Image that, as you read on your computer screen, the many pixels on the screen begin to stop working, a few at a time... not right in the center, but in clusters all around the screen. It happens slowly, eventually wiping out all but a tiny central spot... which eventually drops out, too. The screen is blank then.
That's a pretty close analogy of what happens when glaucoma runs its course. You'll start losing your peripheral vision first, one eye at a time, and you likely won't even realize that it's happening until much of the damage has been done. The damage is irreversible, but the process can be stopped with early detection and treatment.
Are you at risk?
Glaucoma is the second-leading cause of blindness in the world after cataracts, and it mostly affects people as they age past 60. The disease is characterized by dying ganglion nerve cells in the retina, the light-sensitive tissue at the back of the eye that catches the images we see. Once these cells die, they are never replaced, which makes early detection of glaucoma critical.
Among the many different types of glaucoma, the most common is open-angle glaucoma, caused by clogging of the eyes' drainage canals in people who have a wide angle between the iris and cornea. Besides older age, risk factors include genetic predisposition, nearsightedness, higher eye pressure, high and low blood pressure, diabetes and hypothyroidism.
Detection
The lack of symptoms is a major reason why glaucoma is often not detected early. And the idea that glaucoma always has something to do with high eye pressure is a prime reason why diagnosis is often missed by eye specialists during regular eye exams. Although high eye pressure is a hallmark of a condition called angle-closure glaucoma, it is not necessarily present in the more common open angle glaucoma.
Annual eye exams are recommended for people who are over age 60 and anyone with a first-degree relative (parent, sibling or child) who has or had glaucoma. People younger than 60 should consider getting eye exams, including glaucoma screening, every two years.
To ensure that your exams are thorough enough to detect glaucoma, make sure that, besides having eye pressure measured, you receive a side vision test, which examines peripheral vision, or a visual field test, which examines both peripheral and central vision. The optic nerve head or optic disc (a part of the eye where ganglion cells enter the optic nerve) should also be examined by the eye specialist to evaluate the health of those ganglion cells.
Treatment
If glaucoma is detected, treatment can prevent further damage by restoring eye-fluid drainage and/or relieving eye pressure. This is accomplished by use of daily eye drops or a combination of eye drops and oral medication. Many different types of eye drops some known as prostaglandin analogs (such as Xalatan, Lumigan and Travatan Z)... some alpha agonists (such as Alphagan P)... and some carbonic anhydrase inhibitors (such as Trusopt)-are prescribed, depending on glaucoma symptoms that need to be managed. Laser eye surgery or traditional types of eye surgery that relieve pressure and correct blocked drainage ducts are options for people who don't get adequate relief from eye drops or who experience allergy or severe side effects from medications-but these people still may need to continue using some form of medication after surgery until eye pressure and drainage aright themselves.
Side effects of eye drops can include change in color of the iris and eyelid skin, stinging and burning of the eye, blurred vision and related problems. But most people who become lax about eye drop use don't do so because of side effects. They do so because they forget to use them, sabotaging their fight against glaucoma symptoms.
In a study in which we electronically monitored people who were using eye drops for glaucoma management, we discovered that, under the best of circumstances, patients were taking their eye drops only 70% of the time. Of course, eye drops can't help relieve glaucoma unless they are consistently used.
Helpful: Set up a reminder system. For example, set your cell-phone alarm to alert you when to use the drops.
As for alternative treatments for prevention of open-angle glaucoma beyond early detection and management, scientific evidence shows no association between glaucoma and a person's personal habits, such as diet, use of vitamins and supplements, alcohol consumption and caffeine intake. Altering these behaviors, unfortunately, will not decrease your chances of getting glaucoma or prevent it from getting worse. However, aerobic exercise (20 minutes four times a week) can increase blood flow and reduce eye pressure, which can keep glaucoma from worsening.
Where to get treatment
Optometrists can diagnose glaucoma and treat it with eye drops. Ophthalmologists can diagnose it and treat it with a wider range of therapies-eye drops as well as laser treatments and eye surgery. But whichever type of specialist you consult, make sure that he is up-to-date on how best to detect glaucoma during an eye exam. To find optometrists and ophthalmologists in your area who have specialized training in glaucoma diagnosis and treatment and have been given by glaucoma experts, visit the Glaucoma Research Foundation website at www.glaucoma.org.
