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Ocular Physio > Eyelids > Flashcards

Flashcards in Eyelids Deck (47):
1

Describe skin of eyelids?

fat free, thin, elastic

2

Describe benign and malignant growths in eyelids?

Both upper and lower eyelids have equal amounts of benign growths; malignant are more than 4x likely to develop in lower eyelid because the eyebrow protects upper lid from sun

3

Levator Palpebrae Superioris

elevates upper lid; striated muscle; becomes tendinous as it enters the lid; innervated by oculomotor nerve 3

4

Obicularis Oculi? Innervated by?

closes lids; striated voluntary muscle; helps in spreading tears and flushing away waste products; innervated by cranial nerve 7; paralysis leads to dry eye syndrome, lagopthalmus

5

Muller Muscle Fibers

modulate position of lids of the open eye; sympathetic innervation (damage leads to droopy eye); found in both lids; lines levator internally; contraction aids in action of levator; wide eyed expression of fear

6

Insertion of Levator Palpebrae Superioris

crease marked between the palpebral and orbital parts of eyelid

7

Lack of fold means?

Ptosis; levator did not enter correctly

8

Submuscular Areolar Tissue

loose connective tissue between muscle and tarsal plate; fat free

9

Fibrous Layer

dense fibrous tissue that gives shape and firmness; known as tarsal plate; collagen more developed in upper lid than lower (eversion)

10

Floppy Eyelid Syndrome

upper lid can be everted more than usual ; decreased tarsal elastin; genetic abnormalities of collagen or elastin
eyes burn and irritated, contact with eyelid and pillow ; poor apposition of eyelid to globe inadequate spreading of tear film; meibomian gland dysfunction

associated with sleep apnea

11

Cilia

upper= 100-150; lower 50-75; lifespan 3-5 months; forcibly removed will grown back in 2 months (leprocy, psych disorders)

12

What is chief secretion and what is it secreted by?

sebum; meibomian glands. forms superficial layer over precorneal tear film that slows evaporation of aqueous

13

Arterial Supply

Facial system; orbital system

14

Venous Drainage

superficial (pre) and deep (post)

15

Lymphatic System

deep and superficial

16

Damage of CN 7

causes brow to droop down on side affected

17

Paralysis of CN 3

Ptosis of upper eyelid; complete closure of lid; frontalis works harder

18

Paralysis of Sympathetic Nerve (Muller's Muscle)

causes minor ptosis; associated with Horner's syndrome; can be reversed by weak epinephrine (topical)

19

What are the muscles of the eyebrow?

Frontalis, Obicularis Oculi, Corrugator supercilli

20

Frontalis

Raises eyebrows; oriented radially over forehead

21

Obicularis Oculi

found in eyelid; has orbital, palpebral, and ciliary portions ; muscle fibers oriented concentrically; sphincter action closes eyelids

22

Corrugator supercili

pulls eyebrows together; frowning

23

Bell's phenomenom

Turns globe upward as lids are forcefully closed / does not occur with reflex blinking (cornea turns upward to avoid drying or becoming opaque)

24

Sensory modalities stimulated during reflex blinking (3)?

Tactile, optic, and auditory sensations; touch, Strong lights, Approaching objects, loud noise

25

Reflex blinking

Reflex blinking is a rapid closure movement of short duration

26

What quantifies corneal reflex?

Aesthesiometer

27

Corneal reflex diminished in?

contact lens wearers

28

What are common reflexes that initiate reflex blinking?

Dazzle reflex and menace reflex

29

Blephoraspasm

Slow sustained closure to painful stimuli

An idiopathic disorder of neuromuscular control (orbicularis muscle)
Results in simultaneous bilateral, symmetrical, progressive, involuntary closure of both eyes

Raises IOP; Temporary relief with botulinum-A toxin

30

Spontaneous Blinking

blinking that occurs on regular bases withput external stimuli

31

Name conditions in which spontaneous blinking can change?

Can change secondary to level of visual activity, emotional states, and environmental conditions
(Clinical point – Computer users, any activity that involvesincreased attention)

32

Spontaneous Blinking in Infants?

low or absent

33

Spontaneous Blinking in Blind

present; does not depend on optical stimulation

34

Spontaneous Blinking motion

most motion occurs in upper lid; lower lid stationary; palpebral fissure closes laterally to medially flushing tears through puncta

35

Rate of Spontaneous Blinking

Spontaneous blink rate is ≈ 15x per min; Duration of blink is 300-400 msec; Average time between blinks is 2.8 sec

36

Voluntary Blinking

consciously initiation of closure of one eye. Most ppl blink freely with left eye

37

Myokymbia and causes of aggravation?

fibrillary twitching ; fatigue, psychological stress, and thyrotoxicosis

38

Lagophthalmos

incomplete closure of eyes during sleep; results in desiccation and excessive exposure of lower portions of cornea

39

Ectropian

falling away of the lower eyelid away from globe; droopiness

40

What causes ectropian?

weakness of obicularis

41

Results of ectropian?

poor blink closure and epiphora

42

Senile Ectropian

loss of tone and loss of orbital fat

43

Entropian

turning in of eyelid

44

Results of Entropian?

Trichiasis (turning in of eye lashes) ; trachoma (Chlamydia infection) and ocular pemphigoid;

Loss of transparency or cornea (cause it to get opaque)

Autoimmune reaction causes conjunctiva to shrinkScarring and shrinking

45

Palpebral Fissure

8-11 mm wide; 27-30mm long
Proptosis or large eye with shallow pits= larger fissure
Recession of globe= narrow fissure

46

Exophthalmos

Seen 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

47

Exopthalmos Measure

Measurements range from 12 to 21 mm -normal subjects
mean of 16 mm
thyroid eye disease yield values ranging from 12 to 24 mm
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.