Anterior Chamber Angle Assessment Techniques

The anterior chamber angle is the actual anatomical angle created by the root of the iris and the peripheral corneal vault. Within it lie the structures involved in the outflow passage of the aqueous, namely the trabecular meshwork and the Schlemm’s canal (figure 1). The depth of the angle in a healthy eye is approximately 30°, with the superior part usually less deep than the inferior half. However the depth is influenced by gender, age and refractive error. Female gender has the greatest influence on iridocorneal angle reduction, followed by age and spherical equivalent (Rufer et al.). The relationship of the iris plane to the cornea has a significant effect on the aqueous humor’s accessibility to its outflow drainage system. In eyes where the iris and corneal endothelium are “closed”against one another, the aqueous will not be drained causing an increase of the intraocular pressure (angle closure glaucoma) (Lens, 2008).