2020–2021 BCSC Basic and Clinical Science Course™
2 Fundamentals and Principles of Ophthalmology
Part I: Anatomy
Chapter 1: Orbit and Ocular Adnexa
Extraocular Muscle Insertions
The 4 rectus muscles insert anteriorly on the globe. Starting at the medial rectus muscle and proceeding to the inferior rectus, lateral rectus, and superior rectus muscles, the muscle insertions lie progressively farther from the limbus. An imaginary curve drawn through these insertions creates a spiral, called the spiral of Tillaux (Fig 1-16). The relationship between the muscle insertions and the location of the ora serrata is clinically important. A misdirected suture passed through the insertion of the superior rectus muscle could perforate the retina.
The superior oblique muscle, after passing through the trochlea in the superomedial orbital rim, inserts onto the sclera superiorly, under the insertion of the superior rectus. The inferior oblique muscle inserts onto the sclera in the posterior inferotemporal quadrant.
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.