Flashcards in BCSC Plastics Deck (238):
Are capillary hemangiomas in children benign or malignant?
Benign, but may cause mass effect
When do capillary hemangiomas usually present?
birth to first few weeks of life, enlarging over first 6-12 months
What percent of capillary hemangiomas resolve within the first 4-5 years of life?
Is CVS a risk factor for capillary hemangioma?
How can MRI be used to distinguish capillary hemangiomas from other vascular malformations?
MRI will show fine vascular channels and high blood flow
What part of the orbit do capillary hemangiomas have a propensity for?
What are the major complications of capillary hemangiomas?
Amblyopia, strabismus, and anisometropia
What are possible treatments for capillary hemangiomas?
topical or systemic beta blockers, steroids, surgical excision
What is the most common benign neoplasm of the orbit in adults?
What is the histology of the cavernous hemangioma?
The lesions are encapsulated and composed of large cavernous spaces containing RBCs. The walls contain smooth muscle
Are arteriography and venography useful in evaluation of cavernous hemangiomas?
No, there is little communication with the systemic circulation
What is the management of cavernous hemangioma?
Surgical excision after imaging if there is compromise of ocular function
Are hemangioperictyomas common?
What is the histology of the hemangiopericytoma?
Plump pericytes surround a rich capillary network
When do lymphatic malformations (lymphangiomas) generally present?
Within the first decade of life in the orbit
What is the histology of the lymphatic malformation?
They generally contain both lymphatic and venous components and are characterized by large, serum-filled channels that are lined by flat endothelial cells
Are lymphatic malformations technically neoplasms?
No, because their endothelial cells do not proliferate
What are the features of lymphatic malformations on MRI?
multiple grape-like cystic lesions with fluid-fluid layering of the serum and red blood cells
How can a venous malformation be diagnosed?
With demonstration of engorgement on spiral CT during a Valsalva maneuver (decreasing venous return)
What is the management oforbital venous malformations?
Conservative, with surgical excision only if there is vision-threatening compressive optic neuropathy; embolization with coils may also be employed
What are arteriovenous fistulas?
acquired lesions caused by abnormal direct communication between an artery and a vein
What are the possible causes of an AV fistula?
Trauma or degeneration
What are the 2 forms of AV fistula?
Carotid cavernous fistula (typically occurs after a basal skull fracture) and Spontaneous Dural Cavernous Fistula (degenerative process in older pts with HTN and atherosclerosis)
Do carotid cavernous fistulas have high blood flow?
What are findings associated with carotid cavernous fistula?
Tortuous epibulbar vessels, audible bruit, pulsatile proptosis
How does a carotid cavernous fistula cause damage?
Bypass of the capillary network results in ocular ischemia; Direct passage of blood into the venous system results in venous outflow obstruction --> increased IOP, choroidal effusions, blood in Schlemm canal, nongranulomatous iritis, increased cavernous sinus pressure leading to CN III, IV, and VI palsies
How do Dural Cavernous Fistulas occur?
small meningeal arterial branches communicate with venous drainage
How does chronic red eye occur in Dural Cavernous Fistula?
Arterialization of the conjunctival vessels
How is embolization of AV fistulas usually accomplished?
endovascular transarterial route
What are the types of neural tumors of the orbit?
optic nerve gliomas, neurofibromas, meningiomas, and schwannomas
Are optic nerve gliomas benign or malignant?
They are benign in the first decade of life, but can be malignant if onset is in the adult male
What is the prognosis for malignant optic nerve gliomas?
Very poor -- usually death within 6-12 months even with treatment
What percent of optic nerve gliomas are associated with neurofibromatosis?
What are the clinical findings of optic nerve glioma?
gradual, painless, unilateral axial proptosis associated with loss of vision and an afferent pupillary defect
What is the gross pathology of the optic nerve glioma?
Smooth, fusiform intradural lesion
Where do optic nerve gliomas in patients with NF usually proliferate?
the subarachnoid space
What are the findings of optic nerve glioma on CT or MRI?
fusiform enlargement of the optic nerve with sterotypical kinking of the nerve
What are the possible treatment options for optic nerve glioma?
