Orbital septum
The orbital septum is a membranous sheet that acts as the anterior boundary of the orbit
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents...

. It extends from the orbital rims to the eyelid
An eyelid is a thin fold of skin that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily...

s. It forms the fibrous portion of the eyelids.


In the upper eyelid it blends with the tendon of the Levator palpebræ 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
Medial palpebral ligament
The medial palpebral ligament , about 4 mm. in length and 2 mm. in breadth, is attached to the frontal process of the maxilla in front of the lacrimal groove....

, attaches to the lacrimal bone at its posterior crest
Posterior lacrimal crest
The lateral or orbital surface of the lacrimal bone is divided by a vertical ridge, the posterior lacrimal crest, into two parts.In front of this crest is a longitudinal groove, the lacrimal sulcus , the inner margin of which unites with the frontal process of the maxilla, and the lacrimal fossa is...

. The medial ligament and its much weaker lateral counterpart, attached to the septum and orbit, keep the lids stable as the eye moves.

The septum is perforated by the vessels and nerves which pass from the orbital cavity to the face
The face is a central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can, depending on the definition in the human case, include the hair, forehead, eyebrow, eyelashes, eyes, nose, ears, cheeks, mouth, lips, philtrum, temple, teeth, skin, and...

 and scalp
The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly.-Layers:It is usually described as having five layers, which can conveniently be remembered as a mnemonic:...


Clinical significance

With age the septum may weaken, and as a result orbital fat may herniate forwards. The operation to correct this is called blepharoplasty
Blepharoplasty is surgical modification of the eyelid. Excess tissue such as skin and fat are removed or repositioned, and surrounding muscles and tendons may be reinforced. It can be both a functional and cosmetic surgery.-Indications:...


The orbital septum is an important landmark in distinguishing between orbital cellulitis
Orbital cellulitis
Orbital cellulitisis an infection of eye tissues posterior to the orbital septum. It most commonly refers to an acute spread of infection into the eye socket from either the adjacent sinuses or through the blood...

 and periorbital cellulitis
Periorbital cellulitis
Periorbital cellulitis, also known as preseptal cellulitis , is an inflammation and infection of the eyelid and portions of skin around the eye, anterior to the orbital septum...

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