The orbital septum (palpebral fascia) is a membranous sheet that acts as the anterior boundary of the orbit. It extends from the orbital rims to the eyelids. It forms the fibrous portion of the eyelids.
The right eye in sagittal section, with structures of the orbital septum within blue markings.
In the upper eyelid, the orbital septum blends with the tendon of the levator palpebrae superioris, and in the lower eyelid with the tarsal plate.
When the eyes are closed, the whole orbital opening is covered by the septum and tarsi. Medially it is thin, and, becoming separated from the medial palpebral ligament, attaches to the lacrimal bone at its posterior crest. The medial ligament and its much weaker lateral counterpart, attached to the septum and orbit, keep the lids stable as the eye moves.
With age the septum may weaken, and as a result orbital fat may herniate forwards. The operation to correct this is called blepharoplasty.
- Mahmood F. Mafee; Galdino E. Valvassori; Minerva Becker (10 November 2004). Imaging of the head and neck. Thieme. pp. 200–. ISBN 978-1-58890-009-8. Retrieved 16 June 2010.
- Meyer, D. R.; Linberg, J. V.; Wobig, J. L.; et al. (1991). "Anatomy of the orbital septum and associated eyelid connective tissues". Ophthalmic Plast Reconstr Surg. 7 (2): 104–113. PMID 1863562.
- "eye, human."Encyclopædia Britannica. 2008. Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2008"
- "Cellulitis, Orbital: eMedicine Ophthalmology". Retrieved 16 June 2010.