Arcus Marginalis

The arcus marginalis is the name for a localized rim of thickening where the eyelid's orbital septum attaches to the orbital bone.

The term arcus marginalis release is sometimes used by blepharoplasty surgeons to describe a cosmetic operation on the lower eyelid in which fat surrounding the eyeball is moved out of the orbit and over the rim of orbital bone to try to fill in an upper cheek depression, or tear trough. To accomplish this, the arcus marginalis must be disinserted from its bony attachment.

The operation is better described by the term "lower eyelid fat repositioning," even though the fat moved is actually from the orbit rather than the eyelid.

More on eyelid fat repositioning