Oculoplastics Flashcards
Which bones make up the medial orbital wall?
“SMEL”
• Sphenoid, lesser wing bone
• Maxillary bone
• Ethmoid bone
• Lacrimal bone
Which bones make up the orbital roof?
• Frontal bone
• Lesser wing of sphenoid bone
Which bones make up the orbital floor?
“Zip My Pants”
• Zygomatic
• Maxillary
• Palatine (thinnest)
Which bones make up the orbital lateral wall?
• Greater wing of sphenoid
• Zygomatic
What is a dermoid cyst?
• Lined by keratinizing epidermis with dermal
appendages
• Common pediatric periorbital mass
• Occurs when ectoderm tissue is pinched between
closing bony sutures during embryologic
development → trapped tissue forms cyst
• Type of choristoma
• 5% spontaneously rupture
• Most commonly at the frontozygomatic suture
(supratemporal)
• Second most commonly at the frontoethmoidal
suture (superomedially)
• Dumbbell appearance if they straddle across the
suture line with components inside and outside the orbit
• Treatment: Remove entire cyst with its capsule
because remnants left behind can induce severe
inflammation
What is the most common presentation and treatment of benign orbital tumor in adults?
• Cavernous hemangioma
○ Vascular tumor made of large endothelial-lined
vascular spaces enclosed within fibrous capsule
• Presents as painless progressive proptosis
• Treatment: Surgical removal is indicated if mass is
causing functional impairment (i.e. optic nerve
compression, diplopia, strabismus, substantial proptosis)
What is the most common benign orbital tumor in children and its presentation?
• Capillary hemangioma
○ Small endothelial-lined vascular spaces
contained within fibrous capsule
• Initially grows for several months then
spontaneously involutes or regresses
What is the definition and example of a choristoma?
Definition
• Histologically normal tissue in an abnormal location
Example
• Dermoid cyst
What are the diagnostic tests for myasthenia gravis (MG)?
• Ice pack testing
• Tensilon testing
• Anti-acetylcholine receptor antibodies (binding,
blocking, modulating) → present in 90% of systemic
MG and 70% of ocular MG
What are the clinical findings in blepharophimosis syndrome (BPES)?
Common clinical findings
• Blepharophimosis
• Telecanthus
• Severe ptosis → limited levator function
• Epicanthus inversus
• Deprivation, strabismic, or refractive amblyopia
• Type 1 BPES have early ovarian failure
Other less common clinical findings
• Hypertelorism
• Ectropion
• Hypoplasia of superior orbital rims
What is acute dacryoadenitis?
● Inflammation of lacrimal gland
● Most common cause overall is sterile inflammatory disease
○ Most common viral cause is EBV
What is the average volume of the adult orbit?
30 mL (cubic centimeters)
What is the most commonly injured extraocular muscle in cosmetic eyelid surgery?
● Inferior oblique
○ Inferior oblique divides central and medial fat
pads of lower eyelids
What is a sub-orbicularis oculi fat (SOOF) lift?
Suspends fat pad underneath orbicularis muscle in the
lower eyelid and anterior to orbital septum to improve
contour of lower eyelid, especially as part of midface lift.
What is the most common malignant lacrimal gland tumor and associated common findings?
• Adenoid cystic carcinoma
Associated with
• Lot of pain
• Swiss cheese pattern on pathology
What is the definition of epilation? What is the rate and chance of eyelash regrowth?
Definition
• Removing misdirected lashes with forceps
Rate of eyelash regrowth
• Occurs in 3-6 weeks
Chance of eyelash regrowth
• 100% chance of regrowth
How is radiofrequency ablation to eyelashes performed and what are its side effects?
• Uses a radiofrequency probe
• Slides down individual hair follicle shafts
• Energy delivered is concentrated to the hair follicle
and limits collateral damage
• If probe is moved during active treatment or several
closely clustered lashes are treated, could create a
notch in the lid margin
How is electrolysis to eyelashes performed and what are its side effects?
• Similar to radiofrequency ablation
• Fine wire is introduced into individual hair shaft
• High frequency electrical current is used to
coagulate the follicle
• Causes more scarring and has higher risk of notching
compared to radiofrequency ablation
How is argon laser treatment to eyelashes performed and what are its side effects?
• Similar to radiofrequency
• Focused argon laser beam is used to thermally
destroy the individual hair follicle shafts
• Thick, dark hairs growing from pale skin have the
best uptake of energy and the highest success rates
• Concentrated energy helps limit collateral damage
• Result in notching if several closely clustered lashes are treated
How is cryotherapy to eyelashes performed and what are its side effects?
• Uses sub-zero temperature to freeze eyelid margin
• Prevents lashes regrowth by killing hair follicle cells
• Best for treating broad areas of clusters of lashes
(segmental trichiasis)
• Can lead to thinning of eyelid, loss of meibomian
glands and goblet cells, and skin depigmentation
What is the most common cause of necrotizing fasciitis and its treatment?
● Group A streptococcus
○ Tracks along the fascia
○ Spreads more quickly than typical bacteria and
causes more damage
● Treatment
○ Intravenous antibiotics and urgent surgical
debridement
Where does the levator aponeurosis attach in relation to the tarsal plate for Caucasian patients?
● Levator aponeurosis attaches to the lower one-half
of the anterior surface of tarsal plate
○ Sends projections to skin and orbicularis, which
help anchor the upper lid crease
What is the location and innervation of Muller’s muscle?
• Originates at the under-surface of the levator
muscle and extends a few millimeters down to the
anterior surface tarsus
• Inserts at superior border of tarsal plate
• Innervated by the sympathetic nervous system and
helps maintain the resting tone that holds the upper
eyelid open
What are the seven diagnostic criteria for neurofibromatosis type 1 (NF1) and how many criteria have to be met for diagnosis?
Criteria for NF1 diagnosis
• Six or more cafe-au lait spots
• Two or more axillary or inguinal freckles
• Two or more typical neurofibromas or one plexiform
neurofibroma
• Optic nerve glioma
• Two of more Lisch nodules or iris hamartomas
• Sphenoid dysplasia (causes pulsatile exophthalmos)
or long bone abnormalities
• First degree relative with NF1
Diagnosis
• Requires meeting 2 or more of the criteria above
What percentage of clinically symptomatic congenital nasolacrimal duct obstructions resolve in the first year of life?
By 1 year of age, 70-90% will resolve on their own
What are the most and least common locations for periocular basal cell carcinoma?
• Lower eyelid (50-60%)
• Medial canthus (25-30%)
• Upper eyelid (15%)
• Lateral Canthus (5%)
What are common causes of bilateral proptosis in children?
