Anatomy of the orbit, lacrimal apparatus, and lateral nasal wall.

Endoscopic approaches to the orbit take advantage of key anatomic relationships that arise from the fact that the sinonasal tract and orbit are contiguous structures separated by thin bone. For the most part, the orbit is surrounded by air-containing sinuses for much of the length of three of its four borders. Thus, a thorough understanding of both sinonasal and orbital anatomy is essential for safe and efficacious surgery in this complex region. The structural features of the lateral nasal wall and medial orbit are highlighted, and relevant aspects of orbital, lacrimal, and paranasal sinus anatomy are reviewed.