Glaucoma has been called the “silent thief of sight” as it is asymptomatic but causes irreversible vision loss. One of the most common ophthalmic conditions in the world, it is also the leading cause of irreversible blindness (World Health Organization, 2010). In England and Wales, it is the second most common cause for registration of visual impairment (Bunce et al, 2010). Glaucoma is an umbrella term for a large group of disorders characterised by diverse clinical and pathological features. The common characteristics are:
Optic nerve damage;
Visual field loss; and
Irreversible blindness.