Orbit 2 Flashcards
What are the 4 types of epicanthus skin folds?
- Epicanthus tarsalis: fold is more prominent in upper eyelid2. Epicanthus inversus: more prominent in lower eyelid3. Epicanthus palpebralis: equally upper and lower4. Epicanthus supraciliaris: Medial eyelid skin that is more prominent from eye brow to lacrimal sac
From where does the capsulopalpebral fascia originate?
The inferior rectus muscle
Vasculitides are what type of hypersensitivity reaction?
Type III
Wegener’s (granulomatosis with polyangiits) is characterized by what type of inflammation?
Necrotizing granulomatous vasculitis
Within the orbit, what structure is most commonly affected by sarcoidosis?
Lacrimal gland, usually bilateral
What are the top two locations for NSOI?
- Myositis (most common)2. Dacryoadenitis
What are known risk factors for developing capillary hemangiomas?
Premature infants and chorionic villus sampling
Orbital varices is what type of blood vessel abnormality?
veins
What are the two types of AV fistulas?
- CCF (secondary to trauma)2. Dural cavernous fistula (a degnerative process)
Neurofibroma is proliferation of what type of cell?
Schwann cell,
What is the inheritance pattern of NF1?
AD with incomplete penetrance
Where do meningiomas usually originate?
Sphenoid wing
What are the 4 types of rhabdomyosarcoma and which is most common, has the best prognosis and has the worst prognosis?
- Embryonal–most common, very good prognosis2. Alveolar–worst prognosis3. Pleomorphic–best prognosis4. Botryoid
What is the treatment of choice for isolated ocular lymphoma?
Radiotherapy; 2000-3000 cGy
What is thought to be the underlying cause of silent sinus syndrome?
Chronic, subclinical sinusitis that causes bone erosion that at some point causes collapse of the orbital floor resulting in enophthalmos
In adults, mets to the eye more frequently go to the choroid. Where do mets in children more commonly go?
The orbit
Which grade of Lefort fracture has no orbital involvement?
Grade 1
What are the 4 articulations in a ZMC (zygomaticomaxillary complex) involved (misnomer of tripod fracture)
- Zygomatic arch2. Zygomaticofrontal suture3. Zygomaticomaxillary suture 4. Zygomaticosphenoidal suture
gold weight is most commonly used for what type of lagophthalmos?
paralytic lagophthalmos
Medial spindle procedure is most commonly used for what?
Medial ectropion
Cutler-Bear procedure is most commonly used for what?
Upper eyelid defect greater than 50%
What part of the sphenoid bone (greater or lesser wings) does the optic nerve go through?
lesser wing of the sphenoid
When you are performing a canthotomy, what are you cutting?
The pretarsal orbicularis tendon (this is where superior and inferior pretarsal obicularis join)
The orbital septum originates at the arcus marginalis. Where does it insert? (Not that it is a muscle)
Superiorly it fuses 2-5mm above the superior tarsal border and inferiorly it fuses at the lower border of the inferior tarsus
What are the protractors of the eyes?
Orbicularis oculi
What are the retractors of the eye?
- Upper eye lid: levator and muller’s2. Lower eye lid: capsulopalpebral fascia and inferior tarsal muscle
The levator muscular portion is approximately 40mm long. How long is the apeuronotic portion? What is the ligament that traverses horizontally at the ligament/muscle junction?
14-20mm; Whitnall’s ligament
What is the analogous structure to Whitnall ligament in the lower eyelid?
Lockwood ligament. These ligaments act as structural support
Muller muscle originates how far from the superior tarsal border?
12-14mm on the undersurface of the levator
What is the vertical height of the superior tarsus? inferior tarsus?
10-12mm; 4mm
How many eye lashes are there in the upper and lower eyelids respectively?
100; 50
How many meibomian glands are there in the upper and lower respectively?
25; 20
What are the characteristics of blepharophimosis syndrome?
NAME?
Congenital ectropion is usually caused by what 3 conditions?
- Blepharophimosis syndrome2. Down syndrome3. Ichthyiosis
Coloboma of the medial upper eyelid is usually associated with systemic condition or isolated? Lower eyelid?
isolated (goldenhar however is associated with upper eyelid); associated with systemic syndrome
What location is sebaceous cell carcinoma more likely to occur?
Upper eyelid (more meibomian gland there)
What is eyelid imbrication syndrome?
When the upper eyelid is lax (with normal tarsus) and overrides the lower eyelid when sleeping causing chronic conjunctivitis
Trichoepithelioma
Remember PAPULE because it has a P in the name. Flat, flesh colored papule.
Trichofolliculoma
Remember Umbilicated because it has a U in the name. sometimes these lesions are umbilicated
Trichilemmoma
The 3rd “trichi” hair follicle tumor is verrucous appearing
What are the 4 types subtypes of basal cell carcinoma. Which is most common? Which is most aggressive?
- Nodular (most common)2. Ulcerative3. Pigmented4. Morpheaform (most aggressive)
Complete preoperative metastatic work-up is indicated for melanomas larger than what?
1.5mm
Is lentigo simplex related to sun exposure?
No
When are tears first produced after birth and when does the lacrimal drainage system mature to function?
20 days; 6 weeks
What is the normal upper eyelid crease distance in males? In females?
8-9; 9-11
What is an easy exam finding to help differentiate acquired vs congenital myogenic ptosis?
Ptotic eyelid is elevated on downgaze (compared with normal eye) with congenital myogenic ptosis
What is the most common complication of blepharoptosis surgery?
Undercorrection
Is benign essential blepharospasm bilateral or unilateral?
Bilateral
Does hemifacial spasms occur during sleep?
Yes; unlike benign essential blepharospasm
Where is the peripheral arterial arcade located of the eyelid?
Just superior to the superior tarsus border between muller and levator muscles
