ADNEXA Flashcards
1
Q
The orbicularis oculi is innervated by which of the following cranial nerves?
A
CN 7
2
Q
Consider the image. The highlighted area (green) contains which 2 of the following structures?
A
Plica semiluminaris, Lacrimal caruncle
3
Q
Consider the image. Which of the following clinical terms best describes the findings in the image?
A
Distichiasis (inwardly grown lashes)
4
Q
Which of the following structures functions to drain the tears?
A
Lacrimal punctum
5
Q
Know structures that are anterior/posterior to the gray line
A
Which of the following structures is located anterior to the gray line?
Eyelashes (Other choices are: Mucocutaneous junction, meibomian gland openings, plica semiluminaris)
6
Q
Which of the following structures divides the lid into a preseptal part and a pretarsal part?
A
Superior palpebral sulcus
7
Q
Which of the following structures is adherent to the posterior portion of the tarsal plate?
A
Palpebral conjunctiva
8
Q
Which 3 of the following structures are attached to the lateral orbital tubercle?
A
Lateral palpebral ligament, Ligament of Lockwood, Lateral check ligament
9
Q
An anterior displacement of the lids in which of the following locations suggests lacrimal gland enlargement?
A
Superior-temporal
10
Q
Which 2 of the following are functions of the orbital portion of the orbicularis oculi?
A
Forcefully closing the eye, Winking
11
Q
An inward turned eyelid margin is consistent with which of the following clinical terms?
A
Entropion
12
Q
Which of the following structures has tiny fibers that attach to the dermis of the skin creating the superior palpebral sulcus?
A
Aponeurosis of the levator palpebrae superioris
13
Q
Which of the following structures indents the lacrimal gland dividing it into two parts?
A
Aponeurosis of the levator palpebrae superioris
14
Q
Which of the following ophthalmic artery branches is ultimately responsible for supplying the lateral marginal arcades?
A
Lacrimal
15
Q
Which of the following characteristics best describes the secretion of healthy meibomian glands?
A
Transparent oil
16
Q
Which 2 of the following clinical characteristics is consistent with an internal hordeolum?
A
Localized elevated lesion, pain on palpation
17
Q
Which 2 of the following anatomical locations best describes the ends of the conjunctiva?
A
1.0 anterior to the limbus, Mucocutaneous junction
18
Q
Which of the following glands secretes directly into the conjunctival sac?
A
Wolfring
19
Q
Which 2 of the following vessels are in direct communication with the episcleral arterial circle?
A
Conjunctival artery and Episcleral artery
20
Q
Which of the following nerves innervates the inferior palpebral conjunctiva?
A
Infraorbital
21
Q
Which of the following structures divides the lacrimal gland into two lobes?
A
Aponeurosis of the levator palpebrae superioris
22
Q
The postganglionic parasympathetic fibers innervating the lacrimal gland travel with which of the following nerves as they pass through the inferior orbital fissure?
A
Zygomatic
23
Q
The valve of Rosenmuller separates which 2 of the following structures?
A
Common canaliculus, Lacrimal sac
24
Q
Which of the following statements best describes the appropriate movement of the tip of the cannula if irrigating through the inferior punctum?
A
Down 2mm and medial 3-4mm
25
Which of the following terms is an inflammation of the lacrimal sac?
Dacryocystitis
26
The tear layer that lies closest to the cornea is secreted by which of the following glands?
Goblet
27
# Define what each of these lid swellings is, including glands involved, location on lid, and what is wrong with the glands involved:
- external hordeolum
- internal hordeolum
- chalazion
EXTERNAL HORDEOLUM
- also known as a stye, it is a focal, red nodule on the outer surface of the eyelid usually warm and painful to the touch
- acute inflammation of gland of Zeis/Moll
- caused by staphylococcal infection
INTERNAL HORDEOLUM
- another type of stye, acute infection of meibomian gland causing a focal, red nodule on inner eyelid that is usually warm and painful to the touch; usually bursts/heals on its own
- caused by staphylococcal infection
CHALAZION
- chronic, localized non-infectious swelling of meibomian gland; it is a painless, and non-red lump found some distance from the eyelid margin
- caused by blocked duct; the gland continues to produce oil which builds up inside the gland. Eventually, the gland ruptures and releases oil into the tissues of the lid causing a granulomatous inflammation.
28
Which conjunctiva swells more (palpebral or bulbar?), if, for instance, the person has an allergic reaction and why?
Define chemosis
The bulbar conjunctiva swells more than the palpebral conjunctiva since the bulbar conjunctiva is more loosely adherent to the sclera than the palpebral fissure is to its underlying tissues.
Conjunctival capillaries are also fenestrated with diaphragms so the vessels leak plasma faster than they can escape to the surface or via lymphatic vessels.
Chemosis = conjunctival edema caused by the bulbar conjunctival stroma becoming thick with fluid due to inflammation
29
State what the following glands secrete, where they are located in the conjunctiva, what space they drain into, and what layer of the tears their secretions contribute to
- Goblet cells
- Glands of Krause
- Glands of Wolfring
GOBLET CELLS
Secretion: Mucus
Location: in conjunctival epithelium lining fornix and palpebral/bulbar conjunctiva near fornix (conj. epithelium contains stratified columnar epithelium with goblet cells)
Drains into: secrete mucus directly into fornix
Layer contribution: Aqueous-mucin layer
GLANDS OF KRAUSE
Secretion: serous glands secreting watery substance containing proteins (similar to lacrimal gland production)
Location: accessory lacrimal glands located in stroma of conjunctiva; most are in upper fornix, a few in lower
Drains into: directly into superior/inferior fornix
Layer contribution: Aqueous-mucin layer
GLANDS OF WOLFRING
Secretion: similar to gland of Krause
Location: larger than Krause, but fewer in number; most lie in superior palpebral conj. above superior tarsal plate. 2 lie in inferior palpebral conj. near inferior tarsal plate.
