Plastics Flashcards
What drains into inferior meatus? Middle meatus? Superior meatus? Sphenoethmoidal recess?
Inferior meatus: nasolacrimal duct
Middle meatus: maxillary sinus, anterior and middle ethmoid sinuses, frontal sinus
Superior meatus: posterior ethmoid sinus
Sphenoethmoidal recess: sphenoid sinus
Differential for orbital mass with bony destruction in children
Malignancy: primary rhabdomyosarcoma, metastatic neuroblastoma, granulocytic sarcoma (rapidly progressive inflammation)
Histiocytic disorders, e.g. Langerhans cell histiocytosis (recurrent relapsing episodes of inflammation as opposed to rapidly progressive)
What treatment is contraindicated in patients with orbital masses causing bony destruction?
Corticosteroids
2 most common sites for orbital metastasis
Extraocular muscles (abundant vascular supply)
Bone marrow space of the sphenoid bone second most common (high volume of low-flow blood)
Biopsy of the ___ lobe of the lacrimal gland should be avoided because of potential damage to the ___ ___.
Biopsy of the palpebral lobe of the lacrimal gland should be avoided because of potential damage to the lacrimal duct.
Histology of mucormycosis
Nonseptate, large branching hyphae
Why can zygomycoses like Mucor cause vascular occlusions?
Fungi have propensity for invading blood vessel walls, causing thrombosing vasculitis
What is the most common cause of proptosis in a child? What are some other differentials? (3)
Orbital cellulitis
Orbital rhabdomyosarcoma
Intraorbital foreign body
Idiopathic orbital inflammation
Where do the marginal and peripheral arcades of the upper eyelid, and the arterial arcade of the lower eyelid, come from?
Anastomosis between the ICA (to ophthalmic artery to supraorbital and lacrimal artery) and ECA (to angular and temporal artery) circulations
Where is the marginal arcade found?
2 mm superior to the eyelid margin just anterior to the tarsus
Where is the peripheral arcade found?
Superior to the tarsus, between the levator aponeurosis and the Müller muscle
Where is the arterial arcade found?
Just inferior to the tarsus in the lower eyelid
How does repair of cicatricial ENtropion differ from that for cicatricial ECtropion?
Cicatricial entropion: posterior lamella must be augmented with a mucous membrane graft (buccal or amniotic)
Cicatricial ectropion: anterior lamella requires a skin graft
The anterior and posterior origins of the medial canthal tendon fuse just temporal to the ___ ___. The anterior limb inserts on the anterior lacrimal crest, the posterior limb on the posterior crest.
The anterior and posterior origins of the medial canthal tendon fuse just temporal to the lacrimal sac. The anterior limb inserts on the anterior lacrimal crest, the posterior limb on the posterior crest.
The lacrimal gland is not fully functional until the infant is about __ weeks old. Thus, newborn infants do not produce tears when crying.
The lacrimal gland is not fully functional until the infant is about 6 weeks old. Thus, newborn infants do not produce tears when crying.
What are the most common pathogens in orbital cellulitis affecting neonates? Older children and adults? Older or immunosuppressed patients?
Neonate: S aureus and gram-negative bacilli
Older children and adults: S aureus, Strep pyogenes, Strep pneumoniae
Older or immunosuppressed: polymicrobial, including gram-negative and anaerobic organisms
What abnormality are chemotherapeutic agents such as docetaxel (or 5-fluorouracil) associated with?
Canalicular obstruction (consider prophylactic intubation, otherwise may require CDCR)
Differential for slowly progressive, superomedial (above the medial canthal tendon) orbital mass in a child? Adult?
Child: expanding skull base process, e.g. encephalocele (inferior herniation of brain tissue), meningocele (herniation of the meninges), meningoencephalocele (herniation of both) common in congenital clefting syndromes, dermoid cysts
Adult: meningocele, mucocele, lacrimal sac malignancy
5 tumors of mesenchymal origin
- Solitary fibrous tumors (e.g., hemangiopericytoma, fibrous histiocytoma)
- Rhabdomyosarcomas
- Fibrous histiocytoma
- Osteomas
- Fibrous dysplasia
A botulinum toxin injection into the ___ muscle would improve horizontal rhytids in the inferior glabellar area.
