EYELIDS

Question 1

What are the structures of the eyelid?

Answer 1

skin, muscle, fibrous layer, palpebral conjunctiva, subcutaneous layer, submuscular areolar layer

Question 2

what are the portions of the eyelid?

Answer 2

orbital portion, tarsal portion, lateral canthus, medial canthus, superior palpebral furrow, caruncle, inferior palpebral furrow

Question 3

what is blepharochalasis?

Answer 3

orbital fat herniation.

Question 4

what is significant about the skin (dermis) of the eyelid?

Answer 4

has no fat, unlike dermis in the rest of body. very thin and elastic, fat free.

Question 5

what is basal cell carcinoma related to?

Answer 5

UV light exposure

Question 6

what part of the eyelid is more prone to cancer?

Answer 6

the inferior lid. because the eyebrow protects the superior from the sun. four times more common in lower lid.

Question 7

how are benign growths distributed on lids?

Answer 7

evenly upper and lower lid.

Question 8

what are the muscles of the eyelid? what is their function

Answer 8

levator palpebral superioris = elevates lids. (innervated by CN III ocular motor nerve) (striated).
orbicularis occuli = close eyelid. (striated muscle). assist in spreading tears and flushing away waste products. voluntary muscle.
Mueller’s muscle fibers= assist levetor superioris in lifting lid. Modulate position of the open eyelid. expression of fear.

Question 9

absence of a fold is described as what clinically?

Answer 9

ptosis

Question 10

what marks the insertion of the levator papebral superioris?

Answer 10

fold of skin separating the palpebral from the orbital portion.

Question 11

what is the orbicularis occuli innervated by?

Answer 11

CN VII (facial)

Question 12

paralysis of orbicularis occuli innervated by CN VII leads to what condition?

Answer 12

dry eye condition and lagophthalmus

Question 13

what is lagophthalmus?

Answer 13

inability to close eye lids. incomplete closure of eyelid during sleep. exposure of cornea-scleral limbus. lower cornea is usually what gets dry.

Question 14

levator palpebral superioris becomes tendinous where?

Answer 14

aponeurosis of the levator.

Question 15

muller muscle (superior and inferior) or tarsal muscles is innervated by what?

Answer 15

sympathetic nervous system

Question 16

damage to sympathetic innervation can cause what?

Answer 16

droopy lid.

Question 17

what is the function of the fibrous layer tarsal plate?

Answer 17

dense fibrous tissue that gives firmness and shape to eye lids.

Question 18

what is the function of the submuscular areolar tissue?

Answer 18

loose connective tissue between muscle and tarsal plate.

Question 19

collagen is more developed in which part of the lid upper or lower? which is everted usually?

Answer 19

collagen is more developed in upper lid. Allows upper lid to be everted.

Question 20

what are characteristics of Floppy Eyelid Syndrome?

Answer 20

flaccid upper lid, genetic abnormalities in collagen or elastin of lid. decrease tarsal elastin.

Question 21

patients with Floppy eye syndrome will experience what symptoms?

Answer 21

irritation and burning of eye. Eyelid rub against pillow while sleeping. meibomian gland dysfunction, inadequate spreading of tears. and poor apposition of eyelid to globe. associated with sleep apnea. don’t confuse with floppy iris syndrome.

Question 22

how many lashes does the upper and lower lid have?

what is the lifespan? How long does it take to be replaced when forcibly removed?

Answer 22

upper= 100-150
lower= 50-75
The lifespan is about 3-5 months
It takes 2 months to be replaced when forcibly removed.

Question 23

explain eyelid secretion.

Answer 23

Chief secretion: sebum
Oily material secreted by the meibomian glands
The sebum forms a superficial layer over the precorneal tear film which slows evaporation of the aqueous component. A hydrophobic barrier is formed to prevent tear spillage.

Question 24

what is the function of the miebomian glands?

Answer 24

secrete oil layer of tear. sebum. forms surface of tear. large sebecaus glands embedded in tarsal plates. there are 30 glands in each tarsus. pressure in the glands cause the glands to excrete.

Question 25

what are the accessory lacrimal glands called?

Answer 25

wolfrig and krause

Question 26

what is the arterial supply of the eyelid?

Answer 26

Arteries in lid anastomose – form two transverse arcades per eyelid Arterial supply: Facial system (from external carotid artery) Orbital system (from internal carotid artery)

Question 27

what is the venous drainage of the eyelid?

Answer 27

superficial system (pre-tarsal) and deep system (post tarsal)

Question 28

describe lymphatics of the eye lid.

