What is Macular degeneration?

Macular degeneration

What is macular degeneration?

If you are over 60, and your eyesight is getting patchy and blurred, you could have macular degeneration. People with macular degeneration find it harder to read, recognize people's faces, or make out fine detail.

The full name for macular degeneration in older people is age-related macular degeneration. It's also called AMD for short. Macular degeneration can affect younger people, but this is rare. It can also be caused by injury to the eye,

infection
You get an infection when viruses, bacteria, fungi or other tiny organisms get into your body. These bugs are so tiny that you can't see them without a microscope. For example, an infection in your airways causes the common cold. And an infection in your skin can cause rashes such as athlete's foot.

infections, and

diabetes
Diabetes is a condition that causes too much sugar to circulate in your blood. It happens when your body stops making a hormone called insulin (type 1 diabetes) or when insulin stops working (type 2 diabetes).

diabetes (when it's called diabetic retinopathy). Here we deal with the disease that affects older people.

The macula is part of your retina, the lining inside your eye that captures the images you see and sends them to your brain.

The macula is a part of your eye that helps you see things in fine detail.

The macula is a tiny area in the middle of the retina. It helps you see the fine detail of objects right ahead.

But sometimes the cells in the macula get damaged and no longer work properly. When this happens it's called macular degeneration. Eventually things in the middle of your vision may look blurred and distorted.

There are two stages of AMD: early and late.

Early AMD

In early AMD, fluffy white patches form in and around your macula. Doctors call these drusen.

The patches don't affect your eyesight, but your doctor or optician can see them during an eye exam.

Late AMD

In late AMD, your eyesight is affected. There are two types of late AMD: dry and wet.

Dry AMD is more common. It affects more than 8 in 10 people who get AMD.

Source:
Bressler SB, Bressler NM, Fine SL.
Age-related macular degeneration.
Survey of Ophthalmology. 1988; 32: 375-413.

¹ Dry AMD progresses slowly. The fluffy white patches in the eye can gradually get bigger and join together. And the cells in the macula die. Dry AMD usually affects both your eyes. But the sight in one eye may get worse, while the other eye remains the same. You may get wet AMD.
Wet AMD affects between 1 in 10 and 2 in 10 people who get AMD. It causes more rapid damage and serious sight problems than dry AMD. In wet AMD, besides the cells in the macula dying, tiny new blood vessels form at the back of your eye.

Source:
Gottlieb J L.
Age related macular degeneration.
Journal of the American Medical Association. 2002; 288: 2233-2236.

² The blood vessels leak blood and fluid into your eye and damage your sight even more.

Why me?

We don't know why the macula sometimes stops working well as you get older. But a few things can increase the chances of this happening. You're more likely to get problems with your macula:

Source:
Evans JR.
Risk factors for age-related macular degeneration.
Progress in Retinal and Eye Research. 2001; 20: 227-253.

Source:
Pieramici DJ, Bressler SB.
Age-related macular degeneration and risk factors for the development of choroidal neovascularization in the fellow eye.
Current Opinion in Ophthalmology. 1998; 9: 38-46.

⁴

Source:
Smith W, Assink J, Klein R, et al.
Risk factors for age-related macular degeneration: pooled findings from three continents.
Ophthalmology. 2001; 108: 697-704.

⁵

Source:
Schmidt S, Hauser MA, Scott WK, et al.
Cigarette smoking strongly modifies the association of LOC387715 and age-related macular degeneration.
American Journal of Human Genetics. 2006; 78: 852-864.

⁶

If you smoke
If you have

high blood pressure
Your blood pressure is considered to be high when it is above the accepted normal range. The usual limit for normal blood pressure is 140/90. If either the first (systolic) number is above 140 or the lower (diastolic) number is above 90, a person is considered to have high blood pressure. Doctors sometimes call high blood pressure "hypertension."

high blood pressure
If someone in your family has macular degeneration.

Some experts think macular degeneration is more common in women than in men. But we don't know for certain.

Sources for the information on this page:

Bressler SB, Bressler NM, Fine SL.Age-related macular degeneration.Survey of Ophthalmology. 1988; 32: 375-413.

Gottlieb J L.Age related macular degeneration.Journal of the American Medical Association. 2002; 288: 2233-2236.

Evans JR.Risk factors for age-related macular degeneration.Progress in Retinal and Eye Research. 2001; 20: 227-253.

Pieramici DJ, Bressler SB.Age-related macular degeneration and risk factors for the development of choroidal neovascularization in the fellow eye.Current Opinion in Ophthalmology. 1998; 9: 38-46.

Smith W, Assink J, Klein R, et al.Risk factors for age-related macular degeneration: pooled findings from three continents.Ophthalmology. 2001; 108: 697-704.

Schmidt S, Hauser MA, Scott WK, et al.Cigarette smoking strongly modifies the association of LOC387715 and age-related macular degeneration.American Journal of Human Genetics. 2006; 78: 852-864.

This information was last updated on Oct 15, 2009

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment.
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