Orbital Septum

The orbital septum is a fascia-like layer separating the eyelid tissues from the orbit, or deeper space within the socket containing the orbital fat and eyeball.

The orbital septum is a crucial landmark for blepharoplasty surgeons. Its attachment to the bone is called the arcus marginalis.

As an important structural layer, many modern operations are designed to spare the orbital septum from surgical damage during blepharoplasty. For instance, transconjunctival blepharoplasty is performed entirely behind the orbital septum to avoid the high risk of eyelid retraction that occurs when the orbital septum is opened to remove or reposition bulging fat.