Sign up for email updates
Bookstore

Arthritis

Back Pain & Osteoporosis
Coronary Heart Disease
Depression & Anxiety
Diabetes
Digestive Disorders
Heart Attack Prevention
Hypertension & Stroke
Lung Disorders
Memory
Nutrition & Weight Control
Prostate Disorders
Vision


Vision

Library

Age-related Macular Degeneration

Symptoms

Increasingly blurred central vision.

Haziness, grayness, or blank spots in the central field of vision.

Visual distortion: Straight lines appear bent; objects may appear smaller than in actuality.

Dulled color perception.

Difficulty reading or doing close work.

When To Call Your Doctor

See an ophthalmologist if you have blurred or distorted vision.

A simple home test (the Amsler grid) can help monitor visual changes. Any worsening of vision warrants an immediate visit to an ophthalmologist.


What Is It?

The macula is the central and most sensitive portion of the retina, the layer of tissue in the back of the eye that contains the light-receptive nerve cells essential for sight. For some people in their 50s, the macula begins to break down to some extent, resulting in the condition known as age-related macular degeneration (AMD). In AMD, central vision and the ability to distinguish fine detail become increasingly impaired, but peripheral vision remains unaffected. If macular function is lost completely, activities such as reading become impossible.

There are two forms of AMD: non-neovascular (also known as nonexudative, atrophic, or dry) and neovascular (exudative or wet). About 90 percent of those with AMD have the non-neovascular form, which—although irreversible and essentially untreatable—tends to progress slowly and may stabilize so that most patients experience no serious vision loss. In neovascular AMD, however, fine blood vessels at the back of the eye proliferate and begin to leak or exude fluid, possibly scarring the macula and resulting in permanent central vision loss within days or weeks. Neovascular AMD may develop suddenly in patients with non-neovascular AMD. Both forms are painless and most often affect one eye at a time. AMD is the leading cause of severe and irreversible vision loss in older Americans.

What Causes It?

The cause is unknown, although aging is clearly a risk factor. Some evidence of AMD can be detected in approximately one quarter of all people over the age of 65 and in one third of those over age 80.

Other risk factors include hyperopia (farsightedness), cigarette smoking, light-colored eyes, and a family history of AMD. High blood pressure, lifetime sunlight exposure, dietary factors, and genetic susceptibility may increase the risk of neovascular AMD.

Prevention

There is no known way to prevent AMD. Presumably, avoidance of smoking, treatment of hypertension, and minimal sun exposure (wearing sunglasses and a hat with a wide brim) might help.

Diagnosis

Eye examination by an ophthalmologist is needed.

Neovascular AMD is confirmed with fluorescein angiography (injection of a special dye into the bloodstream to allow clear photographic images of the blood vessels in the eye to be taken).

How To Treat It

There are no ways to arrest or reverse the course of non-neovascular AMD. A research study is testing the use of vitamin and mineral supplements as a treatment. Retinal cell transplants do not yet work, but are being tested.

People with non-neovascular AMD should be monitored for the onset of neovascular AMD. In the meantime, low-vision optical aids may be useful, including: high-power reading glasses; a small telescope mounted on one lens of your eyeglasses; a pocket telescope for reading street signs; and a closed-circuit television hookup that can magnify a written page as much as 60 times and display the image on a television screen.

If detected early enough, neovascular AMD can often be treated with laser surgery to destroy the new leaking blood vessels. Such surgery should be performed only by an ophthalmologist with special training and experience in the procedure.

New treatments being tested include new lasers, surgery to remove or move abnormal vessels, and new drugs that may control new vessel growth.

Careful follow-up is essential for all AMD patients.

 

From Johns Hopkins Symptoms and Remedies, the complete home medical reference. You can order this book now on our secure server.

 

 


 


Buy now

2005
WHITE PAPERS
Vision

The vision White Paper from The Johns Hopkins White Papers series is an annual, in-depth report written by Hopkins physicians.


Buy now
Johns Hopkins Symptoms and Remedies
An easy-to-use reference work that can help you pinpoint the cause of hundreds of symptoms, from abdominal pain to skin rash to swollen glands.

 

    Contact us 
    © 2005 Medletter Associates, Inc.