2020–2021 BCSC Basic and Clinical Science Course™
6 Pediatric Ophthalmology and Strabismus
Part I: Strabismus
Chapter 3: Anatomy of the Extraocular Muscles
Orbital and Fascial Relationships
Within the orbit, a complex musculofibroelastic structure suspends the globe, supports the EOMs, and compartmentalizes the fat pads (Fig 3-5). In recent years, the interconnectedness of the orbital tissues, as well as the extent and complexity of these connections, has come to light. The intense fibrous connections existing throughout the orbit can be illustrated clinically by the consequences of tissue entrapment in blowout fractures and of fibrosis of delicate fibrous septa after retrobulbar hemorrhage. The nature of these relationships remains under investigation.
The eye is supported and cushioned within the orbit by a large amount of fatty tissue. External to the muscle cone, fatty tissue comes forward with the rectus muscles, stopping about 10 mm from the limbus. Fatty tissue is also present inside the muscle cone, kept away from the sclera by the Tenon capsule (see Fig 3-5).
Figure 3-5 The muscle cone contains 1 fat pad and is surrounded by another; these 2 fat pads are separated by the rectus muscles and intermuscular septum. Note that the intermuscular septum does not extend all the way back to the apex of the orbit.
(Modified with permission from Yanoff M, Duker J, eds. Ophthalmology. 2nd ed. London: Mosby; 2004:553.)
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.