Could be symptoms of age-related macular degeneration

Q. I’m 70, and I’m starting to see a blurred area in the middle of my vision. Any ideas?

Have this checked immediately by an eye care practitioner. What you describe is a symptom of age-related macular degeneration (AMD), a leading cause of vision loss in Americans 60 years of age and older.

The macula is at the center of the retina in the back of your eye. The retina transmits light from the eye to the brain. The macula allows us to perform tasks that require central vision such as reading and driving.

In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. It comes in two forms—wet and dry.

Wet AMD occurs when blood vessels behind the retina start to leak and raise the macula. An early symptom of wet AMD is straight lines that appear wavy. Wet AMD is considered to be advanced AMD and is more severe than the dry form. However, dry AMD can turn into wet AMD at any time.

Dry AMD occurs when macular cells break down, gradually blurring central vision in the affected eye. Central vision in the affected eye can be lost. Dry AMD generally affects both eyes, but vision can be lost in one eye.

The risk of getting AMD increases with age. Other risk factors include smoking, obesity, race (whites are at higher risk), a family history of AMD, and gender (women are at higher risk).

AMD is detected through a comprehensive eye exam that includes a visual acuity test, a dilated eye exam and tonometry. Visual acuity is measured with an eye chart test. In the dilated eye exam, drops are placed in your eyes to enlarge the pupils. Then, a magnifying lens is used to examine your retina. Tonometry measures the pressure inside the eye.

You may also be asked to look at an Amsler grid. With one eye, you will stare at a black dot in the center of the grid. You may notice that the straight lines in the pattern appear wavy or are missing. These may be signs of AMD.

Other tests that may be done include:

• Using special dye and camera to look at blood flow in the retina (fluorescein angiogram).

• Taking a photo of the inner lining of the eye (fundus photography).

• Using light waves to view the retina (optical coherence tomography).

Once dry AMD is in the advanced stage, no treatment can prevent vision loss. However, treatment can delay and possibly prevent AMD from progressing to the advanced stage. Some vitamins and minerals may reduce the risk of developing advanced AMD.

Wet AMD can be treated with surgery, therapy and injections into the eye. None of these treatments is a cure for wet AMD. Each treatment may slow the rate of vision decline, but the disease may progress anyway.

The U.S. Food and Drug Administration has approved the Implantable Miniature Telescope (IMT) to improve vision in some patients with end-stage, age-related macular degeneration.

Surgically implanted in one eye, the IMT is a small telescope that replaces the natural lens and provides an image that has been magnified.

If you have lost some sight from AMD, don't be afraid to use your eyes for reading, watching TV and other routine activities. Normal use of your eyes will not damage your vision further.

Fred Cicetti is a freelance writer who specializes in health. He has been writing professionally since 1963. Before he began freelancing, he was a reporter and columnist for three daily newspapers in New Jersey. If you would like to ask a question, write to fred@healthygeezer.com.