A botulinum toxin injection into the procerus muscle would improve horizontal rhytids in the inferior glabellar area.
Treatment of the ___ ___ muscles affects the more vertically oriented rhytids.
Treatment of the corrugator supercilii muscles affects the more vertically oriented rhytids (causes glabellar folds).
Treatment of the ___ muscle would improve horizontal/transverse forehead rhytids.
Treatment of the frontalis muscle would improve horizontal/transverse forehead rhytids.
Injection into the ___ ___ muscle is typically in the lateral crow’s feet” region.
Injection into the orbicularis oculi muscle is typically in the lateral crow’s feet” region.
On CT, fibrous dysplasia characteristically has a ___ appearance on imaging with sparing of the ___ ___.
On CT, fibrous dysplasia characteristically has a ground-glass appearance on imaging with sparing of the soft tissues.
Give examples of solitary fibrous tumors (2). How are these managed?
Hemangiopericytoma, fibrous histiocytoma
Complete surgical excision (metastatic potential)
___ is a cause of necrotizing fasciitis in diabetic patients; however, necrotic tissue in the oropharynx is more consistent with ___.
(Group A beta-hemolytic) Streptococcus is a cause of necrotizing fasciitis in diabetic patients; however, necrotic tissue in the oropharynx is more consistent with Mucor.
TED is associated with hyperthyroidism in __% of patients, but __% may be euthyroid.
TED is associated with hyperthyroidism in 90% of patients, but 6% may be euthyroid.
The ___ space is the most peripheral surgical space in the orbit and is closest to the sinuses.
The subperiosteal space is the most peripheral surgical space in the orbit and is closest to the sinuses.
Symblepharon can be treated with conjunctival ___. If severe, a full-thickness ___, ___, or ___ ___ graft may be required.
Symblepharon can be treated with conjunctival Z-plasty. If severe, a full-thickness conjunctival, buccal, or amniotic membrane graft may be required.
What structures must you avoid damaging when operating in the medial orbit? (3 complexes)
- Medial canthal tendon, lacrimal canaliculi and sac
- Trochlea, superior oblique tendon and muscle
- Inferior oblique muscle
Also have sensory nerves and vessels along the medial aspect of the superior orbital rim
The presence of an optic neuropathy and ___ ___ ___ point to decreased perfusion to the globe and optic nerve and require emergency intervention.
The presence of an optic neuropathy and retinal arterial pulsations point to decreased perfusion to the globe and optic nerve (orbital compartment syndrome!) and require emergency intervention -> canthotomy/cantholysis.
Most common tumors of the lacrimal sac (2)
Squamous cell papillomas and carcinomas
Embryonal rhabdomyosarcoma has a predilection for the ___ quadrant of the orbit.
Embryonal rhabdomyosarcoma has a predilection for the superonasal quadrant of the orbit.
In the temporal area, the temporal (frontal) branch of cranial nerve VII crosses the ___ ___ and courses superomedially in the deep layers of the ___ ___ (also called the ___ ___ ___), often near branches of the temporal artery.
In the temporal area, the temporal (frontal) branch of cranial nerve VII crosses the zygomatic arch and courses superomedially in the deep layers of the temporoparietal fascia (also called the superficial temporalis fascia), often near branches of the temporal artery.
A Hughes flap is a ___ flap from the ___ lid used to reconstruct the ___ lamella, often after surgery for skin cancer.
A Hughes flap is a tarsoconjunctival flap from the upper lid used to reconstruct the posterior lamella, often after surgery for skin cancer.
A free tarsal graft augments the ___ lamella.
A free tarsal graft augments the posterior lamella.
With an ___ lamellar deficiency, the skin and muscle needs to be augmented, preferably with a ___ ___ graft.
With an anterior lamellar deficiency, the skin and muscle needs to be augmented, preferably with a full-thickness skin graft.
The restrictive strabismus of thyroid eye disease most often causes ___ and ___ from involvement of the ___ and ___ recti muscles, respectively.
The restrictive strabismus of thyroid eye disease most often causes hypotropia and esotropia from involvement of the inferior and medial recti muscles, respectively.
