy the same thing? |
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Definition
| NO - Bell's palsy involves twitching, weakness, or paralysis of the face due to irritation of the facial nerve (CN 7) |
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Term
| How does the lid receive its sensory innervation? |
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Definition
| Through the ophthalmic branch (V1) of the Trigeminal nerve (CN 5) |
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Term
| The sensory plexus for the lid is deep to the palpebral fibers of the orbicularis oculi so it requires what for anestheses? |
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Definition
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Term
| Is a hordeolum or a chalazion painful? |
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Definition
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Term
| What is preseptal cellulitis? |
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Definition
| An infection of the preseptal region of the eyelid. It can start as a hordeolum |
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Term
| What is the eyelid disorder that is marked by cholesterol deposits on the upper medial eyelid margin? |
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Definition
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Term
| In spastic entropion this portion of the orbicularis oculi is overeactive and causes override of the tarsal portion. |
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Definition
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Term
| What is atonic ectropion of the lower lid? |
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Definition
| It is a loss of orbicularis oculi tonus |
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Term
| Paralytic ectropion of the lower lid is caused by what? |
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Definition
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Term
| Ankyloblepharon is characterized by what? |
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Definition
| Adhesions of the upper and lower lid |
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Term
| What is blepharophimosis? |
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Definition
Inverted epicanthal folds
Leads to reduced fissure |
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Term
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Definition
It is where there is no lid opening at all - lids are fused
Ankyloblepharon totale |
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Term
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Definition
| Failed closure of the fetal fissure |
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Term
| What is blepharochalasis? |
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Definition
| It is a loss of orbital septum allowing a fat prolapse - saggy lids |
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Term
| Are the elderly the only people to get blepharochalasis? |
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Definition
| NO - Young people can get the condition following chronic edema |
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Term
| Is blepharochalasis a ptosis? |
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Definition
| NO - The input and tonus of the levator is normal but the tissues are drooping. It is a Psuedotosis |
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Term
| What can cause a blepharospasm? What does it look like? |
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Definition
An irritated CN 7 can cause it.
The eyelids will not unclamp |
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Term
| What is a myokymia? What causes it? |
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Definition
It is an eyelid twitch.
It can be caused by stress, lack of sleep, or idiopathic reasons |
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Term
| In Bell's palsy, are emotional or voluntary actions affected? |
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Definition
Not as affected
It is mainly your voluntary actions that are affected |
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Term
| What are some symptoms of Bell's palsy? Is it usually bilateral or unilateral? What percentage usually recovers? |
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Definition
Lagophthalmos and widened palpebral fissure, facial twitching, etc
Usually unilateral
86% recover completley |
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Term
| The restinf lid position depends upon the resting tonus of what two muscles? |
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Definition
| The levator palpebrae superioris and Mueller's muscle |
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Term
| The resting lid position can vary with what state? |
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Definition
| Your arousal state (serum level of catecholamines) |
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Term
| If there is asymmetry between your two vertical palpebral fissures is this a problem? |
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Definition
| YES - It has pathological significance |
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Term
| In congenital ptosis, with downgaze the normal lid moves where? |
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Definition
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Term
| What causes a Psuedo-Grafe? |
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Definition
| Abberant regeneration of CN 3 |
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Term
| What are some signs and symptoms of a Pseuo-Grafe? |
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Definition
It is a mix-up of what should normally happen with the eyelids.
Ptosis, lid elevation with downgaze or adduction. You may have a pupil that is non-reactive to light but that constricts with adduction. |
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Term
| In Marcus-Gunn Phenomenon what happens because of bad wiring between the brain, jaw and lid? |
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Definition
| “Jaw winking” – lid retraction with mouth open or lateral jaw movement |
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Term
| What is Collier’s sign? Signs and symptoms? |
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Definition
Symmetric upper lid retraction – 2nd most common cause of lid retraction
Characteristic stare (staring all the time) and commonly upgaze paresis |
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Term
| What causes Collier’s sign? |
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Definition
| Pretectal/dorsal midbrain lesion |
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Term
| What is the most common cause of lid retraction? |
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Definition
| Hyperthyroidism – Grave’s Disease |
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Term
| What is Dalrymple’s Sign? |
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Definition
| Widening of the palpebral fissure due to excessive tonus of Muller muscle or excessive tonus of the levator palpebrae |
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Term
| Widening of the palpebral fissure due to retraction of the upper eyelids is responsible for the apparent exophthalmos seen in what? |
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Definition
| Thyrotoxicosis – Complication associated with Grave’s disease |
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Term
| The principal reason for the prominent appearance of the eye is what? |
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Definition
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Term
| With Von Graefe’s Sign, the patient manifests a “lid-lag” because of a mismatch of signals between the globe and lid. In downgaze, what can be seen in these patients? |
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Definition
