BCSC Plastics Flashcards
1
Q
Are capillary hemangiomas in children benign or malignant?
A
Benign, but may cause mass effect
2
Q
When do capillary hemangiomas usually present?
A
birth to first few weeks of life, enlarging over first 6-12 months
3
Q
What percent of capillary hemangiomas resolve within the first 4-5 years of life?
A
75%
4
Q
Is CVS a risk factor for capillary hemangioma?
A
Yes
5
Q
How can MRI be used to distinguish capillary hemangiomas from other vascular malformations?
A
MRI will show fine vascular channels and high blood flow
6
Q
What part of the orbit do capillary hemangiomas have a propensity for?
A
superonasal quadrant
7
Q
What are the major complications of capillary hemangiomas?
A
Amblyopia, strabismus, and anisometropia
8
Q
What are possible treatments for capillary hemangiomas?
A
topical or systemic beta blockers, steroids, surgical excision
9
Q
What is the most common benign neoplasm of the orbit in adults?
A
Cavernous hemangioma
10
Q
What is the histology of the cavernous hemangioma?
A
The lesions are encapsulated and composed of large cavernous spaces containing RBCs. The walls contain smooth muscle
11
Q
Are arteriography and venography useful in evaluation of cavernous hemangiomas?
A
No, there is little communication with the systemic circulation
12
Q
What is the management of cavernous hemangioma?
A
Surgical excision after imaging if there is compromise of ocular function
13
Q
Are hemangioperictyomas common?
A
No
14
Q
What is the histology of the hemangiopericytoma?
A
Plump pericytes surround a rich capillary network
15
Q
When do lymphatic malformations (lymphangiomas) generally present?
A
Within the first decade of life in the orbit
16
Q
What is the histology of the lymphatic malformation?
A
They generally contain both lymphatic and venous components and are characterized by large, serum-filled channels that are lined by flat endothelial cells
17
Q
Are lymphatic malformations technically neoplasms?
A
No, because their endothelial cells do not proliferate
18
Q
What are the features of lymphatic malformations on MRI?
A
multiple grape-like cystic lesions with fluid-fluid layering of the serum and red blood cells
19
Q
How can a venous malformation be diagnosed?
A
With demonstration of engorgement on spiral CT during a Valsalva maneuver (decreasing venous return)
20
Q
What is the management oforbital venous malformations?
A
Conservative, with surgical excision only if there is vision-threatening compressive optic neuropathy; embolization with coils may also be employed
21
Q
What are arteriovenous fistulas?
A
acquired lesions caused by abnormal direct communication between an artery and a vein
22
Q
What are the possible causes of an AV fistula?
A
Trauma or degeneration
23
Q
What are the 2 forms of AV fistula?
A
Carotid cavernous fistula (typically occurs after a basal skull fracture) and Spontaneous Dural Cavernous Fistula (degenerative process in older pts with HTN and atherosclerosis)
24
Q
Do carotid cavernous fistulas have high blood flow?
A
Yes
25
What are findings associated with carotid cavernous fistula?
Tortuous epibulbar vessels, audible bruit, pulsatile proptosis
26
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
27
How do Dural Cavernous Fistulas occur?
small meningeal arterial branches communicate with venous drainage
28
How does chronic red eye occur in Dural Cavernous Fistula?
Arterialization of the conjunctival vessels
29
How is embolization of AV fistulas usually accomplished?
endovascular transarterial route
30
What are the types of neural tumors of the orbit?
optic nerve gliomas, neurofibromas, meningiomas, and schwannomas
31
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
32
What is the prognosis for malignant optic nerve gliomas?
Very poor -- usually death within 6-12 months even with treatment
33
What percent of optic nerve gliomas are associated with neurofibromatosis?
50%
34
What are the clinical findings of optic nerve glioma?
gradual, painless, unilateral axial proptosis associated with loss of vision and an afferent pupillary defect
35
What is the gross pathology of the optic nerve glioma?