Observation only, surgical excision, radiation therapy, radiation therapy
Of what are neurofibromas composed?
proliferating Schwann cells within nerve sheaths with occasional axons, endoneural fibroblasts, and mucin
What are the two types of neurofibromas?
PlexiformNeurofibromas and Discrete Neurofibromas
Which type of neurofibroma (plexiform or discrete) is easier to excise surgically?
In which form of neurofibromatosis do plexiform neurofibromas usually occur?
What is the inheritance of NF 1?
autosomal dominant with incomplete penetrance
What are the clinical findings in NF 1?
Plexiform neurofibromas of the lateral aspect of the upper eyelid (S-shaped contour of lid), pulsating proptosis, optic nerve glioma
What are meningiomas?
Invasive tumors arising from the arachnoid villi
What are the findings of meningioma on neuroimaging?
diffuse tubular enlgargement of the optic nerve with contrast enhancement. On CT, calcification may be seen within the meningioma referred to as tram-tracking
What is the most common primary orbital malignancy of childhood?
What is the average age of onset of rhabdomyosarcoma?
What is the common clinical picture of rhabdomyosarcoma?
child with sudden onset, rapidly-progressive unilateral proptosis with discoloration of the eyelids; ptosis and strabismus may also be present
From what do rhabdomyosarcomas arise?
Undifferentiated pluripotential mesenchymal elements of the orbital soft tissues (not from the extraocular muscles)
What are the 4 categories of rhabdomyosarcoma?
Embryonal, Alveolar, Pleomorphic, Botryoid
What is the common management of rhabdomyosarcoma?
Biopsy via anterior orbitotomy, surgical excision if there is a pseudocapsule, chemo and radiation, possible exenteration
What is the most common form of rhabdomyosarcoma?
Which form of rhabdomyosarcoma has the worst prognosis?
Alveolar, 10-year survival rate 10%
Which form of rhabdomyosarcoma has the best prognosis?
Pleomorphic, 97% survival rate
What portion of orbital tumors are lymphoproliferative neoplasms?
What is the most common type of orbital lymphoproliferative disease?
Malignant non-Hodgkin B-cell lymphoma
What percent of orbital lymphomas are MALT lesions?
What percent of patients with orbital MALT will develop systemic disease at 10 years?
What is the classic clinical presentation of a lymphoproliferative lesion?
Gradually progressive painless mass
What is the classic clinical appearance of a lymphoproliferative lesion?
Salmon patch underneath the conjunctiva or located anteriorly in the orbit
What type of biopsy is preferred for lymphoproliferative lesions?
What percent of orbital lymphoproliferative lesions have on diagnosis or will have associated systemic disease within 5 years?
What is the treatment of choice for localized orbital lymphoproliferative lesions?
Radiation, with a dose of 2000 to 3000 cGy
What is the most common presentation of Langerhans cell hystiocytosis in the orbit?
A lytic lesion of the superotemporal orbit with associated orbital inflammation (which may be confused initially for infectious orbital cellulitis)
What are the 4 types of adult xanthogranuloma of the orbit (in order of frequency)?
1) Necrobiotic xanthogranuloma (NBX), 2) Adult-onset asthma with periocular xanthogranuloma (AAPOX), 3) Erdheim-Chester disease (ECD), 4) Adult-onset xanthogranuloma (AOX)
What do most lacrimal gland masses represent?
Non-specific inflammation of the lacrimal gland (dacryoadenitis)
What is a common dichotomy of lacrimal gland tumors?
Epithelial origin vs. non-epithelial origin
What is the most common epithelial tumor of the lacrimal gland?
The pleomorphic adenoma (benign mixed tumor)
What is the common clinical presentation of a pleomorphic adenoma of the lacrimal gland?
Patient in the 4th or 5th decade of life presenting with slowly progressive, painless downward displacement of the globe with axial proptosis
Should a suspected pleomorphic adenoma of the lacrimal gland be biopsied?