| Inability of the upper lid to follow the movements of the globe |
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Term
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Definition
| Bilateral, involuntary intermittent or persistent spasmodic closure of the eyelids with active contraction of the orbicularis oculi and the procerus and corrugator muscles. |
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Term
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Definition
| Drooping of the upper eyelid due to paralysis of the occulomotor nerve (CN3) or sympathetic nerve or by excessive weight of the upper eyelids |
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Term
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Definition
| Exaggerated reflex blinking |
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Term
| What is blepharophimosis? |
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Definition
| Decreased size of the palpebral fissure, often due to increased distance between the inner canthui (telecanthus) or drooping upper eyelid (blepharoptosis) |
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Term
| The eyelids close in a zipper fashion. What moves where? |
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Definition
| Upper eyelid moves down and nasal, the lower lid moves nasally (depressed momentarily when contracted by upper lid), the lateral canthus moves nasally and the medial canthus stays stationary |
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Term
| Of the three types of blinking, spontaneous, reflex, and voluntary, which is the most common yet the mechanism is the least understood? |
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Definition
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Term
| Reflex blinking can be elicited by what kind of stimulation? |
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Definition
| Sensory – touch, auditory, light, irritation |
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Term
| Voluntary blinking is accomplished by what two parts of the orbicularis oculi? |
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Definition
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Term
| Spontaneous (basic) blinking is elicited by what muscle? |
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Definition
| Palpebral orbicularis oculi |
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Term
| Are basic blinks (spontaneous) 100% complete? |
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Definition
| NO – 75% complete under ideal conditions. They can be even less complete when attending to something or doing activities (ie computer). |
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Term
| How many spontaneous blinks does an adult average per minute? Newborn? |
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Definition
Adult – 12-15x/min
Newborn – less than 3x/min |
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Term
| Although the reflex stimulus that initiates a spontaneous blink is largely unknown, what do some believe it is do to? |
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Definition
| The tear film becomes hypertonic with increased exposure to the air. This is then detected by nerve endings (eyelid? eye?) which then stimulate the lid to come down |
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Term
| Can your number of basic blinks vary? |
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Definition
| YES – Can vary with stimuli, conditions, or emotion |
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Term
| Blinking data shows that you can _______ your eye twice as fast as you can ______ it. |
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Definition
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Term
| In a protective tactile reflex blink, what are the afferent and efferent pathways? |
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Definition
Afferent – CN5 to Gasserian ganglion to midbrain
Efferent – CN 7 nucleus to orbicularis oculi |
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Term
| Does a tactile reflex blink require cortical input? Can it be reduced with CL wear? |
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Definition
YES – absence most commonly due to CN 5 damage
YES |
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Term
| How do you quantify a tactile reflex blink? |
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Definition
| An aesthesiometer or cotton wisp |
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Term
| You receive a visual reflex that suprises you or dazzles you. What are the afferent and efferent pathways? Is it cortically dependent? |
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Definition
Afferent – CN 2 to superior colliculus and supraoptic nuclei
Efferent – CN 7 nucleus to orbicularis oculi
It is not cortically dependent – it is entirely brainstem mediated |
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Term
| How can this dazzle reflex blink be lost? |
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Definition
| With a mesencephalic lesion |
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Term
| You receive a visual reflex that appears to be menacing. What are the afferent and efferent pathways? Is it cortically dependant? Is it a learned reflex? |
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Definition
Afferent – CN 2 to LGN to primary visual cortex and associated fibers to Rolandic area
Efferent – CN 7 nucleus to orbicularis oculi
It is cortically dependent – requires input from occipital lobe and parietal and frontal lobes mediate your visual attention
It may be a learned reflex (after age 2-4 months) |
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Term
| A book drops on the floor unexpectedly and elicits a auditory (stapedius) reflex blink. What are the afferent and efferent pathways? |
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Definition
Afferent – CN 8 to auditory nucleus
Efferent – CN 7 nucleus to orbicularis oculi |
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Term
| The cortical control of an elevating lid movement occurs where? |
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Definition
| Frontal cortex (oculogyric center) |
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Term
| The cortical control of a closure lid movement occurs where? |
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Definition
| Motor cortex (precentral gyrus) |
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Term
| The eyelids move with similar speed and conjugacy to what EOM’s? |
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Definition
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Term
| In downgaze, the upper lid depresses due to the relaxation of what muscle and the tonus of what other muscle? This is an example of what law? |
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Definition
Relaxation of the levator palpebrae superioris and tonus of orbicularis oculi
Sherrington’s Law |
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Term
| The upper eyelid elevates with upgaze synergistically with what muscle? Why does this occur? |
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Definition
| Superior rectus; they share a common facial sheath |
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Term
| Is there an association of ptosis and superior rectus palsy? |
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Definition
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Term
| Both levator palpebrae superiori are under the control of what nucleus of CN3? |
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Definition
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Term
| In the midbrain, what nucleus inhibits the central caudate nucleus? |
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Definition
Nucleus of posterior commisure
Example – In downgaze the nucleus of posterior commisure fires and inhibits the central caudate nucleus allowing eyelid relaxation |
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