Answer 28

lymphatics are found in the eye lid and the conjunctiva. | divided into two parts superficial (pre-tarsal plexus) and Deep post-tarsal plexus)

Question 29

What happens with paralysis of CN 7?

Answer 29

the eyebrow is lower on the affected area side.

Question 30

what happens when CN 3 is affected?

Answer 30

Weak= ptosis paralysis= complete closure of the eye if lift the eyelid patient would see double.

Question 31

which EOM are supplied by CN3?

Answer 31

``` medial rectus, inferior rectus, superior rectus, inferior oblique. REMEMBER: all the rest CN3. and S04 LR 6 ```

Question 32

what muscle can try to compensate to lift lid for patient with ptosis?

Answer 32

the frontalis muscle, which lifts the eyebrow.

Question 33

what happens when there is a sympathetic paralysis of Muller's muscle?

Answer 33

a small ptosis can occur. sympathetic paralysis is a component of horner's syndrome. however, it can be treated with low weak dosage solution of epinephrine to fix it.

Question 34

what does the corrugator supercilli and frontalis muscle do?

Answer 34

pulls eyebrows together = frown | frontalis muscle= raises eyebrows

Question 35

what's bell's phenomenon?

Answer 35

The globe turns upward as the eyelids are forced closed. (protects cornea by moving it up). Try applying force on the orbicularis muscle and ask the patient to close eyelid.

Question 36

what's reflex blinking?

Answer 36

rapid closure movement and a response to stimuli. Examples: rapid object movement toward eye, touch, strong lights, loud noise, etc.

Question 37

what does a aesthesiometer do?

Answer 37

corneal reflex.

Question 38

in the contact lens wearer, what can happen to corneal reflex?

Answer 38

tactile corneal reflex is reduced.

Question 39

what is blepharospasm?

Answer 39

Muscle cannot relax. Raises IOP (intraocular pressure). Involuntary closure of eyes. Slow, sustained closure to nonreceptive (pain) stimuli. idiopathic disorder of neuromuscular control. (effects orbicularis oculi). Botox lasts 2-3 months or can be treated temporarily by butolinum (toxin).

Question 40

explain spontaneous blinking.

Answer 40

happens on a regular basis. Lower lid remains almost stationary most the movement is made by the upper lid The palpebral fissure narrows in a zipper-like motion laterally to medially. Tear strip moves towards the puncta rate is low or absent in infants. happens despite blindness.

Question 41

what is the spontaneous blink rate? Duration between blinks? how long is blink?

Answer 41

we blink 15 times per minute blink= 300-400 msec duration between blinks= 2.8 sections obscuring visual input for more than 30 msec is detectable but for less than 3 msec not detectable.

Question 42

what is voluntary winking?

Answer 42

voluntary closure of the eye. Most people can wink with left eye freely and not right. This is related to predominance of right handedness.

Question 43

what is myokima?

Answer 43

Eyelid twitching. Aggravated by fatigue, thyrotoxicosis, and psychological stress.

Question 44

what is ectropin?

Answer 44

excessive watery eye. falling away of lower lid from eye or globe. not good blinking. orbicularis occuli effected. senile ectropion is secondary loss of tone and fat deep around globe due to age..

Question 45

what is entropion?

Answer 45

A turning in of the eyelid. Cicatrical entropion with resulting trichiasis (contact bw eyelid and corneal surface). Characteristic with trachoma (Chlamydia infection) and ocular pemphigoid . causes cornea to become opaque.

Question 46

explain exophthalmus

Answer 46

found in thyroid disease. Retraction of the upper eyelids causes a widening of the palpebral fissure Thyroid eye disease: Exophthalmometry measurements are remarkably similar to normal patients Vertical fissure measurements are better. Measurements ranging from 12 to 21 mm are obtained in normal subjects with a mean of 16 mm, while those with thyroid eye disease yield values ranging from 12 to 24 mm with a mean of 18 mm. Measurements of greater than 19 mm however, were found in only about 5% of normals, while 32% of those with thyroid eye disease fell above this level. The principal component in the apparent exophthalmos of thyroid eye disease is the degree of lid retraction. Thus measurement of the vertical palpebral fissure width may be a more important measure than exophthalmometry.

Question 47

what is collier's sign?

Answer 47

retraction of upper eye lid. Type of Thyrotoxicosis. when one eye is more open or projected than the other expect thyroid disease.

Question 48

what is von grafe's sign?

Answer 48

delay of movement of the upper lids when shifting gaze up and down; causing a staring expression. A lid lag. Type of Thyrotoxicosis.