Eyesight, an Insight - Insight - Diseases

ARMD, age-related macular degeneration is a common eye disease associated with aging that gradually destroys sharp, central vision. Central vision is needed for seeing objects clearly and for common daily tasks such as reading and driving. In some people, ARMD advances so slowly that it will have little effect on their vision as they age. But in others, the disease progresses faster and may lead to a loss of vision in one or both eyes.

Macular degeneration is more common in older people, and it affects whites more than blacks. Most cases of macular degeneration are age related, though some cases are side effects of toxic drugs such as Aralen (chloroquine, an anti-malarial drug) or phenothiazine.

Phenothiazine is a class of anti-psychotic drugs, including Thorazine (chlorpromazine, which is also used to treat nausea and vomiting, and intractable hiccups), Mellaril (thioridazine), Prolixin (fluphenazine), Trilafon (perphenazine) and Stelazine (trifluoperazine). Although causes are still unknown, the disease tends to run in families.

The retina is a paper-thin tissue that lines the back of the eye and sends visual signals to the brain. In the middle of the retina is a tiny area called the macula. The macula is made up of millions of light-sensing cells that help to produce central vision.

Dry ARMD: Ninety percent of all people with ARMD have this type. Scientists are still not sure what causes dry ARMD. Studies suggest that an area of the retina becomes diseased, leading to the slow breakdown of the light-sensing cells in the macula and a gradual loss of central vision.
Wet ARMD: Although only 10 percent of all people with ARMD have this type, it accounts for 90 percent of all blindness from the disease. As dry ARMD worsens, new blood vessels may begin to grow and cause "wet" ARMD. Because these new blood vessels tend to be very fragile, they will often leak blood and fluid under the macula. This causes rapid damage to the macula that can lead to the loss of central vision in a short period of time.

The greatest risk factor is age. Although ARMD may occur during middle age, studies show that people over age 60 are clearly at greater risk than other age groups. For instance, a large study found that people in middle-age have about a 2 percent risk of getting ARMD, but this risk increased to nearly 30 percent in those over age 75.

Gender: -Women tend to be at greater risk for ARMD than men.
Race: Whites are much more likely to lose vision from ARMD than Blacks.
Smoking: Smoking may increase the risk of ARMD.
Family History: Those with immediate family members who have ARMD are at a higher risk of developing the disease.

Both dry and wet ARMD cause no pain. The most common early sign of dry ARMD is blurred vision. As fewer cells in the macula are able to function, people will see details less clearly in front of them, such as faces or words in a book.

Often this blurred vision will go away in brighter light. If the loss of these light-sensing cells becomes great, people may see a small-but growing-blind spot in the middle of their field of vision. The classic early symptom of wet ARMD is that straight lines appear crooked. This results when fluid from the leaking blood vessels gathers and lifts the macula, distorting vision. A small blind spot may also appear in wet ARMD, resulting in loss of one's central vision.

Your eye care professional may suspect ARMD if you are over age 60 and have had recent changes in your central vision. To look for signs of the disease, he or she will use eye drops to dilate, or enlarge, your pupils. Dilating the pupils allows your eye care professional to view the back of the eye better. You may also be asked to view an Amsler grid, a pattern that looks like a checkerboard. Early changes in your central vision will cause the grid to appear distorted, a sign of ARMD.

No treatment now exists for dry ARMD. It has been suggested that taking certain extra vitamins and minerals may slow the progress of the disease. But this treatment needs much more research before scientists can know for sure if it's helpful.

Eye care professionals can treat some cases of wet ARMD with laser surgery. This treatment involves aiming a strong light beam onto the new blood vessels to destroy them. Laser surgery is done in a doctor's office or in an eye clinic and lasts a short period of time. Although a person may go home the same day, he or she will need to return for follow-up exams.

Source(s): All above information & images are based on: an article at National Eye Institute and on an article written by Gretchyn Bailey, allaboutvision.com. All rights reserved by respective owners.

Disclaimer: Any information displayed here is just for educational purposes, and may not be taken as an expert advice and should not be applied in life without consulting your eye doctor/specialist. We here by take no responsiblity of the accuracy of the above content as they have been taken from various sources.