Smooth, fusiform intradural lesion
36
Where do optic nerve gliomas in patients with NF usually proliferate?
the subarachnoid space
37
What are the findings of optic nerve glioma on CT or MRI?
fusiform enlargement of the optic nerve with sterotypical kinking of the nerve
38
What are the possible treatment options for optic nerve glioma?
Observation only, surgical excision, radiation therapy, radiation therapy
39
Of what are neurofibromas composed?
proliferating Schwann cells within nerve sheaths with occasional axons, endoneural fibroblasts, and mucin
40
What are the two types of neurofibromas?
PlexiformNeurofibromas and Discrete Neurofibromas
41
Which type of neurofibroma (plexiform or discrete) is easier to excise surgically?
Discrete
42
In which form of neurofibromatosis do plexiform neurofibromas usually occur?
NF 1
43
What is the inheritance of NF 1?
autosomal dominant with incomplete penetrance
44
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
45
What are meningiomas?
Invasive tumors arising from the arachnoid villi
46
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
47
What is the most common primary orbital malignancy of childhood?
Rhabdomyosarcoma
48
What is the average age of onset of rhabdomyosarcoma?
8-10 yrs
49
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
50
From what do rhabdomyosarcomas arise?
Undifferentiated pluripotential mesenchymal elements of the orbital soft tissues (not from the extraocular muscles)
51
What are the 4 categories of rhabdomyosarcoma?
Embryonal, Alveolar, Pleomorphic, Botryoid
52
What is the common management of rhabdomyosarcoma?
Biopsy via anterior orbitotomy, surgical excision if there is a pseudocapsule, chemo and radiation, possible exenteration
53
What is the most common form of rhabdomyosarcoma?
Embryonal (80%)
54
Which form of rhabdomyosarcoma has the worst prognosis?
Alveolar, 10-year survival rate 10%
55
Which form of rhabdomyosarcoma has the best prognosis?
Pleomorphic, 97% survival rate
56
What portion of orbital tumors are lymphoproliferative neoplasms?
20%
57
What is the most common type of orbital lymphoproliferative disease?
Malignant non-Hodgkin B-cell lymphoma
58
What percent of orbital lymphomas are MALT lesions?
40%-50%
59
What percent of patients with orbital MALT will develop systemic disease at 10 years?
50%
60
What is the classic clinical presentation of a lymphoproliferative lesion?
Gradually progressive painless mass
61
What is the classic clinical appearance of a lymphoproliferative lesion?
Salmon patch underneath the conjunctiva or located anteriorly in the orbit
62
What type of biopsy is preferred for lymphoproliferative lesions?
Open biopsy
63
What percent of orbital lymphoproliferative lesions have on diagnosis or will have associated systemic disease within 5 years?
50%
64
What is the treatment of choice for localized orbital lymphoproliferative lesions?
Radiation, with a dose of 2000 to 3000 cGy
65
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)
66
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)
67
What do most lacrimal gland masses represent?
Non-specific inflammation of the lacrimal gland (dacryoadenitis)
68
What is a common dichotomy of lacrimal gland tumors?
Epithelial origin vs. non-epithelial origin
69
What is the most common epithelial tumor of the lacrimal gland?
The pleomorphic adenoma (benign mixed tumor)
70
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
71
Should a suspected pleomorphic adenoma of the lacrimal gland be biopsied?
No, it should be completely excised surgically maintaining an intact pseudocapsule
72
What is the most common malignant tumor of the lacrimal gland?
The adenoid cystic carcinoma (cylindroma)
73
What percent of patients with orbital neuroblastoma survive?
90% if diagnosed before age 1, 10% if diagnosed after age 1
74
What is the most common type of leukemia to metastasize to the orbit?
Acute lymphoblastic leukemia
75
What are the two most common metastases to the orbit?
Breast and lung tumors
76
What is the most common orbital metastasis in women?
Breast carcinoma
77
What is the most common orbital metastasis in men?
Bronchogenic carcinoma
78
What part of the face do Le Fort fractures involve?
the maxilla
79
What is a Le Fort I fracture?
a low transverse maxillary fracture above the teeth with no orbital involvement
80
What is a Le Fort II fracture?
a pyramidal fracture involving the nasal, lacrimal, and maxillary bones, as well as the medial orbital floor
81
What is a Le Fort III fracture?
craniofacial disjunction with involvement of the orbital floor and medial and lateral orbital walls
82
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
83
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
84
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
85
What is another name for a direct medial orbital fracture?