Management of congenital nasolacrimal fistulas if asymptomatic? If signs of infection?
Asymptomatic: observation
If infection: systemic antibiotics, and complete excision of the fistula, with or without stenting of the normal lacrimal drainage system to maintain its patency
Surgery for thyroid eye disease should be delayed until the disease reaches a stable state for at least __ to __ months.
Surgery for thyroid eye disease should be delayed until the disease reaches a stable state for at least 6 to 9 months.
A Le Fort I fracture is a ___ fracture of the ___ just above the teeth and has no orbital involvement.
A Le Fort I fracture is a transverse fracture of the maxilla just above the teeth and has no orbital involvement.
A Le Fort II fracture involves the midface. It typically involves the ___ and may extend to the ___ ___ ___, resulting in posttraumatic ___.
A Le Fort II fracture involves the midface. It typically involves the maxilla and may extend to the lacrimal drainage system, resulting in posttraumatic epiphora.
A Le Fort III fracture extends across both orbits and the ___ ___, involving the ___ bone. Le Fort III fractures may involve the ___ ___ and result in traumatic ___ ___.
A Le Fort III fracture extends across both orbits and the skull base, involving the sphenoid bone. Le Fort III fractures may involve the optic canals and result in traumatic optic neuropathy.
(Most easily described as complete craniofacial disjunction, where the face is fractured away from its attachments to the skull)
Naso-orbital ethmoidal or nasoethmoidal complex involve the bones in the area of the ___ ___ ___ and ___ ___. They may result in ___, medial canthal ___, and ___.
Naso-orbital ethmoidal or nasoethmoidal complex involve the bones in the area of the medial canthal tendon and lacrimal sac. They may result in telecanthus, medial canthal rounding, and epiphora.
May also see CSF leakage
A zygomaticomaxillary complex fracture, also known as a tripod or cheekbone fracture, involves the horizontal and vertical buttresses of the ___ and ___. The ___ and ___ orbital rims are usually involved, and an ___ ___ fracture is an associated finding.
A zygomaticomaxillary complex fracture, also known as a tripod or cheekbone fracture, involves the horizontal and vertical buttresses of the maxilla and zygoma. The inferior and lateral orbital rims are usually involved, and an orbital floor fracture is an associated finding.
May also cause trismus (lockjaw) due to impingement on muscles of mastication
In what direction is the globe most likely to be displaced when a child with a congenital orbital cleft cries?
Inferolaterally (congenital clefts through which intracranial contents can herniate into orbit, e.g. meningocele or encephalocele, usually near medial canthus or over bridge of nose)
Typical time course for a capillary hemangioma of the eyelid
Rapid growth in the first 6-12 months of life, subsequent period of regression and involution, complete regression around 5 years of age
Lower eyelid retractor ___, lower eyelid ___, and overriding ___ ___ muscle are characteristics of involutional entropion.
Lower eyelid retractor disinsertion, lower eyelid laxity, and overriding preseptal orbicularis muscle are characteristics of involutional entropion.
Microphthalmia with orbital cyst results from failure of the ___ ___ to close in the embryo.
Microphthalmia with orbital cyst results from failure of the choroidal fissure to close in the embryo.
Craniofacial clefts occur as a result of a failure of ___ ___ cell migration and a failure of ___ of facial processes.
Craniofacial clefts occur as a result of a failure of neural crest cell migration and a failure of fusion of facial processes.
Anophthalmia occurs when the ___ ___ ___ fails to grow out from the cerebral vesicle.
Anophthalmia occurs when the primary optic vesicle fails to grow out from the cerebral vesicle.
Most likely nerve damaged during an inferomedial orbitotomy to explore the intraconal space?
CN III
Considerations for exenteration (6)
(1) intraocular melanoma or retinoblastoma that has extended outside the globe in the absence of distant metastases
(2) destructive tumors extending into the orbit from the sinuses, face, eyelids, conjunctiva, or intracranial space
(3) malignant epithelial tumors of the lacrimal gland
(4) fungal infections
(5) sarcomas
(6) other primary orbital malignancies that do not respond to nonsurgical therapy
The ___ branch of CN VII innervates the corrugator supercilii.