• Thyroid-associated ophthalmopathy
• Idiopathic orbital inflammation
• Metastatic neuroblastoma
• Leukemic infiltrates
What is a Fasanella-Servat procedure and when is it used?
• Tarsoconjunctival mullerectomy
• Treats mild amounts of ptosis (< 2 mm)
What are the indications for orbital decompression in thyroid eye disease?
• Exposure keratoconjunctivitis
• Compressive optic neuropathy
What is the function of the pretarsal portion of the orbicularis?
Reflex eyelid closure
What are the functions of the preseptal portion of the orbicularis?
Voluntary and reflex blinking
What is the function of the orbital portion of the orbicularis?
Voluntary eyelid closure
What are the classifications of eyelid melanoma and their descriptions?
Tumor thickness Breslow Depth:
1. Melanoma in situ: fully within epidermis
2. Thin/early melanoma: depth < 0.8 mm
3. Intermediate melanoma: depth 0.8 mm to 4 mm,
and/or ulceration. Higher risk of metastatic spread.
Lymph node biopsy recommended
4. Thick melanoma: > 4 mm. High risk of metastatic
spread. Obtain lymph node biopsy. < 50% survival at 5 years
5. Advanced melanoma: spread beyond original tumor site
How many millimeters does Muller’s muscle elevate the eyelid?
2 mm
How is Muller’s muscle innervated?
Sympathetic nervous system
What are the common causes, workup, and treatment of hemifacial spasm?
Most common cause
• Facial nerve compressed as it exits the brainstem by
ectatic vertebral artery or anterior inferior cerebellar artery
Other causes
• Stroke
• Multiple sclerosis
• Trauma
• Cerebellopontine tumor
Workup
• MRI/MRA of head and neck
Treatment
• Botox injections and Jannetta procedure to place
sponge between nerve and vessel
What is the etiology of afferent pupillary defect in orbital compartment syndrome?
Compression of posterior ciliary arteries which leads to
optic nerve ischemia
What is the description and treatment of keratoacanthoma?
Description
• Nodule with crater like center
• Low-grade tumor that originates in the
pilosebaceous glands
• Closely resembles squamous cell carcinoma
Treatment
• Complete excision
What is the definition of a nevus?
Undifferentiated melanocytes found at the epidermal-dermal border
What is a description of ephelides (freckle)?
• Flat pigmented skin change due to melanocytes
producing too much pigment
• Normal number of melanocyte cells → produce
increased number of melanosomes filled with melanin
Actinic keratosis is what type of lesion and can lead to which type of cancer?
• Premalignant lesion
• Leads to squamous cell cancer
What are common signs of thyroid-associated orbitopathy?
• Eyelid retraction (superior scleral show) in 90%
• Exophthalmos in 60%
• Lid lag in 50%
• Positive Von Graefe sign: eyelid is slow to go down
when patient looks down
What is the etiology, clinical findings, diagnosis, and treatment of “indirect” (dural) carotid-cavernous fistula?
Etiology
• Rupture of thin-walled dural arteries that normally
cross the cavernous sinus → form fistula between
branches of internal or external carotid and cavernous sinus
Clinical findings:
• Chronic red eye → corkscrew conjunctival and
episcleral vessels
• Lack history of trauma
Diagnosis
• Dilated superior ophthalmic vein and inferior
ophthalmic vein
• Enlarged or congested extraocular muscles
Treatment
• Endovascular placement of coils, glue, or occlusive
devices to close the fistula
What is the etiology, clinical findings, and treatment of “direct” carotid-cavernous fistula (CCF)?
Etiology
• Caused by trauma - more common in young males
• Fistula between internal carotid artery (ICA) and
cavernous sinus
Clinical findings
• More fulminant, explosive symptoms compared to
indirect CCF due to high blood flow between ICA and
cavernous sinus
• Very prominent proptosis
• Chemosis
• Ophthalmoplegia
• Orbital pain
• Vision loss
Treatment
• Endovascular placement of coils, glue or occlusive
devices to close the fistula
What is a common presentation and workup of sebaceous carcinoma?
Common presentation
• Recurrent chalazion in the same location
Workup
• Full thickness biopsy of lesion → Oil red O or Sudan
black stain on fresh tissue
• If biopsy positive, then obtain map biopsy of
surrounding conjunctiva
• Sentinel lymph node biopsy after mapping
• Commonly exhibits pagetoid spread
• If the carcinoma spreads from conjunctival epithelium
→ progress very rapidly
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What is the etiology, presentation, and causes of ankyloblepharon?
Etiology
• Normally eyelids are fused together from week 8 to
week 20 of gestation, they separate prior to birth
• In ankyloblepharon, upper and lower eyelids fail to
completely separate
Presentation
• Partial or complete fusion of upper and lower lids by webs of skin
Causes
• Congenital
• Acquired (trauma, inflammation)
What is the definition of epiblepharon?
Pretarsal skin and orbicularis override eyelid margin,
causing eyelashes to be pushed toward ocular surface.
What is the description and associations of euryblepharon?
Description
• Horizontal lengthening of lower eyelid, combined
with vertical shortening of lower eyelid skin → leads
to lateral lower lid being pulled away from ocular surface
Associations
• Blepharophimosis syndrome
• Isolated finding
What vascular structures are 8 mm medial to the medial canthal tendon?
Angular artery and vein
What are common post-op complications of a facelift?
• Post-op hematoma: Occurs first 12 hours after
surgery. Must be drained
• Skin flap necrosis: Risk factors are extensive cautery
to flap, stretching the skin tightly, hematoma
accumulation and poor patient vascularity. This
takes days before frank necrosis is apparent
• Nerve injury: Injury to sensory nerves (branches of
trigeminal). May cause numbness of overlying skin.
Self-limited and rarely painful
• Infections: Rare, occur < 1% of time, typically occur >
3 days after surgery
What are the measurements of various components of the nasolacrimal duct?
• Vertical portion of canaliculi: 2 mm
• Horizontal portion: 8 to 10 mm
• Nasolacrimal sac: 12 to 15 mm; extends 2 to 3 mm
above medial canthal tendon
• Nasolacrimal duct: 12 mm
• Average length from punctum to nose: 35 mm
How much more common is thyroid eye disease (TED) in women compared to men?
● TED 6x more common in women
○ TED in women - 86%
○ TED in men - 14%
● Peak incidence of TED in women follows bimodal
pattern at ages 40-44 years and 60-64 years
● Peak incidence of TED in men is 60-69 years
● Side note: Relative risk of developing TED is 7 times
higher in smokers compared to nonsmokers
Lateral pretarsal eyelid tissues drain into which vein?