No, it should be completely excised surgically maintaining an intact pseudocapsule
What is the most common malignant tumor of the lacrimal gland?
The adenoid cystic carcinoma (cylindroma)
What percent of patients with orbital neuroblastoma survive?
90% if diagnosed before age 1, 10% if diagnosed after age 1
What is the most common type of leukemia to metastasize to the orbit?
Acute lymphoblastic leukemia
What are the two most common metastases to the orbit?
Breast and lung tumors
What is the most common orbital metastasis in women?
What is the most common orbital metastasis in men?
What part of the face do Le Fort fractures involve?
What is a Le Fort I fracture?
a low transverse maxillary fracture above the teeth with no orbital involvement
What is a Le Fort II fracture?
a pyramidal fracture involving the nasal, lacrimal, and maxillary bones, as well as the medial orbital floor
What is a Le Fort III fracture?
craniofacial disjunction with involvement of the orbital floor and medial and lateral orbital walls
What is craniofacial disjunction?
A condition in which the entire facial skeleton is completely detached from the base of the skull and suspended only by soft tissues
What are the sites of fracture in a tripod fracture of the zygomaticomaxillary complex (ZMC)?
the lateral orbital rim, inferior orbital rim, zygomatic arch, lateral wall of the maxillary sinus
Are orbital roof fractures more common in adults or children?
Children. Since the frontal bone has not pneumatized yet in children, frontal trauma is more likely to extend to the orbital roof in children, whereas in adults, the frontal sinus acts as a crumple zone and dissipates energy of frontal impacts
What is another name for a direct medial orbital fracture?
A naso-orbital-ethmoidal fracture
What are the common clinical characteristics of a nas-orbital-themoidal fracture?
Depressed bridge fo the nose and traumatic telecanthus
What is an indirect medial orbital fracture?
A fracture of the medial orbit resulting from a blowout fracture of the orbital floor
What are the common physicial sings of an orbital floor fracture?
Eyelid edema and ecchymosis; diplopia with limitation of upgaze, downgaze, or both; enophthalmos and ptosis of the globe; hypoesthesia in the distribution of the infraorbital nerve; orbital and eyelid emphysema
What is an exception to initial observation of an orbital floor fracture?
Inferior rectus trapping beneath a trapdoor fracture (IR in maxillary sinus on CT) in pediatric patients
In which situations is surgery advisable in the case of an orbital floor fracture?
1) Diplopia with limitation of upgaze and/or downgaze within 30 degrees of primary position with positive forced ductions 7-10 days after injury and with radiologic confirmation; 2) Enophthalmos that exceeds 2mm and is cosmetically unacceptable to the patient; 3) Large fractures involving at least half of the orbital floor, particularly when associated with large medial wall fractures (determined by CT)
Can MRI be safely performed with a BB in the orbit?
Should BBs be removed from the orbit when found?
Usually, they are best left in place
What are the 5 surgical spaces within the orbit?
1) subperiorbital (subperiosteal) space (a potential space); 2) extraconal space (outside the muscle cone, between the cone and the periorbita); 3) episcleral (sub-Tenon) space (between Tenon capsule and globe); 4) intraconal space (inside muscle cone); 5) subarachnoid space (between optic nerve and nerve sheath)
Which type of orbitotomy incision provides the best cosmetic result when attempting to access the supraorbital rim?
An upper eyelid crease incision (rather than an incision directly over the superior orbital rim)
What approach is now usually used to perform an orbital decompression?
Transconjunctival incision with lateral cnatholysis to disinsert and evert the lower eyelid for exposure of the inferior and lateral orbital rims. This incision can be extended superonasally with a transcaruncular approach to access the medial orbital wall for bone removal and decompression
If used in orbital surgery, how long is a drain generally kept in place
no more than 24-36 hours
Should visual acuity be checked frequently after orbital surgery?
Yes, especially in the first 12 hours after surgery
Should patching of the operative site be performed after orbital surgery?
No, since this can delay diagnosis of postoperative hermorrhage
In which situations is enucleation the anophthalmic surgery of choice?