The temporal (frontal) branch of CN VII innervates the corrugator supercilii.
How do you differentiate fibrous dysplasia from meningiomas?
Lack of dural enhancement in fibrous dysplasia on MRI
What is the pathogenesis of silent sinus syndrome? How does it present?
Silent sinus syndrome is marked by chronic subclinical sinusitis that can lead to thinning and collapse of the orbital floor.
Presents with enophthalmos, relative retraction of the ipsilateral upper eyelid, transient diplopia after a recent significant change in atmospheric pressure, such as airplane travel, high-altitude climbing, or scuba diving.
The long branches of the posterior ciliary artery supply the ___ ___, the ___, and ___.
The long branches of the posterior ciliary artery supply the ciliary body, the iris, and eyelid.
What is Bowen disease? How is it managed?
SCC in situ of the skin; complete surgical excision (otherwise progresses to vertically invasive squamous cell carcinoma)
Treatment of rhabdomyosarcoma
Orbital radiation and systemic chemotherapy
Differential for concurrent scleritis and nasal inflammation (3)
cANCA-associated vasculitis, relapsing polychondritis, syphilis
Best orbitotomy approach for intraconal tumor between lateral rectus and optic nerve? Superior lesion? Medial orbital lesions? (2)
Lateral intraconal tumor: lateral orbitotomy, with or without a bone flap
Superior: vertical lid-splitting orbitotomy
Medial orbit: transcaruncular and medial orbitotomy
Management of adenoid cystic carcinoma
Incisional biopsy
Complete excision can require exenteration and radical orbitectomy with removal of the roof, lateral wall, and floor along with the overlying soft tissues. There is no evidence that this disfiguring approach or other aggressive treatment such as radiation, chemotherapy, or a combination of these modalities improves prognosis.
Patients with orbital fractures are instructed not to blow their nose for __ weeks following the injury.
Patients with orbital fractures are instructed not to blow their nose for 2 weeks following the injury.
Management of dacryocystitis associated with lacrimal sac abscess
I&D followed by oral antibiotics
How does inferior rectus muscle contusion/edema following trauma present?
Hypertropia worsening on downgaze with gradual improvement after onset
Findings for lacrimal gland lymphoma versus pleomorphic adenoma on orbital ultrasound
Low internal reflectivity indicating that the lesion is homogeneous = lymphoma
Medium-high internal reflectivity = pleomorphic adenoma (also may contain cysts)
Most common malignant tumor derived from the paranasal sinuses?
Squamous cell carcinoma
To avoid excessive skin removal during an upper lid blepharoplasty, a minimum of how much remaining skin is typically left between the inferior border of the brow and the upper eyelid margin?
20 mm
Options for repair of a large full-thickness eyelid defect (>60%) (3)
Requires reconstruction of the mucosa-lined posterior lamella and the cutaneous anterior lamella, so at least one of the lamellae should be a vascularized flap; free grafts of both lamellae will not survive.
(1) Hughes flap (upper tarsoconj flap) + skin grafting of anterior lamella
(2) Free tarsoconjunctival graft from the contralateral upper eyelid with vascular supply from a pedicled skin–muscle flap (NOTE: pedicled NOT rotational -> only for moderate-sized defects)
(3) Cutler-Beard: full-thickness lower eyelid flap
Management of subperiosteal abscess may consist of careful observation unless any of the following criteria are present (9)
(1) Patient aged 9 years or older
(2) Presence of frontal sinusitis
(3) Non-medial SPA location
(4) Large SPA
(5) Suspicion of anaerobic infection (eg, presence of gas in abscess on CT)
(6) Recurrence after prior drainage
(7) Evidence of chronic sinusitis (eg, nasal polyps)
(8) Acute optic nerve or retinal compromise
(9) Infection of dental origin (anaerobic infection more likely)
Treatment of blepharospasm patients who are poorly responsive to botulinum therapy and incapacitated by the spasms
Surgical myectomy of orbital and palpebral orbicularis in upper and sometimes lower eyelids (permanent)
Repair of lower lid cicatricial entropion with retraction
Posterior lamellar shortening -> lengthen with hard-palate spacer graft or other autologous or alloplastic graft
Repair of typical involutional ectropion? Tarsal ectropion?