A naso-orbital-ethmoidal fracture
86
What are the common clinical characteristics of a nas-orbital-themoidal fracture?
Depressed bridge fo the nose and traumatic telecanthus
87
What is an indirect medial orbital fracture?
A fracture of the medial orbit resulting from a blowout fracture of the orbital floor
88
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
89
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
90
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)
91
Can MRI be safely performed with a BB in the orbit?
Yes
92
Should BBs be removed from the orbit when found?
Usually, they are best left in place
93
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)
94
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)
95
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
96
If used in orbital surgery, how long is a drain generally kept in place
no more than 24-36 hours
97
Should visual acuity be checked frequently after orbital surgery?
Yes, especially in the first 12 hours after surgery
98
Should patching of the operative site be performed after orbital surgery?
No, since this can delay diagnosis of postoperative hermorrhage
99
In which situations is enucleation the anophthalmic surgery of choice?
If the nature of intraocular pathology is unknown or if ocular tumor is suspected
100
What is a benefit of enucleation over evisceration?
Lower likelihood of sympathetic ophthalmia, particularly with severely traumatized eyes
101
Which are the ocular tumors that most commonly require enucleation?
Retinoblastoma and choroidal melanoma
102
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
103
What surgical approaches can be used for obtaining exposure for enucleation?
lateral canthotomy or superomedial approach
104
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
105
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
106
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
107
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
108
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
109
What are the different classes of spherical orbital implants?
Inert (glass, silicone, MMA) and Biointegrated (hydroxyapatite, porous polyethylene)
110
What are possible locations for orbital implants?
Within the Tenon capsule or behind the posterior Tenon capsule in the muscle cone
111
When is an ocular prosthesis usually fitted after anophthalmic surgery?
4-8 weeks
112
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
113
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)
114
What are the types of orbital exenteration?
Subtotal, Total, and Extended
115
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
116
How are the mimetic muscles divided?
Upper face and lower face (superficial and deep)
117
Which muscles animate the forehead and glabella?
frontalis, corrugator, and procerus
118
Which muscle depresses the eyebrows and closes the eyelids?
orbicularis oculi
119
Which muscle elevates the eyebrows?
frontalis
120
Which muscles are the superficial mimetic muscles?
platysma, zygomaticus major, zygomaticus minor, risorius
121
Which muscles are the deep mimetic muscles?
buccinator, mentalis, levator anguli oris
122
What are the 5 major branches of the facial nerve (CN VII)?
Temporal, zygomatic, buccal, marginal mandibular, cervical
123
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
124
What defines the upper eyelid crease?
The attachments of the levator aponeurosis to the pretarsal orbicularis bundles and skin
125
What defines the upper eyelid fold?
the loose preseptal skin and sucutaneous tissues above the confluence of the levator aponeurosis and orbital septum
126
What are the divisions of the orbicularis oculi muscle?
Orbital, pre-septal, and pre-tarsal
127
Which divisions of the orbicularis oculi muscle are involved in involuntary movement of the eyelids?
Pre-septal and pre-tarsal
128
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
129
Where does the orbital septum fuse with the capsulopalpebral fascia in the lower eyelid?
At or below the inferior tarsal border
130
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
131
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.
132
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)
133
What are the retractors of the upper lid?
Levator muscle (with levator aponeurosis) and superior tarsal muscle (Muller muscle)
134
What are the retractors of the lower lid?
Capsulopalpebral fascia and inferior tarsal muscle
135
Where is the peripheral arterial arcade found?
between the levator aponeurosis and the Muller muscle, just above the superior tarsal border
136
How tall are the superior and inferior tarsal plates?
10-12mm (superior) and 4mm (inferior)
137
How are the tarsal plates connected to the periosteum of the orbit?
Via the medial and lateral canthal tendons
138
Where is the mucocutaneous junction of the eyelid located?
