Update on orbital anatomy

Abstract

The orbit is a confined space bounded by four bony walls. Apart from the globe, orbital fat, and extraocular muscles it contains many important neurovascular structures. It is intimately related to the paranasal sinuses as well as the anterior and middle cranial fossae. Consequently, sinus pathology and intracranial disease may spread to involve the orbit and the converse applies. A thorough understanding of orbital anatomy is essential to fully appreciate the effects of disease on the orbit and is of paramount importance for performing safe orbital surgery. The anatomy of the orbit is discussed with reference to relevant orbital disease.

Orbital size measurement based on computed tomography imaging for surgical safety

“…Based on the analysis of the obtained results it was established that the safe space (distance between the bony margin of the orbit and the optic canal) in each of the orbital wall is approximately 40 mm. Other authors obtained similar results [20,22].…”

“…In the present study this length was 43.78 mm in average (no statistically significant side to side and gender differences). This result was within the range obtained in the measurements of the distance from the frontozygomatic suture to the optic canal: 43.0 mm ÷ 47.1 mm [17,22].…”

“…That study was performed on Japanese subjects [19]. The angle between the medial and lateral wall of the orbit in the present study was 50.0° (no statistically significant side to side differences were observed, but the angle size was statistically significant greater in male gender), while other authors obtained a smaller angle of 45 o [22]. However, Dortzbach [7] emphasised that there is a large variety of angles between the orbital walls, depending on gender and ethnicity.…”

“…However, Dortzbach [7] emphasised that there is a large variety of angles between the orbital walls, depending on gender and ethnicity. The angles between the orbital walls (orbital geometry) determine the orbital volume [22]. Al-Sukhun et al [4] stated that the larger the orbital volume, the less resistant the orbit is to a trauma -a 1 mm difference in the wall spacing reduces the resistance by approximately 50%.…”

Variations in the topography of the infraorbital canal/groove complex: a proposal for classification and its potential usefulness in orbital floor surgery

“…It is believed that the groove mechanically weakens the inferior wall of the orbit. The orbital floor is relatively thin medial to the infraorbital nerve and can be fractured easily, and this is the portion of the floor which is usually removed during floor decompression [3,4,8,15,25,26].…”