Drains into: directly into conjunctival sac
Layer contribution: Aqueous-mucin
30
Which specific blood vessels supply these parts of the conjunctiva and what blood vessels do they originate from:
- palpebral conjunctiva
- fornix conjunctiva
- bulbar conjunctiva
PALPEBRAL CONJUNCTIVA
Marginal arcades formed by the lateral/medial palpebral arteries (through tarsal plate)
Peripheral arcades (through Mueller's muscle) also supply some palpebral conj.
FORNIX CONJUNCTIVA
All of the fornix conjunctiva is supplied by the peripheral arcades through Mueller's muscle; some perforating arteries supplying fornix will rebranch to form posterior conjunctival arteries
BULBAR CONJUNCTIVA
Posterior conjunctiva arteries and anterior conjunctival arteries branching from superficial marginal plexus
***
Anterior ciliary arteries -> two branches (major perforating branch and episcleral artery) -> episcleral arteries anastomose to form episcleral arterial circle -> episcleral arterial circle continue to cornea where it is renamed conjunctival arteries-> conjunctival arteries anastomose to form superficial marginal plexus...
Superficial marginal plexus gives off 2 branches:
- anterior conjunctival arteries = pass posteriorly to supply bulbar conjunctiva
- corneal arcades = near termination of Bowman's membrane; give off fine vascular loops in palisades of Vogt to supply peripheral cornea
31
Name two ways to tell conjunctival blood vessels from scleral blood vessels
Conjunctival blood vessels can be distinguished from deep episcleral blood vessels supplying the sclera using two different methods:
1. by moving the conjunctiva: the superficial conjunctival vessels SHOULD MOVE while the deep episcleral vessels supplying the sclera should NOT move.
2. by using a topical vasoconstrictor: conjunctival blood vessels can be constricted with topical epinephrine, while the deep episcleral vessels that supply the sclera cannot be constricted with topically applied epinephrine.
32
State the location of the lacrimal gland in the orbit, where the lacrimal gland secretes, and which layer of the tears its secretions contribute to
The lacrimal gland lies in the lacrimal fossa (depression on frontal bone located anterior and lateral on orbital roof, inside superior orbital margin). It contains 12 ducts that drain into the lateral part of the superior conjunctival fornix. Its secretions are the major contributor to the aqueous-mucin layer of the tear film
33
Name the two parts of the lacrimal gland, which part lies adjacent to the frontal bone, and what space the ducts of the 2 gland parts drain directly into
The larger orbital portion lies above the levator aponeurosis and contacts orbital roof/lateral orbital wall (adjacent to frontal bone). It sends 2-5 ducts through palpebral portion to drain directly into superior conjunctival fornix.
The smaller palpebral portion lies below the aponeurosis and can be seen by pulling the upper lid superiorly and laterally. It has 6-8 ducts that drain directly and independently into the superior conjunctival fornix.
34
State which gland is the major contributor to the aqueous layer of the tears
Lacrimal gland
35
Which nerve provides sensory innervation to the lacrimal gland?
Sympathetic innervation (pain, temperature, touch) provided by lacrimal nerve (ophthalmic division CNV)
Parasympathetic innervation (secretion)
- cell bodies of preganglionic parasympathetic fibers in superior salivatory nucleus (in pons) = axons in greater petrosal nerve (of facial nerve CN7), pass through pterygoid canal to terminate in pterygopalatine ganglion
- cell bodies of postganglionic parasympathetic lie in pterygopalatine ganglion hitch-hiking on maxillary division CNV onto communicating branch-> lacrimal nerve
36
Damage to the following structures leads to
- loss of preganglionic innervation to the lacrimal gland
- loss of postganglionic innervation to the lacrimal gland
Both would cause loss of lacrimal gland secretion and complaints of dry eye.
"damage to the lateral wall of the orbit could damage the postganglionic parasympathetic fibers traveling to the lacrimal gland leading to loss of lacrimal gland secretion and therefore complaints of dry eye."
37
Sympathetic nerves to the lacrimal gland innervate ______ and cause __________
How would sympathetic innervations of the gland affect lacrimal gland secretion?
Sympathetic innervation of the lacrimal gland is to blood vessels of the lacrimal gland and this causes vasoconstriction.
Therefore sympathetic stimulation might indirectly cause decreased production of
lacrimal gland secretions because of the restricted blood flow to the gland.
38
Trace the path of the tears starting with tears on the cornea and ending in the inferior meatus. Be specific and complete. Describe the location of "valves" along the path and their function.