Lateral pretarsal eyelid tissues drain into which vein?;
Medial pretarsal eyelid tissues drain into which vein?
Angular vein
Posterior tarsal eyelid tissues drain into which veins?
• Orbital veins
• Deeper branches of anterior facial vein
• Pterygoid plexus
The angular artery is an extension of which artery?
External carotid artery → facial artery → angular artery
What are the branches of the ophthalmic artery?
• Central retinal artery
• Short and long posterior ciliary arteries
• Extraocular muscle arteries
What is the most common pathogen responsible for preseptal cellulitis resulting from trauma and its treatment?
● Staphylococcus aureus
● Treatment
○ Broad spectrum → penicillin or cephalosporin
○ MRSA coverage → clindamycin or
trimethoprim-sulfamethoxazole
What is fibrous dysplasia?
● Benign disorder
● Normal bone is replaced with immature bone
○ Immature bone impinges on vital structures if it
occurs in facial skeleton or orbit
● CT scan shows ground glass bony opacities or
complete sclerosis of bone
What is an osteoma?
● Abnormal growth of normal bone onto other sites
○ Can grow on other bones (homoplastic)
○ Can grow on other tissues (heteroplastic)
What is a sphenoid wing meningioma and its radiologic findings?
• Hyperostosis of bone with sheet-like dural plaque
• CT scan shows hyperostotic bone enhancement with contrast
What is the most common site, type, and method of diagnosis of orbital lymphoma?
Most common site
• Superotemporal, lacrimal gland fossa
Type
• 90% are non-Hodgkin B cell → 40-60% of which are
MALT variety
Diagnosis
• Fresh biopsy not in fixation, enable flow cytometry
What are acute treatments for compressive optic neuropathy from thyroid associated ophthalmopathy?
• High dose steroids (intravenous or oral)
• Urgent orbital decompression
What is Crouzon syndrome?
• Most common type of craniosynostosis
• Autosomal dominant
• Branchial arch syndrome
• Occurs in 1.6 per 100,000
• Premature closure of one or more of metropic,
sagittal, or lambdoidal sutures
• Anatomically shallow orbits results in bilateral
congenital proptosis and midface hypoplasia
• Syndactyly absent
What is the mechanism of action of botulinum toxin?
Prevents release of acetylcholine from presynaptic
neuron from neuromuscular junction.
What is the cellular origin, cause, and association of Kaposi sarcoma?
Cellular origin
• Endothelial cells
Cause
• HHV-8 (human herpes-8) infection in
immunocompromised patients
Association
• AIDS-defining illness
• Mistaken for subconjunctival hemorrhage when they
occur in subconjunctiva
From where does orbital septum arise?
Extension of periosteum.
What is the normal configuration of the lateral canthal tendon insertion in relation to the medial canthal tendon insertion?
Lateral canthal tendon inserts 2 mm more superior than
medial canthal tendon.
What is epicanthus supraciliaris?
Medial eyelid skin fold that is more prominent from eyebrow to lacrimal sac
What is epicanthus tarsalis?
Medial eyelid skin fold that is more prominent in upper eyelid
What is epicanthus inversus?
Medial eyelid skin fold that is more prominent in the
lower eyelid
What is epicanthus palpebralis?
Medial eyelid skin fold that is equally prominent upper
and lower eyelid
What is rhabdomyosarcoma?
● Derived from undifferentiated pluripotent
mesenchymal cells
● FOXO1 gene translocation
● Clinical findings
○ Increased fullness of eyelids
○ Periocular ecchymosis
○ Proptosis
○ Ocular misalignment
○ Typical age of presentation is 8 to 10 years
● Types (“embryonal everyone; pleomorphic please;
alveolar awful)
○ Embryonal (80% cases, most common),
common in supranasal quad, good survival rate
Alveolar, most malignant, common in lower orbit
○ Pleomorphic, best prognosis
● Treatment
○ Radiation, chemotherapy
What conditions are comorbid with myasthenia gravis (MG)?
• Graves disease (5-10% of MG)
• Thymoma (10% of MG)
What is the most common pathogen, workup, and treatment of infectious canaliculitis?
Pathogen
• Actinomyces israelii, filamentous gram positive rods
→ stone formation within canalicular system
Workup
• Culture purulent material manually expressed from
punctum
Treatment
• Warm compresses, lid massages, broad spectrum
topical antibiotics
• If unresponsive or if stone is present →
canaliculotomy from conjunctival side and allow for
healing by second intention. Stones protect
microbes from antibiotics, therefore stones need to
be surgically removed
What are the types, advantages, and disadvantages of non-porous ocular implants?
Types of non-porous ocular implants
• Glass
• Silicone
• Acrylic
Advantages
• Less expensive
• Faster surgery
Disadvantages
• Higher risk of exposure or extrusion
○ Decrease risk of exposure by wrapping the
implant in autogenous or donor sclera, or coat
the implant with absorbable material
What are the types, advantages, and disadvantages of porous ocular implant?
Types of porous ocular implants
• Hydroxyapatite
• Porous polyethylene
• Aluminum oxide
Advantages
• Tiny pores that vascularize with surrounding orbital
soft tissue
• Allow for better implant motility
• Less risk of implant migration
• Lower infection rate
Disadvantages
• High risk of exposure or extrusion through
conjunctiva
What does solar lentigo look like and what is it associated with?
• Seen in older patients
• Sun exposed skin
• Flat, regular pigmentation resembling freckles but
larger in size
What is lentigo maligna and what is it associated with?
• Similar to solar lentigo except irregular pigmentation
• 30-50% of these lesions progress to melanoma
What is lentigo simplex?
• Resembles freckles but larger
• Not related to sun exposure or age
In relation to superficial musculoaponeurotic system (SMAS), what is an appropriate plan for dissection to minimize risk of injury to the facial nerve?
● Stay deep to SMAS in upper face, superficial to SMAS
in lower face
○ In upper face, facial nerve lies superficial to
SMAS
○ In lower face, facial nerve lies deep to SMAS
What is a description of caruncular oncocytoma and its clinical findings?
Description
• Transformed salivary-type epithelial cells with
increased mitochondria
• Benign tumors
• Mimic conjunctival melanoma
Clinical findings
• Pigmented conjunctival lesion
• Smooth cystic appearance
• Slow growth
What are adrenochrome deposits?
• Hyperpigmented spots
• Occur on conjunctiva
• Seen after chronic exposure to topical epinephrine
or its analogues (dipivefrin)
What skin condition characterized by rough “sandpaper” texture with round and scaly appearance can progress to squamous cell cancer?