Just posterior to the meibomian gland orifices on the eyelid margin
139
When do most congenital anomalies of the eyelids occur?
During the second month of gestation
140
What are the components of Blepharophimosis Syndrome?
Blepharophimosis, telecanthus, epicanthus inversus, severe ptosis.
141
What are the common associations of congenital ectropion?
Blepharophimosis syndrome, Down syndrome, and icthyosis
142
What is euryblepharon?
From the Greek eurus, meaning "wide" -- unilateral or bilateral horizontal widening of the palpebral fissure, sometimes associated with blepharophimosis syndrome
143
What is ankyloblepharon?
From the Greek prefix ankyl, meaning "stiff, unmovable, adhesion" -- partial or complete fusion of the eyelids by webs of skin
144
What is epicanthus?
a medial canthal fold that may result from immature midfacial bones or a fold of skin and subcutaneous tissue
145
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
146
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.
147
What is congenital distichiasis?
A rare, sometimes hereditary condition in which an extra row of lashes is present in place of meibomian gland orifices
148
Which skin is usually used for grafting eyelid defects?
Contralateral eyelid or pre-auricular or post-auricular skin
149
Should hair-bearing skin grafts be used around the eye?
No, they should be avoided if possible
150
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
151
Under what condition can direct closure of an upper eyelid defect be performed?
<= 33% of the eyelid margin is involved.
152
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.
153
How many days prior to elective periocular surgery is warfarin generally stopped?
2-5 days, if approved by PCP
154
How many days prior to elective periocular surgery is aspirin generally stopped?
5 days, if approved by PCP
155
How many days prior to elective periocular surgery are NSAIDs generally stopped?
3 days, if approved by PCP
156
What are the five classes of ectropion?
1) congenital; 2) involutional; 3) paralytic; 4) cicatricial; 5) mechanical
157
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)
158
Does involutional ectropion usually affect the upper or lower lid?
Lower lid
159
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
160
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
161
What are the 4 types of entropion?
1) congenital; 2) acute spastic; 3) involutional; 4) cicatricial
162
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
163
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)
164
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)
165
What are the three types of procedures for repair of involutional entropion?
1) Temporizing measures, 2) Horizontal tightening procedures, 3) repair of the retractors
166
What are common temporizing measures for repair of involutional entropion?
Quickert sutures and thermal cautery
167
What are the three etiologic factors in involutional entropion?
1) disinsertion of the eyelid retractors, 2) overriding orbicularis, 3) horizontal laxity
168
How quickly can trichiasis recur after mechanical epilation?
3-8 weeks
169
What are the therapies available for trichiasis?
Mechanical epilation, electrolysis, radiofrequency ablation, cryotherapy, argon laser, full-thickness pentagonal resection with primary closure
170
What are the five etiologic variants of ptosis (blepharotosis)?
1) myogenic, 2) aponeurotic, 3) neurogenic, 4) mechanical, 5) traumatic
171
What is the most common etiology of congenital ptosis?
poorly developed levator muscle (myogenic cause)
172
What is the most common etiology of acquired ptosis?
stretching or disinsertion of the levator aponeurosis (aponeurotic cause)
173
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
174
What is MRD1?
the distance from the upper eyelid margin to the corneal light reflex in primary position (may be zero or negative)
175
What is MRD2?
the distance from the corneal light reflex to the lower eyelid margin
176
What does the sum of MRD1 and MRD2 represent?
The vertical interpalpebral fissure height
177
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)
178
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
179
Does ptosis tend to improve or worsen in downgaze when congenital?
Congenital ptosis improves in downgaze, unlike acquired ptosis, which worsens.
180
Is the crease in the typical Asian eyelid higher or lower than in the typical Caucasian eyelid?
lower
181
What percent of patients with congenital ptosis develop amblyopia?
20%
182
What congenital conditions involve both EOM dysfunction and ptosis?
1) combined superior rectus/levator muscle maldevelopment; 2) congenital oculomotor palsy
183
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
184
What conditions involve both ptosis and pupillary abnormalities?
