Orbital size measurement based on computed tomography imaging for surgical safety

Abstract

Determining the orbital size makes it possible to manoeuvre safely within theorbit during a surgical procedure. Based on the measurements performed ona multi-layer head computed tomography images, the length was determined of the medial, superior, inferior and lateral orbital walls. Also angles were determined between the superior and inferior walls, between the medial and lateral walls, between the inferior wall and Frankfurt plane and between the anterior and posterior segments of the orbital wall. With these measurements it was possible to establish that the safe space for surgical exploration of the orbit (that is the space between the orbital margin and optic canal) is approximately 40 mm. Moreover, it was determined that the medial wall is parallel to the vertical axis of the body and that the angle between the inferior wall and the Frankfurt plane is 19.7°. The angle between the posterior segment of the inferior wall (posterior to the inferior orbital fissure) and the anterior segment is 130.8°. These data will significantly increase the safety of orbital surgeries.