|
E-mail this page to a friend!
Alzheimer's, Dementia & Mental Health
Earliest Detection of Alzheimer's May Be Found in
the Eye
Optical test detects early molecular signs of the
disease before AD pathology is present in the brain
 October 3, 2006 – A new optical test can detect
early signs of Alzheimer's disease in the eye even before the evidence
appears in the brain. Lee Goldstein of Brigham and Women’s Hospital and
Harvard Medical School will present “proof of concept” evidence obtained
in tests with mice at next week's Frontiers in Optics, the annual
meeting of the Optical Society of America (OSA) in Rochester, N.Y.
| |
Related Stories |
|
| |
Earlier Detection of Alzheimer's Disease Made
Possible by New Discovery
Faster detection can lead to beneficial early
treatment
September 26, 2006 – Comparing the fight against Alzheimer's disease to
a boxing match, it appears that AD just took a blow to the body. It was
not intended as a knockout, just another punch to break down the
defenses.
Read more...
Study Finds Further Evidence of Rapid Weight Loss in
Senior Citizens Before Alzheimer's
It is still unclear
exactly why weight loss is associated with dementia
 September 11, 2006 – A new study joins a growing
list of research reports indicating there is some association between
Alzheimer's disease and rapid weight loss in senior citizens. (See other studies on this
subject in sidebar.)
Read more...
Senior Citizens Worried About Early Dementia May
Just Be Anemic
Study among elderly women finds even mild anemia
has impact
 September
13, 2006 – Senior citizens finding it difficult to think clearly may
jump to the conclusion they are experiencing the early signs of
dementia.
Read more...
Drinking Fruit, Vegetable Juices Lowers Alzheimer's
Risk 76 Percent in New Study
Another study pointing to health benefits of
polyphenols
September 1, 2006 - People who drank three or more
servings of fruit and vegetable juices per week had a 76 percent lower
risk of developing Alzheimer’s disease...
Read more...
Cell Activities that
Protect against Alzheimer's Protein Buildup Found
Findings may lead to new therapies for
Neurodegenerative Diseases such as Alzheimer's and Parkinson's
 August
11, 2006 – Yesterday there was news of research finding it is aging that
actually causes the brain to stop cleaning out the protein build-up that
causes Alzheimer's.
Read
more...
Aging is the Critical Factor Allowing Alzheimer's to
Develop
Aging process plays an active role, too, in
Parkinson’s and Huntington’s
August 10, 2006 –
Read more...
Read more
on
Alzheimer's, Dementia & Mental Health |
|
This dramatic new development in the technology
raises hopes for detecting the disease at its earliest stages and
slowing the progression of the disease to a crawl.
At the plenary talk, Goldstein will describe how
the tests can detect early molecular signs of the disease in the eye
even before Alzheimer’s pathology is present in the brain. Goldstein
envisions that the tests could become part of a suite of “universal
early screening technologies” that would be a routine part of an annual
physical exam for people starting in middle age.
With the tests, envisioned to be relatively
inexpensive, physicians would be able to monitor patients year to year
for any signs that the disease is present and progressing. The goal,
according to Goldstein, is to catch the disease early in its course when
treatment is likely to be most effective.
The technology may have additional value in
accelerating clinical testing of new emerging treatments for the
disease.
At last year’s annual OSA meeting, Goldstein
unveiled two laser-based eye tests that could detect unusual cataracts
composed of the amyloid beta protein, the same molecules that are the
hallmark of Alzheimer’s disease.
Previously, Goldstein and his colleagues had
discovered evidence that Alzheimer’s was not just a brain disease, but
rather a “systemic” one that manifests itself in the lens of the eye.
The amyloid beta proteins that form plaques in the brain and impair
cognitive function also build up near the edge of the lens, ultimately
forming an unusual “supranuclear” cataract that is very different from
more familiar, age-related cataracts.
Fortunately, Goldstein says, the only pathological
molecules that seem to form in this particular part of the lens are the
amyloid beta particles, tremendously simplifying the researcher’s task
of differentiating Alzheimer’s from other disease states involving the
lens. “Mother Nature dealt us a lucky hand here,” he says.
Both of the optical tests involve the use of a
low-intensity laser that very briefly is directed into the lens, shining
low-power light into the eye. The light is safe and barely visible to
the patient and does not provide any discomfort, Goldstein says.
In the first test, light enters the lens and
ricochets or “scatters” from tiny particles too small for the eye to
see. The “quasi-elastic” light scattering test can detect small clumps
of beta-amyloid particles in the lens.
The beta-amyloid proteins collect as aggregates in
the lens as small as tens to hundreds of nanometers in size. Small
increases in the size or number of these nanometer-scale particles
create large effects in light scattering that are detected and analyzed
by the technology, he says.
Recently, Goldstein and his colleagues have shown
in animal trials that this test can detect the particles that form the
unusual cataract associated with Alzheimer’s disease, even before they
coalesce into something that can be seen with the naked eye.
“We can pick this up in entirely clear lenses,”
Goldstein says. “This is exactly what we want to be doing.”
The second test uses eye drops that contain a
specially designed “ligand” that specifically binds to amyloid beta
proteins. When laser light from the instrument is directed into the
lens, the amyloid then emits a characteristic light signal that is
detected and analyzed by the technology. Goldstein emphasizes that these
are not imaging tests—the output of the technology is not a picture to
be read like a chest X-ray—but rather a “molecular diagnostic” that can
detect and analyze suspicious amyloid beta deposits in the lens.
Recently, Goldstein and his colleagues showed in
mice that they could pick up signs of the protein in the lens even
before the classic amyloid brain lesion of Alzheimer’s disease developed
in the brain.
|
 Half of all
people who reach age 85 will likely be affected by Alzheimer’s
disease, with the onset age usually around 75. |
This is vitally important, he says, as early
detection is the only way that physicians can effectively treat the
disease. In addition, detecting Alzheimer’s early through eye tests can
monitor the effectiveness of the many drugs being developed to slow the
condition.
Meanwhile, these techniques have been tested in a
Phase I trial in humans with phase III multicenter human clinical trials
slated for next year. In the end, the tests could cost less than $300
per test, he says.
As a potential early screening tool and
confirmatory diagnostic technology, this is the ballpark range for a
widely used test, he says. As no definitive test for diagnosing
Alzheimer’s currently exists, the tests may also help to differentiate
the earliest stages of Alzheimer’s from other neurodegenerative diseases
and normal changes in cognition associated with aging.
So the eyes may be more than a poet’s window to the
soul. They may also be a gateway to the brain and to effective early
treatment of a devastating brain disorder.
Notes:
The Alzheimer’s disease research of Goldstein and
his team is funded by the National Institutes of Health, American
Federation for Aging Research, Alzheimer’s Association, and the American
Health Assistance Foundation. Goldstein is a co-founder and scientific
consultant to Neuroptix Corporation, a Massachusetts-based diagnostic
biotechnology company that has licensed and is developing the technology
for clinical use.
Talk: “Optics Meets Alzheimer’s Disease: Seeing
the Way to a Cure,” Lee Goldstein, Harvard Medical School and Brigham
and Women’s Hospital, Frontiers in Optics Plenary Session, Monday, Oct.
9, 8 a.m.-12 p.m. More information is available at
http://www.osa.org/meetings/annual/program/plenary/.
Click to More Senior News on the
Front Page
Copyright: SeniorJournal.com |