If the nature of intraocular pathology is unknown or if ocular tumor is suspected
What is a benefit of enucleation over evisceration?
Lower likelihood of sympathetic ophthalmia, particularly with severely traumatized eyes
Which are the ocular tumors that most commonly require enucleation?
Retinoblastoma and choroidal melanoma
What are common indications for enucleation?
1) intraocular malignancy not amenable to alternative modes of therapy such as external-beam radiation or episcleral plaque brachytherapy; 2) blind eyes with opaque media and no known cause of ocular disease; 3) blind painful eyes; 4) severely traumatized eyes without hope for visual recovery
What surgical approaches can be used for obtaining exposure for enucleation?
lateral canthotomy or superomedial approach
What are the components of an acceptable enucleation?
1) orbital implant of sufficient volume; 2) socket lined with conjunctiva or other mucous membrane; 3) eyelids with normal appearance and adequate tone; 4) good transmission of motility from implant to prosthesis; 5) comfortable ocular prosthesis that looks similar to the normal eye
What is the value of a dermis-fat graft for an enucleation performed in a child?
The dermis-fat graft grows in children providing necessary pressure to promote orbital growth
What are the advantages of evisceration?
1) less disruption of orbital anatomy; 2) good prosthesis motility (EOMs remain attached to sclera); 3) preferred treatment in some cases of endophthalmitis; 4) technically simpler than enucleation; 5) lower rates of migration, extrusion, and reoperation than enucleation
What are the disadvantages of evisceration when compared to enucleation?
1) not indicated if ocular tumor suspected or in patients with severe pthisis; 2) theoretically increased risk of sympathetic ophthalmia; 3) provides less complete pathologic specimen than does enucleation
What are the functions of an orbital implant?
1) replace lost orbital volume; 2) maintain structure of the orbit; 3) impart motility to the overlying ocular prosthesis
What are the different classes of spherical orbital implants?
Inert (glass, silicone, MMA) and Biointegrated (hydroxyapatite, porous polyethylene)
What are possible locations for orbital implants?
Within the Tenon capsule or behind the posterior Tenon capsule in the muscle cone
When is an ocular prosthesis usually fitted after anophthalmic surgery?
What are common complications of anophthalmic surgery?
1) deep superior sulcus due to decreased orbital volume; 2) contracture of fornices; 3) exposure and extrusion of the implant; 4) contracted socket; 5) anophthalmic ectropion; 6) anophthalmic ptosis; 7) lash margin entropion
What are circumstances in which exenteration may be appropriate?
1) destructive tumors extending into the orbit; 2) intraocular melanomas or retinoblastomas extending outside the globe but without distant metastases; 3) malignant epithelial tumors of the lacrimal gland; 4) sarcomas not responding to nonsurgical therapy; 5) fungal infection (orbital zygomycosis)
What are the types of orbital exenteration?
Subtotal, Total, and Extended
What are the 5 structural planes of the face?
1) Skin; 2) Subcutaneous tissue; 3) Superficial musculoaponeurotic system (SMAS) and mimetic muscles; 4) deep facial fascia; 5) plane containing the facial nerve, parotid duct, and buccal fat pad
How are the mimetic muscles divided?
Upper face and lower face (superficial and deep)
Which muscles animate the forehead and glabella?
frontalis, corrugator, and procerus
Which muscle depresses the eyebrows and closes the eyelids?
Which muscle elevates the eyebrows?
Which muscles are the superficial mimetic muscles?
platysma, zygomaticus major, zygomaticus minor, risorius
Which muscles are the deep mimetic muscles?
buccinator, mentalis, levator anguli oris
What are the 5 major branches of the facial nerve (CN VII)?
Temporal, zygomatic, buccal, marginal mandibular, cervical
What are the 7 structural layers of the eyelids?
1) skin and subcutaneous tissue; 2) muscles of protraction; 3) orbital septum; 4) orbital fat; 5) muscles of retraction; 6) tarsus; 7) conjunctiva
What defines the upper eyelid crease?