Actinic keratosis
• Premalignant lesion
• Caused by UV damage
• Most common premalignant skin lesion that
progresses to squamous cell carcinoma occurring in
2% of cases at 4 years
What structures are innervated by the superior branch of cranial nerve 3?
• Superior rectus
• Levator palpebrae
What is the management of indirect traumatic optic neuropathy?
• No good evidence based surgical or medical options available
• Conservative management
What is the most common location and source of sebaceous gland carcinoma?
• Location: Upper eyelid
• Source: meibomian and Zeis glands
What are the Garcia-Harris guidelines?
As a general recommendation, observation with
intravenous antibiotics only is indicated when:
• Under 9 years of age (likely to be culture negative or
no more than one aerobic bacterial species)
• No intracranial involvement
• Medial wall abscess of moderate size
• No vision loss or afferent pupillary defect (no signs
of optic neuropathy)
• No front sinus involvement
• No dental abscess
What structures are located superior to the annulus of Zinn?
“LFTs”
• Lacrimal nerve of cranial nerve V1
• Frontal nerve of cranial nerve V1
• Trochlear cranial nerve IV
• Superior ophthalmic vein
What structures are within the annulus of Zinn?
• Superior and inferior divisions of cranial nerve III
• Nasociliary branch of cranial nerve V1
• Sympathetic roots of ciliary ganglion
• Cranial nerve VI
Which vascular structure is inferior to annulus of Zinn?
Inferior ophthalmic vein
What is the step ladder management approach to congenital nasolacrimal duct obstruction?
Crigler massage, topical antibiotics, and/or observation
↓
Probe and irrigate
↓
Repeat probe +/- inferior turbinate fracture, balloon dacryoplasty, intubating with silicone stents
↓
DCR, if canaliculi are imperforate or obliterated → conjunctivodacryocystorhinostomy (cDCR)
What are the various causes of ectropion?
• Involutional: Most common due to horizontal lid
laxity
• Paralytic: Decreased facial nerve innervation to
orbicularis oculi muscle
• Mechanical: Mass physically weighing down the lid
and pulling it away from globe
• Congenital: Rare, association with blepharophimosis
syndrome and lid defects (i.e. euryblepharon)
• Cicatricial: Tightness of eyelid skin tethers the lid
into everted position. Due to scarring, actinic
damage, autoimmune, or chronic inflammation
What are the anatomical functions of medial canthal tendon?
• The tendon splits into anterior and posterior limb go
around lacrimal sac
• Anterior limb inserts on the anterior lacrimal crest
• Posterior limb inserts on to posterior lacrimal crest
• Anterior portion is responsible for structural support
of eyelid
• Posterior portion is responsible for keeping eyelid
and punctum opposed to globe
What is the distance between the two orbits?
25 mm
What is the location of the widest section of the orbit?
1 cm posterior to anterior orbital rim
What is the most common subtype of periorbital or orbital non-Hodgkin B cell lymphoma and its presentation, diagnosis, and treatment?
Most common
• Mucosa-associated lymphoid tissue (MALT)
lymphomas
• Arise within lacrimal gland, orbit, or eyelid
Presentation
• Indolent
Diagnosis
• Fresh and unpreserved specimens for cell surface
markers and flow cytometry
Treatment
• Orbital radiation
How is the Jones I test performed?
• Assess patency of nasolacrimal drainage system
• Place topical fluorescein into conjunctival fornices
• Then place cotton swab within inferior meatus at 2
and 5 minutes later
• If cotton swab is stained with fluorescein → patent passages
• If cotton swab is not stained with fluorescein →
obstruction is present
How is the Jones II test performed?
• Performed if Jones I test is unsuccessful
• Irrigate lacrimal system with normal saline
• Then collect fluid in nose with swab
• If dye stained saline is retrieved → indicates
functional obstruction of nasolacrimal system
• If unstained saline is retrieved → indicates
mechanical obstruction of nasolacrimal system
What is the appearance of trichofolliculoma?
• Solitary, umbilicated lesion
• Fine blonde hairlike structure at its center or sebum
secreting pore
What is the appearance of trichoepithelioma?
• Flesh-colored papules with overlying telangiectasias
• Commonly confused with basal cell cancer
What is the appearance of pilomatricoma?
Reddish-purple, often calcified subcutaneous mass
attached to overlying skin
In the upper eyelid of Caucasian patients, where does the superior orbital septum fuse with the levator palpebrae superioris in relation to the tarsal plate?
The septum fuses with levator 2 to 5 mm superior to the
tarsal plate
In Asian upper eyelid, where does the superior orbital septum fuse with the levator palpebrae superioris in relation to the tarsal plate?
Between the upper border of the tarsal plate and eyelid margin
Which periocular sites of origin of lymphoproliferative lesions have the highest risk for developing systemic non-Hodgkin’s lymphoma?
● Eyelid lymphoma → 67% develop systemic
lymphoma (highest risk)
● Orbital lymphoma → 35% develop systemic
lymphoma
○ Lesions from lacrimal fossa have higher risk of
systemic disease than those originating
elsewhere in the orbit
● Conjunctival lymphoma → 20% develop systemic
lymphoma
Which lower eyelid structure is analogous to the levator aponeurosis in the upper eyelid and where does this structure originate from?
● Capsulopalpebral fascia
○ Originates from muscle fibers of inferior rectus,
extends forward, wraps around inferior oblique,
then inserts into inferior tarsal border
When would you consider using a frontalis sling in repairing eyelid ptosis?
Levator function 4 mm or less
What is a lipodermoid and what might condition it be associated with?
• Also known as dermolipoma
• Form of congenital choristoma
• Occasionally associated with Goldenhar syndrome
(oculoauriculovertebral dysplasia)
What is the clinical presentation and demographics of conjunctival lymphoma?
Presentation
• Rubbery, salmon-colored subconjunctival mass
• Sculpts around shape of sclera rather than adhering to it
Demographics
• Peak age 40 to 60 years
• Slight female predominance
What is the incidence of uveal melanoma in patients with nevus of ota (oculodermal melanocytosis) versus Caucasian patients without nevus of ota?
Patients with nevus of ota
• Risk of uveal melanoma is 1 in 400
Caucasian patients without nevus of ota
• Risk of uveal melanoma is 1 in 13,000
What is the risk of glaucoma in ocular or oculodermal melanocytosis?
• 10% risk of glaucoma
• Requires scleral involvement
Which structure does the lateral horn of the levator aponeurosis divide?