1. Tears accumulate in conjunctival fornices, lacrimal lake, and as tear meniscus
2. During a blink, the upper lid wipes a thin film of tears across the cornea (lids first meet at lateral canthus continuing medially)
3. Tear meniscus is pushed toward puncta into which they drain via capillary action
4. Tears enter the canaliculi into the common canaliculus-> lacrimal sac-> nasolacrimal duct-> inferior meatus of nasal cavity
39
Because your 70 year old patient is complaining of epiphora and you suspect obstruction in the tear drainage system you decide to check the patient's tear drainage system for blockage by placing an irrigation cannula (attached to a syringe containing saline solution) into the inferior punctum. Then you proceed to enter the ____ by going _____ mm in a _____ (horizontal or vertical?) direction and then _____mm in a (horizontal or vertical?) direction passing through the ______ until you feel it stop. Then you push on the syringe's plunger sending the saline solution into the system.
If the saline comes back out the inferior punctum, where is the blockage most likely located?
If the saline comes back out the superior punctum, where is the blockage most likely located?
"After removing the dilator, the lacrimal cannula is inserted perpendicular to the lid margin, letting it slide downward 2mm into the vertical canaliculus. The syringe is gently turned horizontally so that the cannula is directed nasally. The cannula is inserted into the horizontal canaliculus another 3 to 4mm, keeping the lid slightly taut to allow easy access."
If saline comes back out of the inferior punctum, blockage is likely present in inferior canaliculus.
If saline comes back out of the superior punctum, blockage likely exists in common canaliculus or lacrimal sac.
40
With conjunctivitis, the redness of the bulbar conjunctiva is mainly due to dilation of these blood vessels:
Posterior conjunctival arteries derived from the vasculature of the eyelid and supplying most of the bulbar conjunctiva except anterior 2-3mm
Anterior ciliary arteries supplying the anterior perilimbal part is usually spared.
41
Where is the "lid wiper" located on the eyelid AND what type of epithelium is it covered by? Be specific.
The "lid wiper" is a thin band of thickened palpebral conjunctival epithelium (located just posterior to the mucocutaneous junction) of the upper lid. This strip of palpebral conjunctiva is composed of stratified cuboidal or stratified columnar epithelium with goblet cells. It is most likely held against the eyeball by muscle of Riolan.
42
Define dacryocystitis and dacryoadenitis
Dacryocystitis = inflammation of lacrimal sac (pt presents with pain, redness, swelling on medial aspect of lower lid overlying lacrimal sac; usually due to nasolacrimal duct obstruction -> bacterial infection in lacrimal sac
Dacryoadenitis = inflammatory enlargement of lacrimal gland may be of viral/bacterial origin but usually systemic if present bilaterally (sarcoidosis, lymphoma, Sjogren, malnutrition); palpebral part is often involved and pt. has pain, redness, swelling (as well as in preauricular lymph nodes)
43
(CO) 1. Identify and describe the glands of the eyelids including (but not limited to): location, type of gland it is (e.g. sweat, sebaceous), drainage points (if discussed in class), substances secreted, clinical aspects (internal vs. external hordeolum and chalazion), contribute to tear layer?
- Glands of Zeis
- Glands of Moll
- Meibomian glands
- Be able to identify glands of the lids on a lid diagram
see previous question
GLANDS OF ZEIS = sebaceous (miniature meibomian); opens into hair follicles (oil keeps lashes moist)
GLANDS OF MOLL = apocrine sweat gland at eyelid margin (large lumen-> secrete hypotonic watery solution with low protein); opens into gland of Zeis duct, hair follicle, or lid margin
MEIBOMIAN GLANDS = sebaceous glands embedded in tarsal plate of upper/lower lids
44
(CO) 2. Identify and describe the conjunctiva including its 3 parts, locations, blood supply and innervation of the 3 parts
- identify the conjunctival parts on a diagram
- describe what each part of the conjunctival epithelium is directly continuous with (e.g bulbar conjunctiva directly continuous with corneal epithelium)
- be able to state where the bulbar conjunctiva extends most posteriorly from the limbus
- compare bulbar and palpebral conjunctiva in terms of tightness vs. looseness of its attachments and clinical significance
- state which fornix is the deepest and which fornix is the largest
Conjunctiva overall innervated by ophthalmic and maxillary division of CNV
> BULBAR CONJUNCTIVA (non-keratinized stratified squamous)
- covers anterior portion of Tenon's capsule, continuous with fornix (extends farthest from limbus temporally)
- loosely adherent to underlying tissue everywhere except anterior 3mm tightly adherent and fuses with cornea
- blood supply: posterior conjunctival arteries, anterior conjunctival arteries branching from superficial marginal plexus
- innervated by long posterior ciliary nerves (branches of nasociliary n.) and short posterior ciliary nerves
> FORNIX/PALPEBRAL CONJUNCTIVA
Palpebral conj cell type = non-keratinized stratified squamous
Fornix cell type = stratified columnar with goblet cells
Palpebral conjunctiva blood supply: marginal arcades perforating through tarsal plate and peripheral arcades (some)
Fornix blood supply: peripheral arcades (through Mueller's muscle)
Superior part innervated by: branches of ophthalmic division CNV (lacrimal, supraorbital, supratrochlear, infratrochlear)
Inferior part innervated by: infraorbital nerve (branch of maxillary div, CNV)
> At the lid margin (mucocutaneous junction), the palpebral conj. epithelium is continuous with the epithelium on the skin of the lid. At the limbus, the bulbar conjunctiva epithelium is continuous with the corneal epithelium
> Temporally, the bulbar conj. extends most posteriorly from the limbus (fornix is also deepest here)
> Differences between bulbar and palpebral conj. : see previous question on anatomical reason why person's bulbar conj. swells more than palpebral conj. during allergic reaction, inflammation-> chemosis
> The temporal (lateral) fornix is the deepest since it extends posterior to the equator of the eyeball while the superior fornix is the largest in size and volume
45
Clinical aspects:
- How do you distinguish conjunctival vs. deep episcleral blood vessels on a patient?
