MACULAR DEGENARATION: The Downside of Living Longer

USA Today (Society for the Advancement of Education), Nov, 2000 by Eve Herold

"Usually, by the time patients learn what [the condition] is, they are shocked and disappointed to find out that nothing can be done to improve their vision."

"NOTHING COULD BE more emblematic of modern progress than the aging of the population. In the America of 1900, even then the most industrialized nation on Earth, the average life expectancy was 49. Today, according to the U.S. Department of Health and Human Services, the average American can expect to live to be 83. While few of us would turn down an extra 34 years of good food sunsets, invigorating vacations, and time with our loved ones, there is an increasing likelihood that our enjoyment of those years could be marred by disability. The very successes of science and medicine in this technological age have created a paradox--a longer life, but with more life-diminishing diseases.

After curing many of the illnesses that used to cut lives short, medicine is now playing catch-up to try to improve the lives of older people. Just to show how far we've come, even 50 years ago, the most common diseases of the elderly were not regarded as diseases at all, but as natural conditions of old age. Alzheimer's disease used to be blamed on "senility," and heart disease was considered inevitable. Diminished eyesight, sometimes even blindness, was another natural consequence attributed to the aging process.

Macular degeneration is not a normal part of aging. Age itself doesn't cause it, but it is by far the biggest risk factor. Most of the people who have the condition had never even heard of it until a doctor gave them the diagnosis, and that is usually when they started to develop major visual impairment because of it. Yet, the incidence of age-related macular degeneration (AMD) is increasing so rapidly that about 25% of adults over 60 are known to have it and about 4,000 new cases are diagnosed each week. As the baby boomers age, the incidence of AMD will skyrocket. By 2030, the estimated number of Americans who are severely impaired by it will jump from 1,700,000 to 6,300,000.

Macular degeneration is a condition that causes blindness in the center of the field of vision. Its victims live with constant frustration. Just going through their daily routine--from combing their hair to preparing a meal, reading the newspaper, or finding something they have dropped on the floor--is an uphill battle. As the disease progresses, seeing traffic signs and reading price tags in stores are out of the question. Their peripheral vision gives them a blurry idea of what is going on around them, but things they see "in the corner of their eye" either vanish or get lost in distortion the moment they try to focus on them. The things they look directly at are the very things they cannot see.

This is because AMD obliterates some of the most irreplaceable cells in the human body--the specialized light-sensitive ones at the center of the retina (called the macula) that produce central vision. Central vision refers to tar more than just the center of one's field of vision. It is the only part of our vision that gives us the sharp focus we need to read, drive, and recognize trees--practically everything we think of when we consider being able to see. Macular degeneration patients generally retain their peripheral vision, but this is tar more problematic than we might think. Most of us don't realize it, but our peripheral vision is fuzzy enough to be classified as legally blind. Thus, while most people with macular degeneration are not considered totally blind, they are blind in just about every way that counts.

Usually, by the time patients learn what AMD is, they are shocked and disappointed to find out that nothing can be done to improve their vision. The disease can't be cured, and the vision lost to it cannot be corrected with surgery, glasses, or contact lenses. There are limited treatments that may benefit a small number of patients, but, for the most part, today's victims must !earn to live with it. Tomorrow's victims may have more hope, but that depends on the success of research, and there are many scientific problems to unravel before an actual cure can be claimed.

There are two forms of macular degeneration, but many doctors see the condition as "two diseases in one." The first form, called "dry" AMD, slowly and insidiously destroys the cells of the macula so that central vision fades away over time. For reasons that no one understands, the cells simply degenerate and die. Over a period of years, the effect can be devastating. About 90% of macular degeneration patients have this form of the disease.

The remaining 10% of patients have "wet" macular degeneration, which is considered the more severe stage or form of the disease. Wet macular degeneration develops when new, abnormal blood vessels start to grow in a layer of tissue just beneath the retina, a condition called neovascularization. These tiny, fragile vessels are subject to a stroke-like condition in which they almost inevitably rupture and bleed. Blood and scar tissue displace and kill the macular cells, effectively blanking out that part of the visual field. Major vision loss can occur quickly, developing over a period of days or weeks.