Intraocular pressure and glaucoma.

Aqueous humor is a transparent fluid that fills the anterior and posterior chambers, and the pupil, of the eye. It is produced in the ciliary processes, and exits the eye through two major pathways--the iridocorneal (conventional) outflow, and the uveoscleral (unconventional) outflow. Equilibrium between production and drainage of aqueous humor enables the body to maintain constant intraocular pressure (IOP). Disruption of aqueous outflow, usually through the conventional pathway, results in elevation of IOP. This elevation in IOP is a major risk factor in the pathogenesis of glaucoma, a group of diseases characterized by decreased retinal function and progressive optic nerve damage that may result in blindness. This article reviews the anatomy and physiology of aqueous dynamics in exotic species, the causes, clinical signs and diagnosis of glaucoma, and therapeutic approaches.