1) Horner syndrome, 2) CN III palsy
185
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)
186
What is the most common etiology of congenital myogenic ptosis?
dysgenesis of the levator muscle
187
What are common causes of acquired or late-onset myogenic ptosis?
muscular dystrophy, chronic progressive external ophthalmoplegia, oculopharyngeal dystrophy
188
What is the most common form of ptosis?
Acquired aponeurotic ptosis
189
What is the mechanism of aponeurotic ptosis?
stretching or dehiscence of the levator aponeurosis or disinsertion from its normal position
190
Is the upper eyelid crease usually higher or lower than normal in acquired aponeurotic ptosis?
higher
191
What are the causes of congenital neurogenic ptosis?
Congenital CN III palsy, congenital Horner syndrome, Marcus-Gunn jaw-winking syndrome
192
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)
193
What is the analog of the Muller muscle in the lower lid?
The inferior tarsal muscle
194
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)
195
What are the two common causes of acquired oculomotor nerve palsies?
1) Ischemic (can be self-limited, especially if pupil-sparing) and 2) Compressive
196
What percent of myasthenia gravis patients have thymomas?
10%, thus warranting consideration of chest CT scanning at time of diagnosis
197
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
198
What are the common medical treatments for myasthenia gravis?
acetylcholinesterase inhibitors and steroids
199
What surgical intervention is sometimes performed for myasthenia gravis after medical treatments are attempted?
frontalis suspension
200
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
201
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
202
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
203
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)
204
What is the most common cause of paralytic ectropion?
CN VII paralysis or palsy
205
What is the most commonly performed procedure for treatment of paralytic lagophthalmos?
gold weight loading of the upper eyelid
206
Is neuroimaging indicated in the workup of blepharospasm?
usually not
207
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
208
What is the treatment of choice for Benign Essential Blepharospasm (BEB)?
repeated periodic injection of botulinum toxin A
209
What are the kinetics of botulinum toxin A injections?
Onset: 2-3 days, Peak effect: 7-10 days, Duration of action: 3-4 months
210
Is the onset of action of botulinum toxin B faster or slower than that of botulinum toxin A?
faster
211
What are the complications associated with botulinum toxin injection for BEB?
bruising, belpharoptosis, ectropion, epiphora, diplopia, lagophthalmos
212
What are the clinical features of hemifacial spasm?
intermittent synchronous gross contractures of an entire side of the face
213
What is the most common cause of hemifacial spasm?
vascular compression of the facial nerve at the brain stem
214
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
215
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
216
What are procedures for treating brow ptosis?
Browpexy, direct brow lift, and endoscopic or pretrichial brow lift
217
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
218
What does constant tearing with minimal mucopurulence in a child with congenital tearing suggest?
upper nasolacrimal system block caused by punctal or canalicular dysgenesis
219
What does constant tearing with frequent mucopurulence in a child with congenital tearing suggest?
complete obstruction of the NLD
220
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
221
What is the most important maneuver in examining a child with congenital tearing?
digital pressure over the lacrimal sac
222
What does complete absence of the punctum and canalicular system necessitate?
conjunctivodacryocystorhinostomy (CDCR)
223
What percent of all congenital NLD obstructions resolve in the first year of life?
90%
224
What are conservative measures for NLD obstruction?
observation, lacrimal massage, topical antibiotics
225
What is referred to as the "hard stop" in NLDP?
encountering the nasal aspect of the lacrimal sac and the adjacent lacrimal bone
226
In what percent of patients under 13 months of age is NLDP successful at relieving obstruction?
90%
227
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
228
Into what two categories can patients with true epiphora be grouped?
1) hypersecretion of tears, 2) impairment of drainage
229
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
230
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
231
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
232
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
233
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.
234
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
235
How soon after injury should a canalicular repair be performed?
As soon as possible, preferably within 48 hours
236
What is the most common pathogen involved in canaliculitis?
Actinomyces israelii
237
Should irrigation or probing of the canalicular system be performed in acute dacryocystitis?
No, irrigation and probing should be avoided until the infection subsides
238
Are topical antibiotics effective in treating acute dacryocystitis?
No, not usually. Oral or parenteral antibiotics are usually required.
