2020–2021 BCSC Basic and Clinical Science Course™
2 Fundamentals and Principles of Ophthalmology
Part I: Anatomy
Chapter 1: Orbit and Ocular Adnexa
This chapter includes a related activity, which can be accessed by scanning the QR code provided in the text or going to www.aao.org/bcscactivity_section02.
Highlights
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The shortest, most direct path to the optic nerve is along the medial wall.
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Emissary channels in the medial wall of the orbit can facilitate the spread of infection from the ethmoid sinus into the orbit.
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The lesser wing of the sphenoid bone houses the optic canal.
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Fractures of the orbital floor can involve the infraorbital groove, which contains the infraorbital nerve, and should be suspected in cases of orbital trauma associated with infraorbital hypoesthesia.
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An imaginary line drawn externally between the extraocular muscle insertions approximates the ora serrata internally.
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At the annulus of Zinn, the medial and superior rectus muscles are adjacent to the optic nerve sheath. Because of this anatomical relationship, patients with retrobulbar optic neuritis experience pain with eye movement.
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The eyelid vasculature includes multiple sites of anastomoses between the external and internal carotid arteries.
Excerpted from BCSC 2020-2021 series: Section 2 - Fundamentals and Principles of Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.