Divides lacrimal gland into orbital and palpebral lobes
Which ligament changes the direction of force of the levator muscle?
● Whitnall’s ligament
○ Changes direction from anterior-posterior to
superior-inferior
What is Whitnall’s tubercle?
Bony prominence on zygomatic bone on lateral orbital
wall
Which cells are responsible for inflammatory manifestations of thyroid eye disease?
● Orbital fibroblasts
○ Become dysregulated by autoantibodies →
produce glycosaminoglycan → infiltrate
extraocular muscles → induce extraocular
muscle hypertrophy
○ During inactive state of disease → muscles are
atrophic and fibrotic
Which diagnostic test for myasthenia gravis has the least side effects and how is this test conducted?
● Ice pack test
○ Ice pack in placed on closed eyelids for 2 to 5 minutes
○ Ptosis improvement by 2mm or improvement in
strabismus by at least 10 PD → positive test
What structures pass through the inferior orbital fissure?
• Branch of cranial nerve V2 → infraorbital nerve
• Zygomatic nerve
• Inferior ophthalmic vein
• Branches from sphenopalatine ganglion
What are signs and symptoms of floppy eyelid syndrome (FES) and its systemic association?
Signs and symptoms of FES
• Chronic papillary conjunctivitis
• Flaccid upper eyelids
• Nonspecific ocular irritation
FES systemic association
• Up to 96% have some degree of obstructive sleep apnea
Which extraocular muscles do not originate from annulus of Zinn?
• Levator palpebrae superioris → originates from
sphenoid bone
• Superior oblique → originates from sphenoid bone
at the orbital apex, medial to optic canal
• Inferior oblique → originates maxillary bone
Which meatus does the sphenoid sinus drain into?
Sphenoethmoid recess
Which meatus does the posterior ethmoid sinus drain into?
Superior meatus
Which meatus do the maxillary, middle ethmoid, anterior ethmoid, and frontal sinuses drain into?
Middle meatus
Which meatus does the nasolacrimal duct drain into?
Inferior meatus
For blepharoplasty of the upper eyelid, what is a good rule of thumb for the amount of skin to be left behind?
● 20 mm of total skin remaining
○ 10 mm from upper portion of incision to inferior
border of eyebrow. 10 mm from inferior portion
of incision to eyelid margin
What is the type, presentation, and treatment of entropion caused by chlamydia trachomatis?
Type of entropion
• Cicatricial entropion
Presentation
• Scarring and vertical shortening of posterior lamella
results in cicatricial entropion
• Arlt’s line: scarring of upper lid posterior lamella
causing a white line
Treatment
• Oral and topical antibiotic (i.e. PO azithromycin and
topical tetracycline)
• Horizontal tarsal fracture and bilamellar tarsal
rotation procedure to evert the lashes away from cornea
How many meibomian glands are located in upper and lower eyelids?
• Upper eyelid: 25-40
• Lower eyelid: 20-30
What creates the upper eyelid crease?
Levator attachments to orbicularis and skin
What creates the gray line along the eyelid margin and where is it located?
• Muscle of Riolan, also known as pretarsal orbicularis
• Located anterior to tarsal plate
What is Muir-Torre syndrome?
• Genetic syndrome, autosomal dominant
• Combination of sebaceous tumors of skin plus one
or more internal malignancies
• Mutation in mismatch repair genes responsible for
hereditary nonpolyposis colon cancer
• Increased risk of colorectal cancer, endometrial
cancer, stomach cancer, ovarian cancer, urinary tract
cancer, and hepatobiliary cancer
What is Gorlin syndrome (basal cell nevus syndrome or nevoid basal cell carcinoma syndrome)?
• Autosomal dominant
• Develop basal cell carcinoma → typically appearing
in adolescence or early adulthood
• Develop benign jaw tumors (keratocystic
odontogenic tumors)
• Some develop childhood medulloblastoma, cardiac
fibromas, or ovarian fibromas
What is the sign of Leser-Trelat?
• Sudden onset of multiple seborrheic keratoses
• Paraneoplastic finding due to internal organ
malignancy → GI cancer, breast cancer, lung cancer,
urinary tract cancer, and lymphoid tissue cancer
What are the branches of cranial nerve V1?
• Nasociliary
• Frontal
• Lacrimal
What structural abnormality is the most common cause of congenital nasolacrimal duct obstruction?
● Membranous obstruction of valve of Hasner
○ Valve between nasolacrimal duct and inferior meatus
What is a hidrocystoma?
● Cystic lesions derived from sweat glands
● Types
○ Eccrine or apocrine
○ Eccrine hidrocystoma: Benign; cysts filled with
clear fluid
○ Apocrine hidrocystoma: Benign; cysts filled with
milky fluid
● Increase in size with heat and humidity
● Treatment
○ Complete excision of cyst lining
What is a xanthelasma?
Description
• Yellow discolored skin plaque
Pathology
• Infiltration with foam cells → lipid filled
macrophages within dermis
Common location
• Medial canthal skin
Associations
• Hyperlipidemia
Treatment:
• Observation
• YAG or CO2 laser
• Topical trichloroacetic acid
• Excision
What is the definition and treatment of Bowen’s disease?
Definition
• In-situ squamous cell cancer of skin
Treatment
• Surgical excision or topical 5-FU
Which bony structure separates the superior orbital fissure from the optic canal?
Optic (sphenoid) strut
What are the signs and symptoms of the fibrous reaction seen in metastatic breast cancer to the orbit?
• Enophthalmos or proptosis
• Restricted motility because tumor may elicit fibrous
response in the orbit
• Pain
• Chemosis
Which orbital wall has the shortest anterior-posterior length?
● Orbital floor
○ Does not extend into the orbital apex unlike the
other orbital walls
○ Ends at the pterygopalatine fossa
Which vasculature is between Muller’s muscle and the levator palpebrae superioris just superior to the tarsal plate?
Peripheral arterial arcade
What is the location of the marginal arterial arcade?
2 mm superior to cilia and anterior to the tarsal plate
What is the most common cause of acquired ptosis?
Aponeurotic
What are the clinical findings in congenital ptosis?
• Fibrofatty dysgenesis of levator muscle → weaker
and stiffer eyelid
• Lid crease is attenuated or absent
• Ptosis in primary gaze
• Retracted in downgaze
What are the causes of acquired nasolacrimal duct obstruction?
• Prior dacryocystitis
• Midfacial trauma involving bony nasolacrimal duct
• Sinusitis
• Stenosis due to medical treatment (i.e. radioactive
iodine for thyroid ablation in Graves or docetaxel for
breast cancer)
• Manipulation during previous probe and irrigation
• Malignancy (i.e. squamous cell cancer)
What is an indication for conjunctivodacryocystorhinostom y (cDCR) and how it this procedure performed?