Typical: horizontal tightening with lateral tarsal strip
If tarsal ectropion (retractor laxity, disinsertion, or dehiscence): advancement and reattachment of the lower lid retractors provides more vertical stability
A mass above the medical canthal tendon associated with ___ ___ is concerning for an orbital roof fracture.
A mass above the medial canthal tendon associated with pulsating exophthalmos is concerning for an orbital roof fracture.
What prophylactic treatment is frequently used to prevent scarring after laser skin resurfacing?
Oral antivirals (HSV outbreaks can lead to significant scarring)
Clinical presentation and management of aberrant lacrimal ductules
Found several mm lateral and superior to the eyelash line and can mimic epiphora. Usually accompanied by a tuft of eyelashes.
Treat by simple excision
Management of hypoplastic orbits
socket expansion with conformers, followed by augmentation with dermis-fat grafts
Associations of fibrous dysplasia? (2)
(1) Albright syndrome: fibrous dysplasia with cutaneous pigmentation and endocrine disorders
(2) NF2
Distinguish between blepharospasm and hemifacial spasm (2)
Blepharospasm: bilateral involvement of protractors, abates at night, can progress to Meige syndrome
Hemifacial spasm: unilateral symptoms that persist at night
What brow lift procedure is performed through upper eyelid blepharoplasty incision? Through incisions at upper edge of brow hairs? Through small incisions 1cm behind hairline? Through incision below hairline?
Upper eyelid blepharoplasty incision: Browpexy (good for mild cases)
Upper edge of brow hairs: Direct brow elevation (good for predominantly lateral brow ptosis)
1cm behind hairline: Endoscopic brow and forehead lift (good for short forehead)
Below hairline: Pretrichial brow and forehead lift (good for large forehead)
The bulbar conjunctiva is supplied by the ___ ___ ___, which arise from muscular branches of the ___ ___.
The bulbar conjunctiva is supplied by the anterior ciliary arteries, which arise from muscular branches of the ophthalmic artery.
The blood flow to the upper eyelid is provided by the ___ ___ ___ and the ___ ___.
The blood flow to the upper eyelid is provided by the marginal arterial arcade and the peripheral arcade.
The ___ ___ supplies the temporal aspect of the scalp.
The temporal artery supplies the temporal aspect of the scalp.
Blepharophimosis inheritance pattern and mutation
Autosomal dominant mutation of FOXL2 gene on chromosome 3
Lower eyelid retractor reattachment is most appropriate for correction of what condition?
Involutional entropion without significant horizontal laxity
3 principal mechanisms behind involutional entropion
1) horizontal laxity of the eyelid (lateral tarsal strip)
2) disinsertion or atrophy of the lower lid retractor complex (reinsertion of retractor)
3) overriding preseptal orbicularis oculi muscle (partial myectomy)
What surgical step during nano-orbital ethmoid fracture repair is critical to prevent poor apposition of medial eyelid to globe postoperatively?
Posterior attachment of medial canthal tendon to posterior lacrimal crest
Fibrous dysplasia inheritance pattern
Sporadic
Management of patient with left hypertropia worsening on downgaze associated with limitation of infraduction of the left eye following orbital floor fracture
Observation with monocular occlusion (likely inferior rectus muscle contusion/edema. Entrapment would cause right hypertropia worsening on upgaze, due to limited supraduction of left eye)
Most superior structure traveling through annulus of Zinn
Optic nerve
Medial orbital wall landmark corresponding to level of cribriform plate
Ethmoidal foramina
The periorbita is firmly attached to the ___ ___ anteriorly and the ___ ___ covering the optic nerve at the apex.
The periorbita is firmly attached to the arcus marginalis anteriorly and the dura mater covering the optic nerve at the apex.
(Otherwise loosely attached to underlying bone -> allows for potential subperiosteal space for pus or blood to collect)
For the best result, the ___ ___ ___ requires surgical suspension.
For the best result, the suborbicularis oculi fat requires surgical suspension.
What fat pad is traversed when performing a browpexy?