- Define chemosis
- Which blood vessels are involved leading to bulbar conjunctival injection with conjunctivitis? Anterior or posterior conjunctival arteries or both?
> Conjunctival blood vessels can be distinguished from deep episcleral blood vessels supplying the sclera using two different methods:
1. by moving the conjunctiva: the superficial conjunctival vessels SHOULD MOVE while the deep episcleral vessels supplying the sclera should NOT move.
2. by using a topical vasoconstrictor: conjunctival blood vessels can be constricted with topical epinephrine, while the deep episcleral vessels that supply the sclera cannot be constricted with topically applied epinephrine.
> chemosis = when the bulbar conjunctival stroma becomes thick with fluid leading to conjunctival edema
> Posterior conjunctival arteries are the ones typically involved in conjunctival injection
46
(CO) 3. Identify and describe the conjunctival glands, including their locations, secretions, type of gland (serous, sebaceous, sweat, mucus), contribution to tear layer, drainage points
- Glands of Krause
- Glands of Wolfring
- Goblet cells and where most numerous
see previous question
```
GOBLET CELLS (density greatest in the fornix conjunctiva)
KRAUSE/WOLFRING (majority of glands in upper fornix)
```
47
(CO) 4. State the type of epithelium found in the following locations on the lid and elsewhere and what epithelia they are directly continuous with:
- skin side
- palpebral conjunctiva near lid margin vs. near fornix
- lid wiper part of palpebral conjunctiva
- fornix
- bulbar conjunctiva near limbus vs. near fornix
LID SKIN: epithelial layer (keratinized stratified squamous), dermis (elastic fibers), hypodermis (absent)
PALPEBRAL CONJUNCTIVA
near lid margin: non-keratinized stratified squamous
near fornix: stratified columnar with goblet cells
LID WIPER: stratified cuboidal or stratified columnar with goblet cells
FORNIX: stratified columnar with goblet cells
BULBAR CONJUNCTIVA
near limbus: non-keratinized stratified squamous
near fornix: stratified columnar with goblet cells
48
(CO) 5. Identify and describe the lacrimal apparatus and its component parts in detail and functions. Be able to identify parts on a diagram. Include
- Lacrimal gland: location, parts and what indents to get the two parts, point of drainage of orbital and palpebral parts, secretions, innervation, layer of tears it secretes
- Puncta: structure, location, functions, what they drain into, when are they visible? What keeps them open? What presses them in towards lacrimal lake?
- Canaliculi: structure (including horizontal and vertical parts and their length, ampulla, common canaliculus), location, relative to anterior limb of the MPL, function, points of drainage, what structures the canaliculu interconnect, what prevents reflux from lacrimal sac back into the common canaliculus and therefore the canaliculi?
- Valve of Rosenmuller: location and function
- Lacrimal sac: structure including length, location, anatomical relationships to anterior limb of MPL, Horner's muscle, lacrimal crests and periorbita; function; drainage
VALVE OF ROSENMULLER
There may be a mucosal fold at the point of entry of the common canaliculus into the lacrimal sac (valve of Rosenmuller), preventing reflux of fluids from the lacrimal sac into the common canaliculus and subsequently into the canaliculi and punctum.
LACRIMAL SAC
> "blind" upper end of nasolacrimal duct in the "fossa for the lacrimal sac" formed by lacrimal and maxilla bone
> bound by anterior/posterior lacrimal crests and enclosed in periorbita
> upper part bounded anteriorly by anterior limb of medial palpebral ligament (attaches to anterior lacrimal crest) and posteriorly by posterior limb of medial palpebral ligament)
> Horner's muscle lies posterior to posterior limb of MPL and attaches to posterior lacrimal crest + periorbita surrounding upper part of lacrimal sac
49
(CO) 6. Be able to discuss why a patient might need the D & I procedure and interpretation of results of D & I procedure discussed in class, such as:
- What it means if saline tasted at back of patient's throat?
- Where might the blockage be in the tear drainage system if the saline comes back out of the inferior punctum or superior punctum?
- Be able to describe the path the lacrimal cannula takes starting at the inferior punctum and ending at the lacrimal sac. Include orientation of the canaliculi and their lengths.
D&I = dilation and irrigation
WHY USED: to see if nasolacrimal drainage system is blocked if patient is present with epiphora
RESULTS:
> saline tasted at back of throat: the saline flowed through the system unimpeded
> saline regurgitates out of superior punctum: blockage most likely in common canaliculus or lacrimal sac
> saline regurgitates out of inferior punctum as it is irrigated: blockage most likely in inferior canaliculus
see previous question
50
(CO) 7. Define dacryoadenitis and dacryocystitis
see previous question
51
(CO) 8. Be able to discuss congenital nasolacrimal duct obstruction including symptoms, causes, and treatment
SYMPTOMS
primary cause of excessive tearing in infants/young children (may be mucopurulent discharge from puncta)
CAUSES
blockage of the lacrimal system most often at the extreme distal end of the nasolacrimal duct (where valve of Hasner is located)
TREATMENT
usually self-limiting within 6 months to a year
treatment include massage of lacrimal sac region, warm compress to skin overlying lacrimal sac, topical antibiotics
if does not resolve, "probing" of the duct to open the blockage may be needed
52
(CO) 9. Describe how tears are distributed over the cornea with a blink and in general how the tears drain into the nasal cavity as described on pg. 206.