The attachments of the levator aponeurosis to the pretarsal orbicularis bundles and skin
What defines the upper eyelid fold?
the loose preseptal skin and sucutaneous tissues above the confluence of the levator aponeurosis and orbital septum
What are the divisions of the orbicularis oculi muscle?
Orbital, pre-septal, and pre-tarsal
Which divisions of the orbicularis oculi muscle are involved in involuntary movement of the eyelids?
Pre-septal and pre-tarsal
Where does the orbital septum fuse with the levator aponeurosis in the upper eyelid?
2-5 mm above the superior tarsal border in non-Asians
Where does the orbital septum fuse with the capsulopalpebral fascia in the lower eyelid?
At or below the inferior tarsal border
What conditions can lead to anterior herniation of the orbital fat in the aging eyelid?
Thinning of the orbital septum and laxity of the orbicularis
How many orbital fat pockets are there in the upper and lower lids, respectively?
2 in the upper lid and 3 in the lower lid.
Where does the orbital fat lie in the upper and lower lids?
posterior to the orbital septum and anterior to the levator aponeurosis (upper lid) or the capsulopalpebral fascia (lower lid)
What are the retractors of the upper lid?
Levator muscle (with levator aponeurosis) and superior tarsal muscle (Muller muscle)
What are the retractors of the lower lid?
Capsulopalpebral fascia and inferior tarsal muscle
Where is the peripheral arterial arcade found?
between the levator aponeurosis and the Muller muscle, just above the superior tarsal border
How tall are the superior and inferior tarsal plates?
10-12mm (superior) and 4mm (inferior)
How are the tarsal plates connected to the periosteum of the orbit?
Via the medial and lateral canthal tendons
Where is the mucocutaneous junction of the eyelid located?
Just posterior to the meibomian gland orifices on the eyelid margin
When do most congenital anomalies of the eyelids occur?
During the second month of gestation
What are the components of Blepharophimosis Syndrome?
Blepharophimosis, telecanthus, epicanthus inversus, severe ptosis.
What are the common associations of congenital ectropion?
Blepharophimosis syndrome, Down syndrome, and icthyosis
What is euryblepharon?
From the Greek eurus, meaning "wide" -- unilateral or bilateral horizontal widening of the palpebral fissure, sometimes associated with blepharophimosis syndrome
What is ankyloblepharon?
From the Greek prefix ankyl, meaning "stiff, unmovable, adhesion" -- partial or complete fusion of the eyelids by webs of skin
What is epicanthus?
a medial canthal fold that may result from immature midfacial bones or a fold of skin and subcutaneous tissue
What are the 4 types of epicanthus?
tarsalis (upper eyelid), inversus (lower eyelid), palpebralis (equal between upper and lower eyelids), supraciliaris (arising from the eybrow region running to the lacrimal sac
What is epiblepharon?
A condition in which the lower eyelid pretarsal muscle and skin ride above the lower eyelid margin to forma horizontal fold of tissue, causing the lashes to assume a vertical position.
What is congenital distichiasis?
A rare, sometimes hereditary condition in which an extra row of lashes is present in place of meibomian gland orifices
Which skin is usually used for grafting eyelid defects?
Contralateral eyelid or pre-auricular or post-auricular skin
Should hair-bearing skin grafts be used around the eye?
No, they should be avoided if possible
Which is preferred in eyelid reconstruction -- full-thickness or split-thickness grafts?
Full-thickness grafts. Split-thickness grafts should be used only when adequate full-thickness skin is not available
Under what condition can direct closure of an upper eyelid defect be performed?
<= 33% of the eyelid margin is involved.
What procedure can be performed in a patient in whom extensive sacrifice of the canaliculi has occrred in the resection of a tumor?
A conjunctivodacryocystorhinostomy with a Jones tube can be performed, but only after an observed recurrence-free period often lasting up to 5 years.
How many days prior to elective periocular surgery is warfarin generally stopped?
2-5 days, if approved by PCP
How many days prior to elective periocular surgery is aspirin generally stopped?