Indication
• Obliterated canaliculi (trauma or surgical resection
due to neoplasm)
Procedure
• External cDCR opening is made through caruncle →
tract is created through the bone directly into
middle meatus → straight posterior inferomedial
trajectory
• Rigid hollow tube is placed through the tract to
maintain patency, otherwise 100% tendency for this
pathway to obstruct
How is the procedure dacryocystorhinostomy performed?
• Uses patient’s puncta and canaliculi but bypasses
nasolacrimal duct
• After surgery, tears flow through punta into
canaliculi, then through surgically opened lacrimal
sac and osteotomy into middle meatus
Which foramen does cranial nerve V1 pass through?
Superior orbital fissure
Which foramen does cranial nerve V2 pass through?
Foramen rotundum
Which foramen does cranial nerve V3 travel through?
Foramen ovale
What percentage of patients with thyroid associated ophthalmopathy (TAO) will be in hyperthyroid state at some point?
● 90% have Graves and will have hyperthyroidism at some point
○ Among hyperthyroid patients, only 30% develop TAO
Which types of thyroid conditions are seen with thyroid associated ophthalmopathy (TAO)?
• 90% hyperthyroidism
• 6% euthyroid
• 3% Hashimoto’s
• 1% primary hypothyroidism
What are the thinnest bones of the orbit?
• Lamina papyracea (part of ethmoid bone)
• Maxillary bone
What is the strongest wall of the orbit?
Lateral wall made up of zygomatic and greater wing of sphenoid
Which lobe of the lacrimal gland can be biopsied?
Orbital lobe (avoid palpebral lobe)
What is the most common primary orbital malignancy of childhood and its presentation?
• Rhabdomyosarcoma
• Proptosis and spontaneous periorbital ecchymosis
What is Merkel cell carcinoma of the eyelid?
• Neuroendocrine derived malignancy
• Violaceous red color and well-circumscribed fusiform shape
• 5-year survival rate is 50%
What are the complications of injecting corticosteroids subcutaneously into an eyelid?
• Skin depigmentation
• Elevation of intraocular pressure
• Central retinal artery occlusion
What two orbital pathologies involve the sphenoid bone?
● Sphenoid dysplasia in NF1 resulting in pulsatile
proptosis of globe
● Sphenoid wing meningioma
○ Expansion of bony volume → proptosis,
compressive optic neuropathy
○ 20% of cranial meningioma involve sphenoid wing
How soon should you place a conformer back in the eye in case it falls out after enucleation or evisceration?
● Conformer should not be removed for > 24 hours
○ If left out for several days → fornices can
adhere to each other
○ If a conformer is not placed back in → it will be
difficult to place a prosthetic in the future,
requiring mucous membrane grafting to
reconstruct fornices
What is a junctional nevus?
• Nests of nevus contained within epidermis
• Along the rete ridges at the base of epidermis near
its junction with dermis
• High malignancy potential
What is an intradermal nevus?
• Nests of nevus contained within dermis
• Low malignant potential
What is a compound nevus?
Nests of nevus cells spanning across dermis and
epidermis
What is an epidermal inclusion cyst?
• Benign
• Ectoderm-derived
• Cysts are lined with squamous epithelium and filled
with keratin that is produced by cyst lining
What is a Le Fort I fracture?
Low transverse maxillary fracture above teeth without
orbital involvement
What is a LeFort II fracture?
Fractures of bilateral nasal, lacrimal, maxillary bones and
medial orbital floor
What is a LeFort III fracture?
Fracture at the craniofacial disjunction in which entire
facial skeleton is detached from the base of skull
What is the indication for lateral tarsal strip procedure and how is it performed?
Indication
• Correction of involutional ectropion
Procedure
• Shortening of the lower eyelid and then suturing it
to the periosteum
• Maintains a sharp lateral canthal angle
What is the indication for medial spindle procedure and how is it performed?
Indication
• Correction of medial ectropion or punctal ectropion
Procedure
• Removing diamond shaped piece of conjunctiva and
lower lid retractors 4 mm inferior to inferior
canaliculus → then placing inverting sutures
What is the indication for Cutler Beard procedure and how is it performed?
Indication
• Correction of upper eyelid defect that is > 50% of
eyelid width
Procedure
• A full-thickness lower eyelid flap is moved into the
defect of the upper eyelid by advancing the flap
behind the remaining lower eyelid margin
What is the indication of the modified Hughes procedure and how is it performed?
Indication
• Correction of lower eyelid defects >50% of eyelid width
Procedure
• Advancement of a tarsoconjunctival flap from the
upper eyelid into the posterior lamellar defect of the
lower eyelid
What is the indication for direct closure of an eyelid defect?
Eyelid defects that are <33% of eyelid width
How do you repair eyelid defects which are 33-50% of eyelid width?
Eyelid is freed with lateral canthotomy and semicircular
flap (Tenzel flap) is rotated into the defect
What is the most common metastatic orbital tumor in children? What is its presentation, workup, and treatment?
● Metastatic orbital neuroblastoma
● Presentation
○ Proptosis
○ Spontaneous eyelid ecchymosis (raccoon eyes)
○ Horner’s syndrome
○ Opsoclonus (sometimes)
● Work up
○ Urinary catecholamines
○ Imaging of neck, chest, and abdomen
● Treatment
○ Chemotherapy
What is the definition and types of Marcus Gunn Jaw Winking?
Definition
• Aberrant innervation connection (synkinesis)
between muscles of (pterygoid) and levator muscle
Types
• Lateral (external) pterygoid synkinesis: most
common; connection between external pterygoid
and levator muscle. Eyelid opens with jaw opening,
movement of jaw to contralateral side or forward
movement of jaw
• Medial (internal) pterygoid synkinesis: less common;
connection between internal pterygoid and levator
muscle. Eyelid opens with jaw closure
What is Whitnall’s tubercle and what attaches to it?
Definition
• Bony prominence on zygomatic bone that 10mm
inferior to the frontozygomatic suture, just posterior
to lateral orbital rim
Tubercle attachments
ALL (“L”s)
• Lockwood’s ligament
• Lateral rectus check ligament
• Lateral horn of levator
• Lateral canthal tendon
Side note: Whitnall’s ligament does not attach here,
rather forms fibrous attachments to lateral wall near
lacrimal gland, 10 mm superior to Whitnall’s tubercle
What is the medical term for acute infection of meibomian gland orifices?