Retro-orbicularis (suspended to frontal periosteum to elevate brow internally)
A fracture of what structure defines a Le Fort fracture?
Pterygoid plates (part of sphenoid bone)
Note: All Le Fort structures involve maxilla, but not all maxillary fractures are Le Fort fractures
Ophthalmic conditions associated with craniosynostoses (7)
- Proptosis
- Corneal exposure
- Exophthalmos
- Ptosis
- Strabismus
- Astigmatism
- NLDO
Management of biopsy-confirmed malignant melanoma
Wide surgical excision with evaluation of margins by permanent sections
Preferred surgical approach for:
- suspected lacrimal gland tumor
- inferior orbital masses
- medial intraconal space
- superomedial intraconal tumors
- medial wall fracture/orbital bone decompression/subperiosteal abscess
Suspected lacrimal gland tumor: Eyelid crease incision or extended lateral canthotomy incision
Inferior orbital masses: Swinging lower eyelid approach
Medial intraconal space: Eyelid crease or transconjunctival incision
Superomedial intraconal tumors: Vertical full-thickness splitting of upper eyelid with transconjunctival exposure
Medial wall fracture/orbital bone decompression/subperiosteal abscess: Retrocaruncular incision
What is the significance of the arcus marginalis?
Periosteum reflects here to become orbital septum (and forms subperiosteal space)
In the upper eyelid, the orbital septum fuses with the ___ ___ 2 mm to 5 mm above the superior tarsal border in non-Asians. In the lower eyelid, the orbital septum fuses with the ___ ___ at or just below the inferior tarsal border.
In the upper eyelid, the orbital septum fuses with the levator aponeurosis 2 mm to 5 mm above the superior tarsal border in non-Asians. In the lower eyelid, the orbital septum fuses with the capsulopalpebral fascia at or just below the inferior tarsal border.
Uses of the argon laser? CO2 laser? Erbium:YAG laser?
Argon laser is commonly used to ablate the lash follicle to prevent the lash from returning.
The CO2 laser is typically used for resurfacing or to create a skin incision.
The erbium:YAG laser is used for skin resurfacing.
Treatment of microphthalmia
Socket expansion with progressively larger conformers shortly after birth, with dermis-fat grafts for further expansion of orbital volume if needed, followed by prosthesis fitting
Contraindications for laser resurfacing (4)
- Isotretinoin use in the past 12 months (re-epithelialization is compromised)
- Unrealistic patient expectations
- History of collagen vascular disease (eg, systemic lupus erythematosus)
- Significant residual lower eyelid skin laxity
**Also use caution in hyper pigmented individuals
When operating in the temporal fossa, the temporal/frontal branch of CN VII is found in the ___ ___.
When operating in the temporal fossa, the temporal/frontal branch of CN VII is found in the temporoparietal fascia (AKA superficial temporalis fascia, or SMAS).
Facial nerve branches ___ to the zygomatic arch are ___ to the superficial musculoaponeurotic system.
Facial nerve branches inferior to the zygomatic arch are deep to the superficial musculoaponeurotic system.
(Superior to the arch -> superficial to SMAS)
What is blepharochalasis?
Familial variant of angioneurotic edema; results in drooping upper eyelid skin associated with recurrent swelling
Presentation, work-up and treatment of orbital Langerhans cell histiocytosis
Lytic defect affecting superotemporal orbit or sphenoid wing with relapsing episodes of orbital inflammation
Confirm with surgical biopsy with debulking
Treat with intralesional steroid injection or low-dose radiation if only orbital involvement, chemotherapy if systemic disease. NO oral corticosteroids due to lytic bone lesions.
Contraindication for facial rhytidectomy
Antiplatelet therapy
Muscles involved in myectomy for facial dystonia
Eyelid protractors, e.g. orbicularis oculi
Presentation and management of superficial spreading melanoma
Large flat eyelid lesion with irregular borders and varied pigmentation; total surgical excision with margin evaluation
What conditions are associated with a “soft” stop during lacrimal probing? (2)
Lacrimal tumor or canalicular obstruction
Inheritance of neurofibromatosis 2
Autosomal dominant (but over 50% of cases result from de novo mutations!)