5 days, if approved by PCP
How many days prior to elective periocular surgery are NSAIDs generally stopped?
3 days, if approved by PCP
What are the five classes of ectropion?
1) congenital; 2) involutional; 3) paralytic; 4) cicatricial; 5) mechanical
What is the most common cause of ectropion?
Involutional ectropion (which is itself most often due to horizontal eyelid laxity either in the medial or lateral canthal tendons)
Does involutional ectropion usually affect the upper or lower lid?
What are the 3 most commonly used surgical procedures in treating involutional ectropion?
Medial spindle procedure, Tarsal strip proceudre, and Reinsertion of the lower eyelid retractors
What are the steps in surgically treating cicatricial ectropion of the lower eyelid?
1) surgical release of vertical cicatricial traction; 2) horizontal tightening with a lateral tarsal strip operation; 3) vertical lengthening of the anterior lamella via a midface lift or full-thickness skin graft
What are the 4 types of entropion?
1) congenital; 2) acute spastic; 3) involutional; 4) cicatricial
What is the most common situtation in which acute spastic entropion develops?
Postoperative development due to ocular irritation and inflammation sustained during intraocular surgery in a patient with unrecognized or mild involutional eyelid changes
How is horizontal laxity of the eyelid detected?
1) Poor eyelid tone (snapback test) or 2) ability to pull the eyelid more than 6mm from the globe (distraction test)
What are the clinical signs that may indicate disinsertion of the eyelid retractors?
1) a white subconj line several millimeters below the inferior tarsal border caused by the leading edge of the detached retractors; 2) deeper than normal inferior fornix; 3) lower eyelid margin sitting higher than normal; 4) little or no inferior movement of the lower eyelid on downgaze (limited lower lid excursion)
What are the three types of procedures for repair of involutional entropion?
1) Temporizing measures, 2) Horizontal tightening procedures, 3) repair of the retractors
What are common temporizing measures for repair of involutional entropion?
Quickert sutures and thermal cautery
What are the three etiologic factors in involutional entropion?
1) disinsertion of the eyelid retractors, 2) overriding orbicularis, 3) horizontal laxity
How quickly can trichiasis recur after mechanical epilation?
What are the therapies available for trichiasis?
Mechanical epilation, electrolysis, radiofrequency ablation, cryotherapy, argon laser, full-thickness pentagonal resection with primary closure
What are the five etiologic variants of ptosis (blepharotosis)?
1) myogenic, 2) aponeurotic, 3) neurogenic, 4) mechanical, 5) traumatic
What is the most common etiology of congenital ptosis?
poorly developed levator muscle (myogenic cause)
What is the most common etiology of acquired ptosis?
stretching or disinsertion of the levator aponeurosis (aponeurotic cause)
What are the 5 clinical measurements used to evaluate ptosis?
1) margin-reflex distance, 2) vertical interpalpebral fissure height, 3) upper eyelid crease position (distance from UL crease to UL margin), 4) levator function (upper eyelid excursion), 5) presence of lagophthalmos
What is MRD1?
the distance from the upper eyelid margin to the corneal light reflex in primary position (may be zero or negative)
What is MRD2?
the distance from the corneal light reflex to the lower eyelid margin
What does the sum of MRD1 and MRD2 represent?
The vertical interpalpebral fissure height
How is levator function measured?
By fixating the brow to eliminate frontalis contributions and measuring the distance moved by the upper eyelid margin from downgaze to upgaze (ULE or upper lide excursion)
What are conditions in which synkinesis of the lid and EOM or jaw occurs?
Marcus Gunn jaw-wink, aberrant regeneration of CN III or CN VII, certain forms of Duane sydnrome
Does ptosis tend to improve or worsen in downgaze when congenital?
Congenital ptosis improves in downgaze, unlike acquired ptosis, which worsens.
Is the crease in the typical Asian eyelid higher or lower than in the typical Caucasian eyelid?
What percent of patients with congenital ptosis develop amblyopia?
What congenital conditions involve both EOM dysfunction and ptosis?
