The features of Tenon's capsule at the limbus.

Glaucomatous optic neuropathy is a multifactorial disease, whose most important risk is high intraocular pressure. Filtering surgery, i.e. trabeculectomy, is the operation of choice to lower pressure, allowing the aqueous to outflow from the anterior chamber under the conjuctiva and Tenon's capsule. Failure to establish a filtration bleb is due in most cases to subconjunctival fibrosis, leading to bleb encapsulation (Tenon's cyst). Our study aimed to locate the best cleavage plane for aqueous drainage. Based on histological data, the subtenonian space appears to satisfy this requirement, due to low scarring aptitude and low resistance.