- Include which part of the palpebral fissure closes first and last (medial or lateral or both simultaneously) (i.e. be able to trace the tears from the conjunctival sac to the nasal cavity)
- Be able to discuss the role of the lid wiper part of the palpebral conjunctiva in tear distribution
- Define "lid wiper syndrome" and its side effect
- What is the tear meniscus?
- What does a thin or absent tear meniscus suggest/indicate about the patient's eyes?
LID WIPER SYNDROME
Some patients who wear silicone hydrogel lenses (soft contact lenses that allow more oxygen to the cornea) develop lid wiper syndrome. With this syndrome the edge of the contact lens irritates the lid wiper portion of the palpebral conjunctiva with each blink. Thus the affected contact lens wearer develops dry eye since the lid wiper is impaired and now cannot properly distribute the tear film on the surface of the eye.
53
(CO) 10. Describe the 2 layers of the tear film. Be sure to include:
- Names of the two layers of the tear film from anterior to posterior
- What glands secrete the lipid, aqueous, and mucus components of the tear film
LIPID LAYER
secreted by meibomian glands and to slight extent by glands of Zeis at eyelid margin (superficial to aqueous-mucin layer); provides stability to tear film
AQUEOUS-MUCIN LAYER
closest to cornea; mixing between the two layers creating gradient. It is a hydrated gel with the aqueous component secreted by lacrimal gland and accessory glands of Krause and Wolfring. Mucin component is secreted by goblet cells in conjunctival epithelium and near fornix.
54
When the eyelids are open, where should they lie relative to the eyeball?
- Superior lid
- Inferior lid
The superior eyelid should lie 1.5-2.0 mm below the superior limbus (thus covering a portion of the superior cornea)
The lower eyelid position is more variable and generally lies at the level of the inferior limbus (or at least within 1 mm of the limbus).
55
What creates the superior palpebral sulcus? Be specific.
The superior palpebral sulcus is formed by the insertion of levator palpebrae superioris aponeurosis into the skin of the upper eyelid. It is much less apparent when the eyelid is closed.
56
Define lagophthalmos and symptoms associated with it
"Hare" eye; it is an inability to close the eyelids completely. Inferior bulbar conjunctiva, sclera may be visible since the patient has an incomplete blink.
The tears are not able to wash away debris and keep the epithelial cells lubricated & nourished in the exposed areas during the day and while sleeping. Thus the patient may be complaining of dry, irritated eye especially in inferior bulbar conj and cornea.
57
What are the functions of the orbital and palpebral parts of orbicularis oculi? And which muscles are their antagonists?
```
ORBITAL PART
Outermost circumferential fibers overlying frontal, maxillary, zygomatic bones ORIGINATING from maxilla, frontal bone, and anterior surface of medial palpebral ligament (MPL) and ENDING at lateral palpebral raphe.
Functions include:
-closing eye forcefully and winking
Antagonist = frontalis muscle
```
PALPEBRAL PART
Consist thin concentrically arranged fibers anterior to the tarsal plate and orbital septum. The fibers ORIGINATE from medial palpebral ligament (MPL) and END in lateral palpebral raphe (where superior/inferior palpebral fibers interdigitate).
Functions include:
closes the eye gently as during sleep, used for involuntary and reflex blinking, and assisting muscle of Riolan in keeping eyelid apposed to the globe
Antagonist = levator palpebrae superioris
58
Explain what happens during a blink...i.e. what muscle is inhibited and which is contracting?
During a blink the levator palpebrae superioris is inhibited and the orbicularis oculi is activated (based on Sherrington’s law of reciprocal innervation which states contraction of a muscle is accompanied by a simultaneous proportional relaxation of its antagonist)
59
State all the structures that attach to the superior tarsal plate on its
- upper margin
- anterior surface
Upper margin = superior Muller's muscle (superior tarsal muscle)
Anterior surface = aponeurosis of levator palpebrae superioris (allowing it to raise the upper eyelid)
*
- The anterior surface of the superior tarsal plate is separated from the palpebral part of orbicularis oculi by the aponeurosis of levator palpebrae superioris
- The posterior surface of both the superior & inferior tarsal plates is adherent to the palpebral conjunctiva
60
Name the structures seen at the eyelid margin beginning anteriorly with the eyelashes and ending posteriorly
Eyelashes-> Muscle of Riolan-> Palpebral part Orbicularis oculi-> Aponeurosis of levator palpebrae superioris/orbital septum-> tarsal plate with meibomian gland embedded->superior Mueller's muscle-> fornix-> bulbar conjunctiva
61
What is the plica semiluminaris and what does it allow during eye movement? What is the caruncle?
Slack, vertical semilunar fold of bulbar conjunctiva by the medial canthus that lies lateral & slightly posterior to the caruncle.
