Understanding macular degeneration

macular degeneration, vision, diagnosisMacular degeneration is getting better known as more people, particularly older Americans, are being diagnosed with it. But exactly what is macular degeneration, and how can it be avoided?

Age-related macular degeneration, or AMD, destroys a person’s sharp, central vision, which is needed to see objects clearly and perform everyday tasks such as reading and driving. It is a leading cause of vision loss, and it now affects at least 5 percent of people over 65 in the United States, according to the National Health Interview Survey.

There are two kinds of AMD:

• Dry AMD. This is the most common type of the problem. An early sign is blurred vision, which may go away in bright light. You may also see a small (but growing) blind spot in your field of vision. Sometimes only one eye may be affected, and the other one will compensate, making symptoms harder to spot.

• Wet AMD. An early symptom here is when straight lines appear crooked. That’s because blood vessels are leaking, and that fluid is gathering and lifting the macula cells. You may also develop a small blind spot with this type of AMD.

Who gets AMD? Research indicates that around half of the cases diagnosed are genetically related. Age also ups the risk, especially with whites and women. Prevention data is still being collected, but it appears that nutrients like zinc, leutein, and vitamins A, C, and E may lower the risk of AMD and also slow down its progression. On the flip side, smoking greatly increases the risk of developing AMD.

If you are having any of these symptoms, or if there is a history of AMD in your family, it’s time to see your eye doctor. This is especially true if you’re over 40 and haven’t had an eye exam in more than two years, or if you’re over 50 and haven’t had your eyes checked in more than a year. Your eye doctor will run some special tests, including taking special photographs with optical coherence tomography (OCT) to get an accurate diagnosis and then chart a course of treatment.

There is no cure for AMD yet, but there are a lot of treatment options for wet AMD that slow it down. Those include the injections of drugs that reduce blood vessel growth, as well as photodynamic therapy and thermal laser treatments. There’s not as much to offer for dry AMD right now, but there are new drugs in clinical trials and hopefully they will be on the market soon.