When it comes to glaucoma, family ties might not be a good thing. Open-angle glaucoma, which accounts for 90% of glaucoma cases, has a familial component and, therefore, is in part due to heredity. However, blood relatives of people with glaucoma often don't realize that they, too, are at risk. If you or someone in your family has glaucoma, you'll want to read and share this Special Report – it could save a loved one's eyesight.
According to researchers at Johns Hopkins, approximately 150,000 family members of people with glaucoma also have the disease but have not been diagnosed. That's not surprising, given the results of a recent Johns Hopkins study -- the first to focus on family members of people who have glaucoma.
The researchers found that even highly educated people with glaucoma and their similarly educated family members are sometimes not aware that their family is at an increased risk for glaucoma. The study, called the Help the Family Glaucoma Project, began in 2004, when researchers interviewed 102 people with glaucoma and 300 family members, the majority of whom had a college education or higher.
In both groups, about 80% realized that glaucoma is hereditary, but one fifth (20%) did not -- a surprising finding, given that family members of those with the disease have 10 times the risk of the normal population. Equally disturbing, about one third of the people in the study had not instructed their family members to have an eye exam.
These findings are crucial because glaucoma is largely without obvious symptoms until the disease is well advanced. Yet when glaucoma, which gradually destroys the fibers in the optic nerve, is caught early, eye drops, laser treatment, or surgery can delay its progression by lowering the elevated intraocular pressure (IOP) that ultimately damages the optic nerve.
Johns Hopkins researchers believe the lack of knowledge about glaucoma risk factors, including heredity, stems from lack of patient education. Eye doctors, they say, have to do more than ask about family history. They need to say directly, "If you have glaucoma, your siblings and your children may have it, and they need to be seen by an eye doctor and undergo a dilated pupil examination of the optic nerve and a visual field test."
People who don't have elevated eye pressure and don't know of any relatives with glaucoma may still be at risk for the condition. Anyone who is age 40 or older, especially if he or she is black or Hispanic, is near-sighted, or is taking corticosteroids, should get an eye exam at least once a year to find out if his or her eyes show any evidence of glaucoma.
Signs of Trouble -- Although you're not likely to notice any symptoms of glaucoma until the disease has progressed significantly, an eye doctor can identify glaucoma before significant damage occurs. During an eye exam, the eye doctor is looking for three signs that suggest glaucoma:
- A shift in the cup-disc ratio. This is the size of the yellow center of the optic nerve relative to the normally thick orange rim of optic fibers that surround it. These fibers are destroyed by glaucoma.
- Visual field irregularities. Your visual field is the range of vision off to the sides while your eyes are focused straight ahead. If your doctor sees a suspicious change in the optic nerve or if you have a family history of glaucoma, he or she will likely obtain a visual field test. Usually the change starts in one spot of the visual field and slowly expands. However, the loss of visual field is so slow that your doctor may be able to identify changes on the test before you become aware of it.
- Elevated pressure within the eye. The eye doctor will also measure your intraocular pressure. But half of those with open-angle glaucoma (the most typical kind) have eye pressures in the normal range, so simply having a "normal" eye pressure is no assurance that glaucoma is not present.
Share the News. An important step you can take if you are diagnosed with glaucoma, besides adhering to treatment, is to alert your family members. A number of vision organizations offer free examinations for those who are both uninsured and at risk. An excellent resource is the Glaucoma Eye Care Program, sponsored by Eye Care America. You can find more information by going to www.eyecareamerica.org or calling 800-391-EYES (3937).
Remember, if you have glaucoma, the next time you call or send an email to your sibling or child, mention your diagnosis -- and explain that they have a one in three chance of having it during their lives, and that it is a preventable cause of blindness. If you have an upcoming family reunion, take some educational materials with you and spread the word there.
