Imagine that, as you read this 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.
To arm you with the best advice on stopping glaucoma in its tracks, I spoke with a leading glaucoma specialist and researcher Harry A. Quigley, MD, director of the Glaucoma Center of Excellence at Johns Hopkins University’s Wilmer Eye Institute and author of Glaucoma: What Every Patient Should Know.
First off—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 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.
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, said Dr. Quigley. 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.
Dr. Quigley recommends annual eye exams for people who are over age 60 and urges anyone with a first-degree relative (parent, sibling or child) who has or had glaucoma to get annual exams, too. 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, said Dr. Quigley. 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.
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 eyedrops or a combination of eyedrops and oral medication. Many different types of eyedrops—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 eyedrops 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 eyedrops can include change in color of iris and eyelid skin, stinging and burning of the eye, blurred vision and related problems. But most people who become lax about eyedrop use don’t do so because of side effects. They do so because they forget to use them, sabotaging their fight against glaucoma symptoms.
“Although use of daily eyedrops is the first-line treatment for glaucoma, the sad truth is that people don’t remember to take their eyedrops even though they may claim to use them every day,” said Dr. Quigley. He and colleagues conducted a study in which they electronically monitored people who were using eyedrops for glaucoma management. They discovered that, under the best of circumstances, patients were taking their eyedrops only 70% of the time. Of course, eyedrops can’t help relieve glaucoma unless they are consistently used. Dr. Quigley’s advice to people using eyedrops is that they set up a reminder system. For example, a person could set his or her cell-phone alarm to alert them when to use the drops.
As for alternative treatments for prevention of open-angle glaucoma beyond early detection and management, Dr. Quigley said that the 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, in Dr. Quigley’s view. However, he told me that 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 eyedrops. Ophthalmologists can diagnose it and treat it with a wider range of therapies—eyedrops as well as laser treatments and eye surgery. But whichever type of specialist you consult, make sure that he or she 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 a seal of approval by glaucoma experts, Dr. Quigley recommends visiting the American Glaucoma Society Website.
Finally, Dr. Quigley told me that his book, Glaucoma: What Every Patient Should Know: A Guide from Dr. Harry Quigley, which is being sold through Amazon.com in Kindle and paperback formats, can be freely accessed online through the Wilmer Eye Institute. If you buy the book, though, know that proceeds of book sales will go to a great cause…glaucoma research.
Harry A. Quigley, MD, A. Edward Maumenee Professor of Ophthalmology and director, Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore.Date: November 17, 2014 Publication: Daily Health News