Glaucoma is a potentially blinding condition that cannot be easily defined. There are various types of glaucoma which may vary in symptoms from none at all to sudden pain and redness. There is a characteristic optic neuropathy, or damage to the optic nerve, which results in progressive loss of visual field. The most important risk factor is an increase in the intraocular pressure (IOP) secondary to a reduction in the drainage of aqueous fluid from the drainage pathways in the eye, the filtration angle (Kanski 2007, Allingham et al 2011).