Depending on the definition, Glaucoma is the world’s first or second leading cause of blindness, affecting about 3.7% of persons over the age of 40 years. Glaucoma is the progressive death of optic nerve-fibres, which ultimately disconnects the retina from the brain. The commonest types of glaucoma have almost no symptoms. It was thought that glaucoma was caused by internal eye pressure that is too high. Basically, the eyes are fluid-filled balls that are lightly pressurised to keep their spherical shape. In fact, about half of all glaucoma patients have normal eye pressure, they are just more susceptible to damage by the pressure they have. At the same time the eyes of many people are not damaged by even moderately high pressures. So on its own eye pressure is poorly diagnostic. Fortunately, lowering eye pressure is an effective treatment for all glaucoma patients, even those with normal pressure who are pressure-intolerant. Pressure lowering can be done by eye drops, laser treatments or surgery: more serious cases needing more serious treatment. Who and when to treat are the issues.
The focus of damage appears to be the rim (edge) of the optic disc. Due to the way the eye develops the retinal nerve-fibres coming to the disc arrive in arc-shaped bundles. This means that if the fibres at a point on the rim are damaged that will cause arc-shaped swaths of the retina to become detached from the brain. This leads to the arc and sector shape losses of visual sensitivity that are characteristic of glaucoma. Unfortunately, current technologies for tracking progression of glaucoma are poor, making it difficult for doctors to make treatment decisions.
Vison ACTion and their Partners have already commercialised new test methods and are working on more objective devices that already have FDA clearance.