Microscopic Anatomy of Orbital Septum.

PURPOSE: To study the microscopic anatomy of the orbital septum and evaluate its relationships with the adjoined structures.

METHODS

Histological evaluation of 11 upper eyelids (5 right, 6 left) from 10 Japanese cadavers (age range: 36-94-year-old, average: 71.1) was performed. The specimens were fixed in 10% formalin and stained with Elastica Van Gieson. Specimens were microscopically analyzed using different magnifications (20×, 40×, and 100×).

RESULTS

The orbital septum was the single fibrous layer in all the specimens, anteriorly separated from the retro-orbicularis fat pad capsule and posteriorly from the preaponeurotic fat pad capsule. At the junction of the orbital septum with the levator aponeurosis, the orbital septum proceeded towards the tarsal plate, and the preaponeurotic fat pad capsule reflected posteriorly.

CONCLUSIONS

The orbital septum is constituted of a single layer of fibrous tissue anteriorly separated from the retro-orbicularis fat pad capsule and posteriorly from the preaponeurotic fat pad capsule by the corresponding virtual spaces.