The detection and management of primary open angle glaucoma is a major healthcare issue. It is the second largest cause of blindness in the world and affects some 66.8 million people, leaving 6.7 million with bilateral blindness.1 In the United Kingdom, the ageing of the population means that the number of cases is expected to increase by 30% in the next 20 years.2

In primary open angle glaucoma, the retinal ganglion cells—the nerves that carry the visual stimulus from the retina to the brain—undergo apoptosis after insult at the head of the optic nerve. The progressive loss of ganglion cells leads to characteristic structural changes at the head of the optic nerve and functional loss to the visual field. Glaucoma is often, but not necessarily, associated with …