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Among revolutions, this may be a quiet one, yet it's dramatically
changing the lives of people with one of the most heartbreaking disorders
associated with aging—failing eyesight.
After years of frustration, scientists are developing treatments that can
slow the inevitable descent into darkness caused by "wet" macular
degeneration, an eye disease that strikes 200,000 Americans a year. Macugen, a
drug on the market since January, may in some cases reverse vision loss. And
clinical trials are showing that a second drug, Lucentis, which could be
available within 18 months, may be even more effective.
"For the first time we have a treatment where visual acuity is actually
improved," said Robert D'Amato, M.D., an ophthalmologist with Harvard
Medical School and Children's Hospital in Boston. "People can actually
see better than they could when the [Macugen] trial started."
Macular degeneration is the most common cause of blindness after age 50. The
dry form of the disease occurs when pigment cells beneath the retina
deteriorate, diminishing eyesight. The more serious but less common wet form
accounts for only about 10 percent of the more than 1.75 million cases of
age-related macular degeneration in the United States.
Wet macular degeneration is caused by the abnormal growth of leaky blood
vessels in the retina, the eye's light-sensing organ. The new drugs stop
the action of VEGF, a natural substance that stimulates such growth and
gradually damages the macula, the central area of the retina that allows
fine-detail vision needed for reading or sewing.
Most patients are left with only peripheral vision, and many can no longer
recognize faces, read signs or do ordinary chores.
"I went from being quite dependent on my husband to being able to drive
legally" as a result of Macugen treatments, says Charlotte Warner, 83, of
Strongsville, Ohio. When she joined the drug trial three years ago, vision in
her right eye was gone and her left eye was deteriorating.
"I'm an avid reader, but I was having to use a magnifying glass
even to see the big print," she adds.
"I started to improve gradually," she says, "and after three
doses I was elated" because some vision was returning. Now the vision in
her left eye is 20/25, and she can read and watch TV.
Macugen, made by Eyetech Pharmaceuticals Inc. in New York, won approval from
the federal Food and Drug Administration last year. Genentech Inc., of South
San Francisco, the manufacturer of Lucentis, reported in July that monthly
injections of the drug benefited most of the 716 patients in a one-year
clinical trial, with 34 percent of those who got a higher dose (5 milligrams
instead of 3) reporting improved vision: They were able to read smaller
type—three lines lower—on an eye chart.
Ironically, the discoveries leading to treatments for eye diseases came from
cancer research, not eye research. Lucentis, in fact, is an altered version of
Avastin, a colon cancer drug that some eye doctors use to treat wet macular
degeneration. Philip Rosenfeld, M.D., of the University of Miami Bascom Palmer
Eye Institute in Florida, says of his experiments with Avastin, "I'm
seeing in these patients something I've never seen before: they are getting
better. This is a 'Gee whiz!' 'Wow!' experience."
The medication drains fluid from retinal tissue, he says, and returns the
retina to its normal shape. He says its benefit seems to last longer than that
of Macugen or Lucentis, usually up to six months or more in two-thirds of his
patients. Rosenfeld hopes to start a large clinical trial with Avastin soon and
expects to report current results at a scientific meeting in February.
Until now, the most effective treatments have used laser beams to burn leaky
blood vessels in the retina, preserving sight temporarily. But eyesight does
not improve, and over time vision loss continues.
Macugen and Lucentis are injected directly into the eye, an off-putting
notion to some. But side effects—inflammation, eye irritation, reduced
clarity and discomfort after treatment—are minimal, experienced by less
than 1 percent of patients.
Some doctors have expressed concern about price, worrying that Lucentis may
cost as much as $4,000 a dose. But a Genentech representative, Dawn Kalmar,
said a price has not been set. It isn't known yet if Medicare and insurers
will cover the drug.
Macugen injections, given every six weeks, cost $995 a dose, and are covered
by Medicare and some insurance companies.
The drugmakers are setting up programs to help people on limited incomes pay
for the medications.
The possibility of curbing eye damage by blocking VEGF was discovered by
Anthony Adamis, M.D., vice president and chief scientific officer at Eyetech,
and his fellow ophthalmologist Joan Miller, M.D., of the Massachusetts Eye and
Ear Infirmary in Boston. Such developments are propelling eye research into an
exciting new phase. Adamis likens it to the Sputnik era, at the dawn of the
space age. "We're right at the beginning."
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