This is an exciting time to be working in the field of glaucoma research, says Professor Keith Martin, President of the World Glaucoma Association. “In terms of innovation and new treatments, glaucoma was trailing behind other eye diseases, such as macular degeneration,” he notes. But now a number of interesting breakthroughs are beginning to emerge.

In its early stages, glaucoma — a deterioration of the optic nerve, which first affects peripheral vision — often has no symptoms. “That's why the disease is known as 'the silent thief of sight',” says Martin. “Vision can become slightly blurry at the periphery, but this might not be noticed until central vision is affected. By then it's often too late to reverse the damage.”

If you are of Afro-Caribbean origin, or very shortsighted, you should be tested more often

Early diagnosis is vital because treatment is available that can slow the progress of the disease. An optician will look at your optic nerve, measure your visual field and test the pressure within your eyes. It's sensible for people under 40 to have an eye examination every five years; although if you have a family history of glaucoma, or are of Afro-Caribbean origin, or very shortsighted, then your risk is increased so you should be tested more often. As the risk of glaucoma increases with age, those over 40 should also have more frequent eye examinations.

Glaucoma patients can present with increased pressure inside the eyes, known as intraocular pressure, or IOP. However, it should be stressed that even those with normal levels can develop glaucoma. To treat the disease effectively, it's important to lower pressure, which can be done using eye drops, laser treatment or surgery.

“Controlling the pressure in your eyes over the course of 24 hours reduces the risk of the disease getting worse,” says Martin. “The problem is, most studies show that only half the people who are prescribed treatment actually use it. They may take eye drops for a while but then either forget or give up. But if you have been prescribed eye drops, you must use them every day.”

Once-a-day eye drops are preferred

Anything that can be done to make treatment less burdensome for the patient should be welcomed. “That might mean developing better tolerated eye drops or simply making eye drop bottles easier to open,” says Martin. The more eye drops patients are given the less likely they are to use them, which is one reason why eye drops that only need to be used once a day rather than two to four times a day have been an important advance.

In the last few years, a range of fluid-draining devices have been developed that can be implanted in the eye via minimally invasive surgery. “These devices are designed to lower IOP and reduce the need for eye drops,” says Martin. “Unfortunately, we don't know — yet — how they will work over the long-term; plus they may be less appropriate in the treatment of severe or advanced glaucoma, where very low eye pressures are required. So there is still more research to be done in this area to develop new devices that achieve even lower eye pressures in the long term.

“However, we now understand more about the pathology of the disease and this is opening up the possibility of treating glaucoma with gene therapy and stem cell therapy. We're starting to learn how to restore function to the injured optic nerve, and while the work is still at an early stage and confined to animals, techniques to regenerate the optic nerve are also evolving rapidly. In future there is the prospect that we may be able to improve the vision of glaucoma patients, as well as being able to slow the decline of the disease.”