-It forms the floor of the lacrimal lake
-It is loose and redundant allowing the eye to move more fully laterally without
stretching bulbar conjunctiva (i.e. it does not limit movement of the eyeball during abduction of the eye)
The caruncle is a 8-10 layer structure of pinkish modified skin (made of non-keratinized stratified squamous epithelium) medial to the plica semiluminaris. It contains goblet cells, Langerhans cells, fine hairs and associated sweat & sebaceous glands and loose CT.
62
State which lid structures attach to the:
- anterior lacrimal crest
- posterior lacrimal crest
- lateral orbital tubercle
Anterior lacrimal crest- the anterior limb of the medial palpebral ligament (MPL) (anterior limb also lies anterior to the lacrimal sac and thus to the canaliculi that drain into the lacrimal sac)
Posterior lacrimal crest- the posterior limb of the medial palpebral ligament
Lateral orbital tubercle- lateral palpebral ligament (LPL) runs from the lateral edge of the tarsal plates to the lateral orbital tubercle on the zygomatic bone
63
Name the structures that lie medially starting with the palpebral part of the orbicularis oculi and ending with the posterior lacrimal crest
Palpebral part of the orbicularis oculi-> anterior limb medial palpebral ligament (MPL)-> lacrimal sac and canaliculi-> posterior limb medial palpebral ligament (MPL) (attaches to posterior lacrimal crest) -> Horner's muscle (posterior to posterior limb of MPL and to posterior lacrimal crest/periorbita surrounding lacrimal sac)
64
Describe all major structures in the lid starting anteriorly with skin and ending posteriorly with the palpebral conjunctiva
Skin (thin skin which includes epidermis & dermis; hypodermis is very attenuated or absent in thin skin)
```
Skeletal muscle – orbicularis oculi
Orbital part orbicularis oculi muscle
palpebral part orbicularis oculi muscle
separated from the tarsal plate by the aponeurosis of levator palpebrae superioris
muscle of Riolan – at the eyelid margin
```
Orbital septum/tarsal plate
– Meibomian glands embedded In tarsal plates
Smooth muscle- Mueller’s muscle
Palpebral conjunctiva
65
Lid symptoms if the following nerves are damaged:
- facial nerve
- oculosympathetic fibers
Facial Nerve: Causes of lagophthalmos may be physiologic, mechanical (i.e. scarring), exophthalmos, or may occur following weakness or paralysis of the facial nerve (CN VII).
Oculosympathetic fibers: Horner's syndrome
With damage to neurons of the oculosympathetic pathway (Horner’s syndrome), there is:
1-2 mm ptosis and the patient may have a smaller palpebral fissure since the
superior Mueller’s muscle droops down and the inferior Mueller’s muscle likewise
is raised upward as much as 1 mm.
Additionally the pupil cannot dilate so the pupil is smaller on the affected side.
This could be due to damage to central, preganglionic and/or postganglionic sympathetic fibers of the oculosympathetic pathway.
66
What blood vessels supply the eyelids and which vessels do they arise from?
The eyelids are supplied by the lateral and medial palpebral arteries.
- lateral palpebral arteries arise from the lacrimal artery
- medial palpebral arteries arise from the ophthalmic artery
In turn... The palpebral arteries each form two arcades that meet somewhere in the middle of the eyelid
- marginal arcades lie near the eyelid margin
- peripheral arcades lie farther, near superior edge of the superior tarsal plate & inferior edge of inferior tarsal
- anterior network supplies lid itself; posterior supply palpebral conj.
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Define a canthus and state what meets at each (i.e. state how they are different)
Canthus (pI. canthi; kanthos= "corner of the eye") = the place (angle) where the upper and lower eyelids meet
- at the lateral canthus (lateral angle of eye), the eyelids ARE in direct contact with the eyeball
- at the medial canthus (medial angle of eye) the eyelids are NOT in direct contact with the eyeball due to the presence of the lacrimal lake.
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What nerves provide sensory innervation to the upper lid? Be specific. Which pierce the orbital septum to reach the upper lid? Which nerve(s) provide(s) sensory innervation to the lower lid? Any pierce the orbital septum?
UPPER LID supplied by branches of ophthalmic division CNV: lacrimal*, supraorbital, supratrochlear*, infratrochlear* nerves
(other parts supplied by ophthalmic div: short/long posterior ciliary arteries and external nasal)
LOWER LID supplied by branches of maxillary division CNV: infraorbital nerve
(other parts = zygomaticofacial/temporal)
Pierce the orbitum septum: lacrimal, supratrochlear, infratrochlear nerves
Vessels piercing septum = lacrimal, supratrochlear, dorsal nasal, medial palpebral
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Why does lid edema occur during lid trauma? In a young person's lid why can the lid recover to normal after being stretched by the edema?
The thinness of the lid skin and the looseness of the underlying dermis allow the lid to be greatly distended (stretched) as seen in patients with a black eye (ecchymosis) or preseptal cellulitis. But the skin quickly recovers (usually with no residual skin folds) after being stretched (such as by edema), due to the dermis’ elasticity.
However this elasticity decreases with advanced age so that stretching of the eyelid skin will cause exaggerated /redundant skin folds referred to clinically as dermatochalasis.
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Define distichiasis and madarosis
Distichiasis is the term used for the presence of extra rows of eyelashes. This condition can affect the upper & lower eyelids. These lashes often emerge from the meibomian gland orifices. Most cases are congenital but acquired (chemical burn, SJS, blepharoconjunctiitis) cases can be encountered as well.
