Orbit
- 1.
Name the bones of the orbit (see Fig. 2-1 ).
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Medial wall: Sphenoid, ethmoid, lacrimal, maxillary
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Lateral wall: Zygomatic, greater wing of the sphenoid
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Roof: Frontal, lesser wing of the sphenoid
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Floor: Maxillary, zygomatic, palatine
Figure 2-1
Anatomy of the orbit.
(From Kanski JJ: Clinical Ophthalmology: A Systematic Approach, ed 7, London, Elsevier, 2011.)
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- 2.
What are the weak spots of the orbital rim?
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Frontozygomatic suture
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Zygomaticomaxillary suture
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Frontomaxillary suture
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- 3.
Describe the most common location of blow-out fractures.
The posteromedial aspect of the orbital floor.
- 4.
What is the weakest bone within the orbit?
The lamina papyracea portion of the ethmoid bone.
- 5.
Name the divisions of cranial nerve V that pass through the cavernous sinus.
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Ophthalmic division (V1)
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Maxillary division (V2)
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- 6.
What is the annulus of Zinn?
The circle defined by the superior rectus muscle, inferior rectus muscle, lateral rectus muscle, and medial rectus muscle.
- 7.
What nerves pass through the superior orbital fissure but outside the annulus of Zinn?
Frontal, lacrimal, and trochlear nerves.
Eyelid
- 8.
List the factors responsible for involutional entropion.
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Lower lid laxity
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Override of the preseptal orbicularis oculi muscle onto the pretarsal orbicularis oculi muscle
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Dehiscence/disinsertion of the lower lid retractors
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Orbital fat atrophy
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- 9.
Describe the sensory nerve supply to the upper and lower eyelids.
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The ophthalmic nerve (V1) provides sensation to the upper lid.
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The maxillary nerve (V2) provides senssation to the lower lid.
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- 10.
What are the surgical landmarks for locating the superficial temporal artery during temporal artery biopsies?
The superficial temporal artery lies deep to the skin and subcutaneous tissue but superficial to the temporalis fascia.
- 11.
What structures would you pass through during a transverse blepharotomy 3 mm above the upper eyelid margin?
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Skin
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Pretarsal orbicularis muscle
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Tarsus
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Palpebral conjunctiva (see Fig. 2-2 )
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