Internal hordeolum
What is the medical term for acute infection of Zeis glands?
External hordeolum
What is the definition of chalazion?
• Chronic, sterile, lipogranulomatous inflammation of
oil glands within the eyelid
• Glands involved: meibomian glands, zeis glands
Where is the temporal artery located?
Within superficial layers of temporoparietal fascia
What are some examples of septate fungi?
• Fusari
• Aspergillus
• Curvularia
What are some examples of non-septate fungus?
• Mucor
• Rhizopus
What is the most common cause of nasolacrimal duct obstruction in adults?
Involutional stenosis from either infectious or
autoimmune process
What is the definition and most common cause of a dacryolith?
Definition
• Stone within canaliculus
Most common cause
• Actinomyces israelii: anaerobic gram positive
filamentous
What is an indication for Quickert sutures?
Indication
• Temporary fix of entropion while waiting for more
definitive intervention such as a lateral tarsal strip
procedure
What is the definition and treatment of spastic entropion?
Definition
• Contraction of orbicularis → rolls eyelid margin
inward → then relaxation of muscle → eyelid to reposition
Treatment
• Botox injection to weaken orbicularis contraction
• May require surgery → orbicularis debulking +/-
lateral tarsal strip +/- retractor reinsertion
What are the differential diagnosis for chronic dacryoadenitis?
• Sarcoidosis
• Thyroid eye disease
• Orbital inflammatory syndrome
• TB
What are the causes, origin, and presentation on imaging of optic nerve sheath meningioma?
Causes
• Occur in isolation
• Association with neurofibromatosis-2
Origin
• Arise from nerve sheath meninges and form dense
mass encasing optic nerve
Presentation on imaging
• “Tram track” sign
• Sheath tumor appears as two parallel lines
resembling railroad tracks flanking optic nerve
What are the various types of and risk factors for basal cell cancers (BCC)?
Types
● Nodular: Most common type. Firm, raised, pearly
nodule and “peripheral palisading”
○ Ulcerative: Center of nodular BCC breaks down
into an open ulcer
● Pigmented: Rare, hyperpigmented and resembles
nodular
● Sclerosing: Morpheaform, infiltrating BCC; flat,
depressed, shiny and scar-like plaque
Risk factors
• Sun exposure
• Fair skin
• Immunosuppression
• Gorlin syndrome
• Xeroderma pigmentosum
What are ways to remove basal cell cancer?
• Mohs procedure: Preferred approach. Enables
tighter margin and layer-by-layer margin surveillance
• Complete excision: Done with 3 mm margins
Which periorbital location of basal cell cancer has the highest risk of orbital expansion?
Medial canthal lesions
What are ways to potentiate lidocaine injection and their mechanisms of action?
• Hyaluronidase: Disperses lidocaine to a greater
degree
• Epinephrine: Constricts blood vessels → prevents
elimination of lidocaine and increases its time of
action
• Sodium bicarbonate: Buffers solution and decreases
pain on injection
What are the most common types of melanoma around the eyelid?
• Lentigo maligna melanoma: 90% of melanomas
occurring on head and neck
• Nodular melanoma: Second most common, 10% of
melanomas occurring on head and neck
What is the definition and causes of distichiasis?
Definition
• Growth of eyelashes from abnormal site
Causes
• Severe blepharitis
• Ocular cicatricial pemphigoid
• Stevens Johnson syndrome
• Chemical or thermal burns
What is the definition and causes of trichiasis?
Definition
• Lashes from normal location but misdirected
Causes
• Any cause of entropion
• Prostaglandins
What are the types of holocrine glands and their mechanism of action?
Types
• Meibomian glands
• Zeis glands
Mechanism of action
• Material that is made in the cytoplasm of these
glands’ cells is released into lumen of the gland
ducts by disruption of cellular membrane (cell is
destroyed when its contents are released)
What is an example and mechanism of action of apocrine glands?
Type
• Glands of Moll
Mechanism of action
• Secrete via merocrine mechanism
• Portion of cytoplasm containing the product is
pinched off and expressed into a glandular duct →
“decapitation secretion”
What is the most common type, presentation, incidence, and treatment of primary malignancy of lacrimal sac?
Most common type of primary lacrimal sac malignancy
• Squamous cell carcinoma
Presentation
• Mass above medial canthal tendon
• Bloody tears
• Epiphora
• Regional lymphadenopathy
Incidence
• 45% lacrimal sac tumors are benign; 55% are
malignant
Treatment
• Dacryocystectomy followed by radiation.
• Exenteration is sometimes necessary if there is
orbital invasion
Which meatus is directly adjacent to the lacrimal sac fossa?
Middle meatus
What is the life cycle of a nevus from early-in-life to old age?
Junctional
↓
Compound
↓
Intradermal
What structure connects the recti muscles and forms a boundary between intraconal and extraconal space?
Intermuscular septum
What are the insertion distances in spiral of Tillaux?
Medial rectus: 5.5mm
Inferior rectus: 6.5mm
Lateral rectus: 6.9mm
Superior rectus: 7.7mm
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What are the risk factors for severe thyroid eye disease?
• Smoking
• Male (although women are 6x more likely to develop
thyroid associated ophthalmopathy)
• Pretibial myxedema
• Radioactive iodine
What is the most common etiology for congenital blepharoptosis?
Myogenic → abnormal development of levator muscle
What are causes of axial displacement?
• Cavernous hemangioma
• Arteriovenous malformation
• Optic nerve sheath meningioma
• Optic nerve glioma
• Orbital metastases
• Other intraconal tumors
What are causes of non-axial displacement?
● Lacrimal gland tumors
○ Push globe inferomedially
● Frontoethmoidal masses (tumors or mucoceles)
○ Located in the superomedial orbit
○ Push globe inferotemporally
● Maxillary sinus tumors
○ Push globe superiorly
Sarcoidosis has greatest the affinity for which structures in head and neck?
Lacrimal gland and parotid gland
What are clinical findings and associations in Heerfordt syndrome (uveoparotid fever)?
Clinical findings
• Uveitis
• Facial palsy
• Fever
Associations
• Sarcoidosis
• Lyme disease
• TB
• Syphilis
What are clinical findings in Lofgren syndrome and what is it associated with?
Clinical findings
• Bilateral hilar adenopathy
• Arthropathy
• Fever
• Erythema nodosum
Association
• Sarcoidosis
What are clinical findings in Mikulicz syndrome and what is it associated with?
Clinical findings
• Xerostomia (dry mouth)
• Parotid gland enlargement
• With or without lacrimal gland enlargement
• Dry eye
Associations
• Sarcoidosis
• Lymphoma
• Sjogrens
• TB
What is von Hippel Lindau disease?