-can cause irritation, epiphora, corneal abrasion, ulcers
Madarosis = loss of eyelashes (can be due to blepharitis, autoimmune alopecia areata, etc.)
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(CO) 1. State the effect frontalis and orbital part of orbicularis oculi have on the eyebrows when the muscles contract. (i.e. whether they elevate or depress the eyebrows) and their innervation
FRONTALIS = raises the eyebrow
ORBITAL PART= depresses the eyebrow
both innervated by facial nerve
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(CO) 2. Describe the external appearance of the eye and eyelids by identifying the following structures. Include what each of the following structures is, its function if one is stated:
- which lid is larger
- normal position for the upper and lower eyelid when eyes are open vs. exophthalmos
- appearance of the lid with lagophthalmos
- position of lids when the eyes are greatly closed (which covers cornea more? Should whole globe be covered?)
- medial and lateral canthus
- lacrimal lake
- pretarsal vs. preseptal (orbital) parts of the lid
- superior palpebral sulcus AND what creates the sulcus
- lacrimal caruncle and plica semiluminaris including what they are and their location (innervation of caruncle/function of plica semiluminaris)
- definition of palpebral fissure
- superior lid is larger
- normal position listed in previous question
- exophthalmos: if sclera is seen above the cornea, then the upper eyelid must be retracted and possible causes could include exophthalmos due to hyperthyroidism, orbital mass, etc.
- lagophthalmos: the sclera above lower lid as well as lower palpebral/bulbar conj can be seen. If no Bell's phenomenon cornea would be exposed.
- upper lid covers cornea more and whole globe is covered
- lateral canthus (eyelids in direct contact with eyeball), medial = no due to lacrimal lake
- pretarsal/preseptal division by superior/inferior palpebral sulci-> "pretarsal" (closest to lid margin, contains tarsal plate, skin is thin and tight); "preseptal" (extends from palpebral sulcus to eyebrow and associated with orbital septum; skin loosely adherent)
- superior palpebral sulcus = upper eyelid crease (formed by insertion of LPS aponeurosis into skin of upper lid)
- plica = semilunar fold of bulbar conj. by medial canthus that forms floor of lacrimal lake; loose and allows eye to move more fully laterally without stretching bulbar conj.
- palpebral fissure = elliptical area between the eyelids
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(CO) 3. Identify and describe the upper & lower eyelid margins & associated
structures including their location, function if one is stated:
-the eyelashes, gray line (and its significance), meibomian gland openings, lacrimal punctum (and function), mucocutaneous junction
-describe the anatomical relationships (i.e. anterior or posterior to what) of the structures at the lid margin
see previous question
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(CO) 4. Describe the eyelid including:
- its component parts from anterior to posterior
- be able to identify its parts on a sagittal section through the eyelid
- the anatomical relationships of its parts (such as anterior vs. posterior)
- motor & sensory innervation of the eyelid
see previous question
MOTOR INNERVATION
Orbicularis oculi = CN7
Superior and inferior Mueller's muscles = postganglionic sympathetic fibers hitch-hiking on CN3; and LPS innervated by superior division CN3
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SENSORY INNERVATION
Upper lid (branches of ophthalmic div. CN5-> lacrimal/infraorbital/infratrochlear/supratrochlear)
Lower lid (branches of maxillary div. CN5)-> infraorbital
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(CO) 5. Describe the skin of the lids including thinness, epithelium, dermis, location where fat absent, clinical aspects of dermis as discussed in class relative to lid edema)
Thinnest skin of the body
Epithelium made of keratinized stratified squamous epithelium containing all four layers including THIN stratum corneum.
Dermis has many elastic fibers (reticular layer) allowing skin to be stretchy which is bad for edema but good for recovery
Hypodermis is absent in eyelid skin so NOT FAT in eyelid skin
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(CO) 6. Identify & describe the orbital septum including its: functions, attachments, structures that pierce it, location & relationship to the periorbita and anatomical relationships to other eyelid or orbit parts (i.e. aponeurosis of levator palpebrae superioris, tarsal plate, fat pads, what does it lie anterior & posterior to?)
- Why no fat pad is located laterally in superior lid and clinical significance
The orbital septum separates eyelid contents from orbital contents- prevents spread of blood/inflammation from eyelid to orbit; holds orbital fat in position in orbit. It is continuous with periorbita of FMZ bones at orbital margin.
In the upper eyelid the orbital septum does not insert into the tarsal plate; rather it inserts into the aponeurosis of levator palpebrae superioris ~2-5mm mm above the superior border of the tarsal plate as the levator aponeurosis extends into the superior eyelid & interposes itself between the septum & superior border of tarsal plate.
In the lower eyelid the orbital septum fuses with the fascia of the inferior Muller’s muscle 4-5 mm from the inferior border of the tarsal plate and then together they insert into the inferior border of the tarsal plate.
The orbital septum is pierced by Lacrimal, supratrochlear & infratrochlear nerves and Lacrimal, supratrochlear, dorsal nasal & medial palpebral arteries.
These fat pads lie within the orbit but external to the extraocular muscles and serve as a protective cushion for the eyeball as it moves.
There is no lateral fat pad superiorly because the lacrimal gland lies in the lacrimal
fossa located superior- laterally in the anterior part of the obit (near the orbit margin). – So if there is a bulge in the lateral part of the superior eyelid it probably indicates an enlarged lacrimal gland and not a fat pad herniating through the orbital septum
and into the eyelid.