1) combined superior rectus/levator muscle maldevelopment; 2) congenital oculomotor palsy
What acquired conditions involve both EOM dysfunction and ptosis?
1) ocular or systemic myasthenia gravis; 2) Chronic progressive external ophthalmoplegia (CPEO); 3) oculopharyngeal dystrophy; 4) oculomotor palsy with or without aberrant regeneration
What conditions involve both ptosis and pupillary abnormalities?
1) Horner syndrome, 2) CN III palsy
How is functional visual impairment assessed in patients with ptosis?
Visual field testing with the eyelids untaped (natural state) and taped (approximating post-surgical state)
What is the most common etiology of congenital myogenic ptosis?
dysgenesis of the levator muscle
What are common causes of acquired or late-onset myogenic ptosis?
muscular dystrophy, chronic progressive external ophthalmoplegia, oculopharyngeal dystrophy
What is the most common form of ptosis?
Acquired aponeurotic ptosis
What is the mechanism of aponeurotic ptosis?
stretching or dehiscence of the levator aponeurosis or disinsertion from its normal position
Is the upper eyelid crease usually higher or lower than normal in acquired aponeurotic ptosis?
What are the causes of congenital neurogenic ptosis?
Congenital CN III palsy, congenital Horner syndrome, Marcus-Gunn jaw-winking syndrome
What is the cause of ptosis in Horner syndrome?
an innervational deficit to the sympathetically innervated Muller muscle (an eyelid elevator second in importance to the levator)
What is the analog of the Muller muscle in the lower lid?
The inferior tarsal muscle
What effect does Horner syndrome have on the inferior tarsal muscle?
since the inferior tarsal muscle, like the Muller muscle, has sympathetic innervation, decreased retraction of the lower lid occurs, resulting in a higher than normal lower lid (sometimes called a lower eyelid reverse ptosis)
What are the two common causes of acquired oculomotor nerve palsies?
1) Ischemic (can be self-limited, especially if pupil-sparing) and 2) Compressive
What percent of myasthenia gravis patients have thymomas?
10%, thus warranting consideration of chest CT scanning at time of diagnosis
What are the tests available for myasthenia gravis?
1) edrophonium test; 2) ice-pack test (which exploits inhibition of acetylcholinesterase at low temperatures); 3) sleep/rest test; 4) acetylcholine receptor antiody test
What are the common medical treatments for myasthenia gravis?
acetylcholinesterase inhibitors and steroids
What surgical intervention is sometimes performed for myasthenia gravis after medical treatments are attempted?
What is dermatochalasis?
a condition in which excess upper eyelid skin overhangs the eyelid margin, transects the pupil, and gives the appearance of a true ptosis of the eyelid margin
What are the 3 categories of surgical procedures commonly used in ptosis repair?
1) External (transcutaneous) levator advancement; 2) internal (transconjunctival) levator/tarsus/Muller muscle resection approaches; 3) frontalis muscle suspensions
What are the most common causes of eyelid retraction?
1) Thyroid eye disease, 2) recession of the vertical rectus muscles, 3) overly aggressive skin excision in blepharoplasty, 4) overcompensation for a contralateral ptosis
What histological changes are seen in the eyelid retractors in TED?
inflammatory infiltration and fibrotic contraction of the sympathetically innervated retractors (Muller muscle and inferior tarsal muscle)
What is the most common cause of paralytic ectropion?
CN VII paralysis or palsy
What is the most commonly performed procedure for treatment of paralytic lagophthalmos?
gold weight loading of the upper eyelid
Is neuroimaging indicated in the workup of blepharospasm?
What are the clinical features of Benign Essential Blepharospasm?
increased blinking, involuntary spasm of the eyelid protractor muscles; may progress to intermittent episodes of inability to open the eyelids
What is the treatment of choice for Benign Essential Blepharospasm (BEB)?
repeated periodic injection of botulinum toxin A
What are the kinetics of botulinum toxin A injections?
Onset: 2-3 days, Peak effect: 7-10 days, Duration of action: 3-4 months
Is the onset of action of botulinum toxin B faster or slower than that of botulinum toxin A?
