Update on orbital anatomy.

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.