The effectiveness of the orbital septum to hold back the fat pads decreases with age so the fat may herniate into the lid creating a bulge in the lid, but usually not superior-temporally.
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(CO) 7. Identify and describe the tarsal plates including function, composition, size, structures
that attach to or originate from them and where attached (anterior surface of tarsal plate? superior or inferior margin of tarsal plate?) and anatomical relationships such as what lies anterior & posterior to them.
Crescent-shaped structures composed of dense fibrous connective tissue. Give firmness and shape to the eyelids and act as a rigid structure to which muscles attach.
They extend along the lid margin across the width of the lids and their curved peripheral edges roughly follow the contour of the orbital margin; they are curved to fit the contour of the eyeball (like windshield wiper blades on a car).
The anterior surface of the superior tarsal plate is separated from the palpebral part of orbicularis oculi by the aponeurosis of levator palpebrae superioris
The posterior surface of both the superior & inferior tarsal plates is adherent to the palpebral conjunctiva
Superior tarsal plate larger than inferior and attaches to superior Mueller's muscle at upper edge/margin. Aponeurosis of LPS attaches to anterior surface.
Inferior tarsal plate = the orbital septum, inferior Muller’s muscle (inferior tarsal muscle), fascia of
the inferior rectus & fascia of the suspensory ligament of Lockwood attach to its lower edge/margin
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(CO) 8. Identify and describe the medial and lateral palpebral ligaments including origin, insertion and anatomical relationships, especially what structure(s) the MPL lies directly anterior to
Medial palpebral ligament (MPL) runs from the medial edge of the tarsal plates to the medial orbital rim where it divides into anterior & posterior limbs.
Its posterior limb attaches to the posterior lacrimal crest. Its anterior limb attaches to the anterior lacrimal crest. Its anterior limb lies anterior to the lacrimal sac (and therefore it also lies anterior to the canaliculi that drain into the lacrimal sac)
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(CO) 9. Identify and describe the muscles of the eyelids (orbicularis oculi & all its parts, Mueller’s, levator palpebrae superioris) including their attachments, actions, innervation and anatomical relationships in the lid, signs & symptoms if damaged.
ORBICULARIS OCULI
Attachments = originate in MPL and insert into lateral palpebral raphe
Actions = closes the eyelids (compare ocular/palpebral)
Innervation= CN7
Relationships= assists muscle of Riolan
MUELLER'S *smooth muscle
Attachments =
Superior = originate from inferior surface of LPS and insert into upper margin of superior tarsal plate
Posterior = originate from inferior rectus muscle sheath where it surrounds inferior oblique; inserts into lower bulbar conj/lower margin of inferior tarsal plate
Actions = raising the upper eyelid or lowering lower lid, respectively
Innervation= postganglionic sympathetic fibers hitch-hiking on superior/inferior CN3
Relationships=
LPS (skeletal muscle)
Attachments =
-posterior fiber insert into lower anterior surface of superior tarsal plate
-anterior fiber pass between bundles of orbicularis to insert into upper eyelid skin
-lateral attach to lateral orbital tubercle and upper part of lateral palpebral ligament
-medial attach to medial palpebral ligament/medial orbital rim
Actions = raise upper eyelid
Innervation= oculomotor nerve (CN3)
Relationships= originate from lesser wing sphenoid above optic canal, passes through orbit superior to SR muscle; aponeurosis expand and fuses with orbital septum above superior tarsal plate and extends into upper lid
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(CO) 10. Additionally be able to:
- Name the antagonists of the palpebral & orbital parts of orbicularis oculi
- Describe what happens during a blink (i.e. what muscles contract and which are inhibited)
- Define ectropian and state what muscles or nerves are not functioning to cause it. Symptoms of occurs and why?
- Define entropian and state what causes and symptoms, side effects if happens
- Define madarosis
- Define distichiasis
ECTROPIAN
Ectropian = outward turning of the eyelid margin
-more common in lower lid
-usually due to loss of muscle tone in muscle of Riolan and/or palpebral part
orbicularis oculi due to aging or CN VII damage but it can also be due to chemical
burns, scarring of the eyelid skin, eyelid tumors, etc.
-the eyelid margin is no longer up against the eyeball so that the inferior punctum is no longer in a position to drain tears from the lacrimal lake
-leads to epiphora = overflowing of tears onto the cheek
ENTROPIAN
Entropian = inward turning of the eyelid margin
- more common in lower lid
- due to spasm of orbicularis oculi, aging, conjunctival scarring (secondary to trauma or
chemical burns, etc.)
With aging (the most common cause) there is atrophy of the inferior eyelid retractors that attach to the inferior edge of the inferior tarsal plate. So when the orbicularis oculi muscle contracts it pulls the eyelid margin inward.
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(CO) 11. State what blood vessels supply the lids and the origin of the vessels
see previous question
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(CO) 12. Describe sensory innervation to the upper and lower eyelids and specific areas of lid
innervated by nerves of the upper lid
see previous question
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(CO) 13. State which structures attach to the:
- anterior lacrimal crest
- posterior lacrimal crest
- lateral orbital tubercle
Lateral palpebral ligament (LPL) runs from the lateral edge of the tarsal plates to the lateral orbital tubercle on the zygomatic bone
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