Pathophysiology
Intraocular pressure is mainly maintained by the liquid aqueous humor, which is produced by the ciliary body of the eye. Aqueous humor normally does not go into the posterior segment of the eye; it is kept out of this area by the lens and the Zonule of Zinn. Instead, it stays only in the anterior segment, which is divided into the anterior and posterior chambers. While the anterior and posterior chambers are very similarly named to the anterior and posterior segments, they are not synonymous. The anterior and posterior chambers are both parts of the anterior segment, which is an important distinction to make in the understanding of the two main mechanisms of ocular hypertension.
When the ciliary bodies produce the aqueous humor, it first flows into the posterior chamber (bounded by the lens and the iris). It then flows through the pupil of the iris into the anterior chamber (bounded by the iris and the cornea). From here, it flows through a structure known as the trabecular meshwork to enter the normal body circulation. Thus, the two main mechanisms of ocular hypertension are an increased production of aqueous humor, or a decreased outflow of aqueous humor.
Read more about this topic: Ocular Hypertension