ANATOMIC STUDY OF THE ORBITAL SEPTUM (22.10.93)

The orbital septum separates the intraorbital fat from the palpebral p art of die orbicularis oculi m. An anatomic study after injection of c olorant into the intraorbital fat allows definition of a fibroadipose layer anterior to the orbital septum. This consists of radial fibers a nd extraorbital fatty lobules. The septum is derived embryologically f rom the mesenchyme of the second arch, but the structure of the anteri or layer remains controversial. The septum has an important mechanical function in containing the orbital fat and is involved in orbital mov ements. A knowledge of these different layers facilitates surgical app roaches and helps to define the anatomic landmarks in palpebral surger y for conditions such as ptosis and in blepharoplasty.