2020–2021 BCSC Basic and Clinical Science Course™
2 Fundamentals and Principles of Ophthalmology
Part I: Anatomy
Chapter 1: Orbit and Ocular Adnexa
Vascular Supply of the Eyelids
The blood supply of the eyelids is derived from the facial system, which arises from the external carotid artery, and the orbital system, which originates from the internal carotid artery along branches of the ophthalmic artery. Thus, the eyelid vasculature represents an anastomosis of the external and internal carotid arteries (Fig 1-36).
The marginal arterial arcade is located 3 mm from the free border of the eyelid, just above the ciliary follicles. It is either between the tarsal plate and the orbicularis oculi muscle or within the tarsus. A smaller peripheral arterial arcade runs along the upper margin of the tarsal plate anterior to the Müller muscle. The superficial temporal artery is a terminal branch of the external carotid artery and is discussed in greater detail in BCSC Section 5, Neuro-Ophthalmology. The venous drainage system of the eyelids can be divided into 2 components: a superficial (or pretarsal) system, which drains into the internal and external jugular veins, and a deep (or posttarsal) system, which flows into the cavernous sinus. Thus, the venous circulation of the eyelid connects the face with the cavernous sinus, providing a route for the spread of infection.
Figure 1-36 Arterial supply of the eyelids. Note the numerous locations where arteries emerging from the orbit anastomose with branches of the facial artery. The facial artery gives rise to the angular artery as it travels superiorly, lateral to the nose. The angular artery serves as an important landmark in dacryocystorhinostomy.
(Reproduced with permission from Dutton JJ. Atlas of Clinical and Surgical Orbital Anatomy. Philadelphia: Saunders; 1994.)
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.