2020–2021 BCSC Basic and Clinical Science Course™
7 Oculofacial Plastic and Orbital Surgery
Part I: Orbit
Chapter 1: Orbital Anatomy
Sound knowledge of orbital anatomy is the foundation for diagnosis and management of orbital diseases.
The orbit is composed of 7 bones that create a quadrilateral pyramid, which condenses to 3 walls at the orbital apex.
Each of the orbital walls contains important landmarks and can be involved in disease processes.
The optic canal and superior and inferior orbital fissures transmit the critical neurovascular structures of the orbit and can be anatomically subdivided by the annulus of Zinn.
The vasculature of the orbit arises from the ophthalmic artery by way of the internal carotid artery. Branches of the ophthalmic artery subsequently form anastomoses with branches of the external carotid in the eyelid and periorbital region.
The 4 paranasal sinuses are immediately adjacent to the orbit; they are rudimentary or very small at birth, developing and enlarging during childhood and adolescence.
Pathologic processes in the paranasal sinuses can contribute to numerous diseases of the orbit.
BCSC Section 2, Fundamentals and Principles of Ophthalmology, also discusses ocular anatomy and includes many illustrations.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.