Fascia of orbit and eyeball

The fascia of the orbit and eyeball consists of connective tissue layers that support, stabilise, and facilitate movement of the eyeball within the orbit. The most important fascial structures include the periorbita, orbital septum, and fascial sheath of the eyeball (Tenon's capsule).

Periorbita

The periorbita is the periosteal lining of the bony orbit and is continuous with the cranial periosteum and dura mater at the optic canal and superior orbital fissure. Anteriorly, it blends with the orbital septum at the orbital margin.

Orbital septum

The orbital septum is a fibrous membrane extending from the orbital margins into the eyelids, where it blends with the tarsal plates. It acts as a barrier limiting the spread of infection between the eyelids and orbit.

Fascial sheath of eyeball

The fascial sheath of the eyeball (Tenons capsule) is a thin fibrous membrane that envelops the sclera from the optic nerve to the corneoscleral junction, separating the eyeball from orbital fat. The potential space between the sclera and Tenons capsule is called the episcleral (subTenons) space, allowing smooth eye movements. Fascial expansions from this sheath surround the extraocular muscles and contribute to the formation of the check ligaments (of lateral and medial recti muscles) and suspensory ligament of Lockwood, which help support the globe within the orbit.