The orbit and ocular adnexa are susceptible to several, primary and secondary diseases affecting various tissue, types such as osseous, vascular, neural, muscular, and, glandular structures (see Chapters 44 and 45).1-3 These, include primary tumors, infections, and inflammations,, as well as secondary disease from the periorbital paranasal, sinuses, eyelids, and brain., Given the intricate anatomy of the orbit, it is no wonder, that most primary and secondary orbital diseases share, the common symptoms of proptosis, strabismus, and, optic nerve compression. Clearly, diagnosis of orbital, pathologies requires a meticulous approach, leading to, an assessment of urgency and often tissue diagnosis., A comprehensive assessment begins with a thorough, ophthalmic and systemic history, considering the chief, complaint(s), major ophthalmic symptoms, their onset,, and duration (see Chapter 3). This information, coupled, with a meticulous ophthalmic examination and, radiologic imaging, typically forms the bedrock for establishing, a presumptive diagnosis and course of medical or, surgical management.