• Autosomal dominant
• Mutation of VHL tumor suppressor gene,
chromosome 3
• Multisystem tumor formation
• Associated with retinal hemangiomas,
hemangioblastomas, and pheochromocytomas
• Usually develop in third decade of life or later
What is the etiology of congenital ectropion and what is it associated with?
Etiology
• Due to shortening of anterior lamella of eyelid
• Most are mild and respond to conservative
measures like lubrication
Associations
• Blepharophimosis syndrome
• Downs syndrome
• Ichthyosis
• Ectodermal dysplasia
What is the appearance of molluscum lesions?
Waxy, nodular lesions with central umbilication
What is the differential diagnosis for a “salmon pink” subconjunctival lesion and its origin?
Differential diagnosis
• Reactive lymphoid hyperplasia (benign)
• Conjunctival lymphoma (malignant)
Origin
• Lymphoid origin
What is the mechanism of action and indication to use topical imiquimod?
Mechanism of action
• Stimulates cytokine release including
interferon-alpha and TNF-alpha
Indication
• Cutaneous melanoma in situ and basal cell
carcinoma
What are the definitions of telecanthus, hypertelorism, and exorbitism?
• Telecanthus: greater than normal distance between
medial canthi
• Hypertelorism: excessive distance between medial
orbital walls
• Exorbitism: prominent eyes due to shallow orbits or
increased angle of divergence of orbital walls
What are the most common antibodies found in thyroid disease?
• Thyroid microsomal antibodies
• Antibodies to thyroglobulin
What is Meige syndrome?
Definition
• Essential blepharospasm with facial grimacing
• Can progress from benign essential blepharospasm
• Unknown etiology
Workup
• CT/MRI to rule out posterior fossa lesions
Treatment
• Local: Botox
• Systemic: Tetrabenazine, lithium, carbidopa, or
clonazepam
What are the differences and similarities between hemifacial spasm and benign essential blepharospasm (BEP)?
Hemifacial spasms
• Persist during sleep
• Unilateral
• Spasms mostly due to vascular compression of cranial
nerve 7 in the brain stem
• MRI to evaluate for ectatic vessel and rule out
cerebellopontine lesion
BEP
• Bilateral focal dystonia with increased blinking and
involuntary spasms or periocular protractor muscles
• Stops during sleep
• Can progress to Meige syndrome with lower facial
dystonia
• Dysfunction of basal ganglia
Treatment in hemifacial spasms and BEP
• Botox in both conditions
What are the associations with craniosynostosis syndrome?
• Strabismus
• Astigmatism
• Ptosis
• Exophthalmos
• Nasolacrimal duct obstruction
• Amblyopia
What is the order of surgical therapy for thyroid eye disease?
Orbital decompression
↓
Strabismus surgery
↓
Eyelid retraction repair
↓
Blepharoplasty
What are the types of eyelid ptosis and their findings?
• Aponeurotic: Levator attenuation or disinsertion resulting in
superior migration of orbital septum and preaponeurotic fat.
Seen with elderly patients, long-standing hard contact lens
use, good levator function, thin eyelid skin, high lid crease and
deep superior sulcus. Associated with post trauma,
long-standing edema and chronic allergies with eye-rubbing
• Congenital: Absent or poorly formed eyelid eyelid crease.
Associated with poor levator function
• Neurogenic: Associated with Horner syndrome and cranial
nerve 3 palsy
• Myogenic: Seen with muscular dystrophy, chronic progressive
external ophthalmoplegia, myasthenia gravis and
oculopharyngeal dystrophy
• Mechanical: Weighing or pulling down on upper eyelid. Seen
with plexiform neurofibroma, hemangioma, acquired
neoplasm, large chalazion, skin carcinoma, temporarily due to
post surgical and post traumatic edema
What are the types of craniosynostosis and their unique findings?
• Crouzon syndrome (most common): syndactyly is absent
• Apert syndrome: syndactyly present
• Treacher Collins syndrome: mandibulofacial
dysostosis and underdeveloped lower jaw
• Goldenhar syndrome (oculoauriculovertebral
syndrome): ear, nose, soft palate, lip and mandible
deformities, limbal dermoids, and strabismus
What is the definition of nanophthalmos and what is it associated with?
Definition
• Axial length 15 to 20 mm
Associations
• Normal or slightly enlarged lens
• Thick sclera
• Predisposed to uveal effusion and glaucoma
What is pleomorphic adenoma (benign mixed tumor)?
• Most common epithelial lacrimal gland tumor
• Slow growth → gradual proptosis without pain
• Excavating lacrimal fossa
• Stimulates new bone growth without erosion
• Recurrences occur with incomplete excision or seeding of orbit from
incisional biopsies; difficult to manage
• Treatment: complete removal with adequate margin, violation of
pseudocapsule and leaving remnants behind increases recurrence.
• Pathology (see below): combination of epithelial and stromal lacrimal
gland elements
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What are the various forms of epicanthus?
• Epicanthus tarsalis: fold most prominent along
upper eyelid
• Epicanthus inversus: fold most prominent along
lower eyelid
• Epicanthus palpebralis: fold involves both upper and
lower eyelids
• Epicanthus superciliaris: fold originates from brow
and goes down to lacrimal sac
Which chemotherapy agents cause inflammation and scarring of canaliculi?
• Docetaxel
• 5FU
• Idoxuridine
• Eserine
• Phospholine iodine
What are the differences between facial myokymia and hemifacial spasm?
Facial myokymia
• Continuous unilateral contraction of facial muscle
bundles
• Intramedullary disease of pons at cranial nerve 7
nucleus or fascicle
• Result of pontine glioma or demyelination
Hemifacial spasm
• Unilateral episodic spasms involving facial
musculature
• Most commonly due to compression of cranial nerve
7 root exit zone by aberrant vessel
What are the associated findings in thyroid eye disease?
• Spares extraocular muscle tendons
• Eyelid retraction - most common ophthalmic feature
(>90%)
• Exophthalmos (60%)
• Restrictive extraocular myopathy (40%)
• Optic nerve dysfunction (5%)
• Diplopia (17%)
• Pretrial myxedema (4%)
• Myasthenia gravis (<1%)
What is the presentation and cause of crocodile tears?
Presentation
● Lacrimation while chewing
Cause
● Aberrant facial nerve regeneration
● Due to severe injury to proximal cranial nerve 7
What is the depth of the orbit in an adult?
40 to 45 mm from the orbital entrance to the orbital apex
