Eyelids Flashcards
What is Blepharochalasis?
Orbital fat herniation into the eyelid that causes droopiness and puffiness of the eye.
What structure of the eyelid is very thin, elastic and fat free?
Skin.
True or False: Benign growths are evenly distributed between upper and lower lids.
True.
Malignant tumors are four times more common in which lid? Why?
Lower lid. Upper eyelid has eyebrows to protect the eyelid from sun.
What is the action of the levator palpebrae superioris muscle?
To elevate the upper lid.
What is the action of the orbicularis oculi muscle?
Closes the lids, helps hold the lid tightly against the eye, which assists in spreading tears and flushing away waste products.
What is the action of Mueller muscle fibers?
To modulate position of lids of the open eye and to keep it open.
A fold of skin separating the palpebral from the orbital potion of the lid marks insertion of what muscle?
Levator.
Absence of the fold is seen during what condition?
Ptosis.
Orbicularis oculi is what type of muscle?
Striated and voluntary.
Which cranial nerve is orbicularis oculi innervated by?
CN VII (facial).
Paralysis of CN VII for the orbicularis oculi results in what?
Dry eye condition, lagophthalmus, due to an inability to close the eyelids.
Levator palpebrae superioris is what type of muscle? Which lid is it found in?
Striated; Only upper eyelid.
Once the levator palpebrae superioris becomes tendinous as it enters the lid, it is now known as what?
Aponeurosis of the levator.
Which cranial nerve is the levator palpebrae superioris innervated by?
Superior division of oculomotor CN III.
The tarsal muscle (both superior and inferior position aka Mueller) is innervated by the parasympathetics or sympathetics?
Sympathetics.
Damage to the sympathetics causes what?
Droopy eyes.
What is submuscular areolar tissue and where is it found?
Loose connective tissue between muscle and tarsal plate. It’s fat free.
Dense fibrous tissue that gives firmness and shape to eyelids is known as what?
Tarsal plate.
What allows the upper eyelid to be everted?
Collagen being more developed in the upper lid.
What is Floppy Eyelid Syndrome?
Upper eyelids flaccid and easily everted. Tarsal plate loses its elasticity.
What are symptoms of Floppy Eyelid Syndrome?
Burning and irritation of eyes, contact between eye and pillow during sleep, inadequate spreading of tear film, meibomian gland dysfunction.
Floppy Eyelid Syndrome is often associated with what?
Sleep apnea.
How many eyelashes are in the upper and lower eyelid?
100-150 upper cilia and 50-75 lower cilia.
How long do eyelashes last?
2-5 months.
How long does it take for forcibly removed eyelashes to grow back?
2 months.
Chief secretion of the eyelid is what? What part of the eyelid secretes this?
Sebum, oily material secreted by meibomian glands.
What is the purpose of the oily layer in the tear film?
Slows evaporation of the aqueous component and allows for hydrophobic barrier to prevent tear spillage.
What is in the tear film from deep to superficial?
Mucous, Aqueous, Oil.
What are meibomian glands?
Tarsal glands, modified sebaceous glands located within the lid margin that secrete sebum, or oily layer of the tear film.
Blood supply of the eyelid is through what two systems?
Facial system (from external carotid artery) and orbital system (from internal carotid artery). Arteries in the lid anastomose (form two transverse arcades per eyelid).
Venous drainage of the eyelid is through what two systems?
Superficial (pre-tarsal) system and deep (post-tarsal) system.
Lymphatics of eyelids and conjunctiva is divided into what two systems?
Superficial or pre-tarsal plexus and deep or post-tarsal plexus.
Paralysis of CN VII causes what?
Causes eyebrow to be lower on affected side.
Weakness of CN III in the levator palpebrae superioris causes what?
Ptosis of the upper lid.
Paralysis of CN III in the levator palpebrae superioris causes what?
Complete closer of the upper lid.
Sympathetic paralysis of Mueller’s muscle causes what? This is one of the components of what syndrome?
Minor ptosis, droopy eyes. Horner’s syndrome.
What is one way of treating sympathetic paralysis of Mueller’s muscle to stop eye droopiness?
Weak solutions of epinephrine causes reversal of the ptosis secondary to sympathetic paralysis.
What is Horner’s syndrome?
Ptosis, miosis (constriction of pupil), anhydrosis (sweating decreased).
What is the action of the frontalis muscle?
Raises eyebrow.
How many portions does the orbicularis oculi have?
- Orbital, palpebral, ciliary, lacrimal.
What is the action of the corrugator supercilii muscle?
Pulls eyebrows together (frown).
What is Bell’s phenomenon?
The globe turns upward as the eyelids are forced closed.
What is reflex blinking?
Involuntary blinking of the eyelids elicited by stimulation of the cornea and tactics, optics, and auditory sensations like: touch, strong light, approaching objects, loud noise.
What quantifies as the corneal reflex?
Aesthesiometer.
When does the tactile corneal reflex become diminished slightly?
In contact lens users.
A natural, high-speed response to tactile and proprioceptive stimuli is what?
Reflex Blink.
A slow, sustained closure to nociceptive (pain) stimuli is what? (twitch, involuntary closure of eyelid).
Blepharospasm.
When does spontaneous blinking occur?
On a regular basis without external stimulus.
Computer users, or any activity that involves increased attention causes blink rate to what?
Decrease.
Is the blinking rate or infants high or low?
Low.
During blinking, most of the movement is caused by which eyelid?
Upper. Lower remains relatively stationary.
During each blink, how does the palpebral fissure narrow?
A zipper-like motion laterally to medially.
Where does the tears move into?
Puncta.
What is the spontaneous blink rate?
15 blinks per minute.
What is the duration of each blink?
300-400 msec.
What is the average time between blinks?
2.8 seconds.
What is voluntary winking?
Consciously initiated closure of one eye.
Most people can freely wink in which eye?
Left, due to the predominance of right-handedness.
What is blepharospasm?
An idiopathic disorder of neuromuscular control of orbicularis oculi that results in simultaneous bilateral, symmetrical, progressive, involuntary closure of both eyes.
Does blepharospasm raise or lower IOP? How is this relieved?
Rasies; botulinum-A toxin (botox).
What is myokymia? Is it related to the severe dystonias? How is it caused?
Fibrillary twitching of the eyelids; no; caused due to fatigue, thyrotoxicosis, and stress.
Incomplete closure of the eyes during sleep resulting in desiccation and excessive exposure of the lower portions of the cornea is called what?
Lagophthalmos.
A falling away of the lower eyelid away from the globe is called what?
Ectopion.
What causes ectopion and what does this result in?
Weakness of orbicularis muscle; results in epiphoria (overflow of tears down face) and poor blink closure.
A turning in of the eyelid is known as what?
Entropion.
What is a result of entropion?
Trichiasis.
How wide is the palpebral fissure vertically and horizontally?
8-11 mm vertically 27-30 horizontally.
Forward displacement of the eye causes the palpebral to what?
Widen.
Exophthalmos is seen in what type of disease?
Thyroid Disease.
True or False: Retraction of the upper eyelids causes a widening of the palpebral fissure.
True.
Collier’s sign is?
Retraction of the upper lid(s).
Delay of movement of the upper lid when shifting gaze from up to down and causes a staring expression is known as what?
Von Grafe’s Sign.