What are the complications associated with botulinum toxin injection for BEB?
bruising, belpharoptosis, ectropion, epiphora, diplopia, lagophthalmos
What are the clinical features of hemifacial spasm?
intermittent synchronous gross contractures of an entire side of the face
What is the most common cause of hemifacial spasm?
vascular compression of the facial nerve at the brain stem
What is blepharochalasis?
A rare familial variant of angioneurotic edema, commonly occurring in young females, that is characterized by episodes of inflammatory edema of the eyelids
What are three complications of blepharoplasty?
Loss of vision (may be due to orbital hemorrhage), diplopia (due to injury of inferior oblique, inferior rectus, or superior oblique), and excessive removal of eyelid skin
What are procedures for treating brow ptosis?
Browpexy, direct brow lift, and endoscopic or pretrichial brow lift
What 2 of the most important characteristics in evaluating a child with congenital tearing?
1) Frequency of tearing (constant vs. intermittent) and 2) Presence or absence of mucopurulent discharge
What does constant tearing with minimal mucopurulence in a child with congenital tearing suggest?
upper nasolacrimal system block caused by punctal or canalicular dysgenesis
What does constant tearing with frequent mucopurulence in a child with congenital tearing suggest?
complete obstruction of the NLD
What does intermittent tearing with mucopurulence in a child with congenital tearing suggest?
Intermittent obstruction of the NLD, consistent with impaction of a swollen inferior nasal turbinate, as might be expected with a URI
What is the most important maneuver in examining a child with congenital tearing?
digital pressure over the lacrimal sac
What does complete absence of the punctum and canalicular system necessitate?
What percent of all congenital NLD obstructions resolve in the first year of life?
What are conservative measures for NLD obstruction?
observation, lacrimal massage, topical antibiotics
What is referred to as the "hard stop" in NLDP?
encountering the nasal aspect of the lacrimal sac and the adjacent lacrimal bone
In what percent of patients under 13 months of age is NLDP successful at relieving obstruction?
Is NLDP performed in adults?
No, probing is generally limited to the canalicular system, and does not extend to the NLD as it is potentially traumatic and rarely successful in adults at relieving obstruction
Into what two categories can patients with true epiphora be grouped?
1) hypersecretion of tears, 2) impairment of drainage
What are the tests involved in evaluation of the lacrimal drainage system?
1) Dye disappearance test, 2) Jones I test, 3) Jones II test, 4) Lacrimal drainage system irrigation, 5) NLDP 6) Nasal endoscopy, 7) contrast dacryocystography or dacryoscintigraphy
What are the potential etiologies of canalicular obstruction?
1) lacrimal plugs, 2) chemotherapeutic meds (5-FU, docetaxel, idoxuridine), 3) Infection, 4) inflammation, 5) trauma, 6) neoplasm
What does conjunctivodacryocystorhinostomy (CDCR) involve?
A bypass of the lacrimal drainage system with a glass tube (Jones tube) placed through a new opening in the caruncle, through an osteotomy, and into the middle nasal meatus
What are the potential etiologies of acquired NLD obstruction?
1) Involutional stenosis, 2) dacryolith, 3) Sinus disesase, 4) trauma, 5) inflammatory disease (sarcoid), 6) lacrimal plugs, 7) radioactive iodine for thyroid malignancy, 8) Neoplasm
What does a dacryocystorhinostomy (DCR) involve?
The creation of an anastomosis between the lacrimal sac and the nasal cavity (to bypass the NLD) through a bony ostium, either by intranasal or transcutaneous approach.
Why do most surgeons recommend repair of all canalicular lacerations?
50% of patients with one functional canaliculus will still experience epiphora and primary repairs have a much higher likelihood of success than secondary reconstructions
How soon after injury should a canalicular repair be performed?
As soon as possible, preferably within 48 hours
What is the most common pathogen involved in canaliculitis?
Should irrigation or probing of the canalicular system be performed in acute dacryocystitis?
No, irrigation and probing should be avoided until the infection subsides