aqueous humour flows from the posterior chamber to the anterior chamber of the eye through the pupil, and drains away via the trabecular meshwork, which lies at the angle where the iris meets the cornea. Schlemm’s canal, situated in the sclera, then conducts the aqueous humour into the venous system (James et al 2007). If the drainage angle is normal and open, but the trabecular meshwork is blocked, this leads to reduced aqueous drainage and a rise in intraocular pressure (Iop) (riordan-eva and Whitcher 2007). The increased Iop compresses the optic nerve, causing cell death and a progressive, gradual reduction in the visual field (Sharts-hopko and glynn-milley 2009).
Summary