> > > New infromation is marked with an asterisk * < < <
Depending upon the advancement of AMD and CNV various types of surgery and drug administrations are possible. Although there is no wonder cure for the disease, there are many fine ophthalmologic groups working on the causes and control of AMD. Research is the key to future AMD advancements. I shall try to keep this page up-to-date for you.
A report in the Journal of the American Medical Association confirmed that cigarette smoking increases ones risk of developing AMD by 2.5 times. Unfortunately the increased risk persists even after 15 years of quitting. Along with all of the other health related ailments caused by smoking the message is even clearer . . . . BUTT OUT NOW !
Dr.David Wong an eye surgeon at the Royal Liverpool University Hospital in northwest England has received extensive press coverage about his recent surgical procedure on a 70 year of man in which he manipulated the retina by pulling an area of it to one side and tucking it under to provide a new undamaged retinal surface area over the fovia. Although this procedure is new, it does not halt the progression of the disease and is not a cure. The procedure is still under refinement in both Germany and the United States. Dr Eugene de Juan a professor at the Wilmer Eye Institute is also performing this experimental procedure.
Interferon-alfa-2a is a very expensive drug with fairly harsh side effects that has been studied in many international centers. The drug affects the patterns and nature of capillary division when the capillaries are actively growing and dividing. A 45 center world-wide study reported that this avenue of research does not show much promise as a useful treatment for AMD.The latest concensus is that Interferon alfa-2A provides no benefits as a treatment for choroidal neovascularization secondary to ARMD and may be associated with poorer visual outcome at certain stages.
To be effective, cortisone has to be administered in sufficient quantity to affect the back of the eye and it has serious side effects if given in high doses. Recently methods of injecting cortisone directly into the eye have been developed and this is a significant breakthrough. Studies are still in progress but it looks very promising.
There have been a few newsgroup postings concerning wine comsumption and the reduced risk of developing AMD. The results of a five year study from the National Health Nutrition and Examination Survey(NHANES-1) indicated that 7% of those over age 65 will develop AMD if they do not consume 2-12 glasses of red or white wine per year. On the other hand, only 4% will develop the condition if they drink less than one glass of wine per month. Heart disease and AMD share many risk factors and aong them is the tendency of platelets to accumulate along blood vessel walls. Wine has high phenolic content and because phenols are antioxidants, they play a role in reducing platelet formation along blood vessel walls. Beer and liquor has less phenols than wine by the way. Caution is advised due to the other risks associated with alcohol comsumption, namely drug interactions and reduced motor skills often resulting in injury or accident.
This is the drug that made headlines 34 years ago when it was found to be cause of approximately 12,000 birth deformities around the world. But today, researchers at the Scheie Eye Institute in Philadelphia, the Massachusetts Eye and Ear Hospital in Boston and the Mt. Sinai Medical Campus in Cleveland are researching thalidomide drugs that are showing great promise in experimental settings and pilot trials. The drug has the ability to inhibit the formation of blood vessels (angiogenisis) which may make it useful for halting AMD vision loss.
New research is underway by Dr. Lois E.H. Smith an assistant professor of ophthalmology
at
The use of shark cartilage for the treatment of cancer stems from the fact
that it an anti-angiogenic substance (it inhibits the growth of new blood
vessels). Excessive vascularization of the eye should respond to anti-angiogenic
treatment mechanisms although no definitive research is available at this
time concerning the use of shark cartilage.
Applicable only to wet type AMD with associated SRNV (Sub-Retinal Neo-Vascularization), specialized lasers are focused on the blood vessels growing beneath the retina and cause the vessels to burn and scar (cauterization), thus sealing off the flow of leaking blood. A badly damaged macula in the advance stages of AMD will not benefit from laser treatments.
Using a high-speed scanning pulsed laser to acquire rapid sequences of images
of the blood vessels underlying the retina, doctors at the Glaser Murphy Retina Treatment Centre have developed
a new technique of identifying individual feeder vessels which can then
be accurately targeted for micro-laser coagulation. This proceedure results
in higher prcision laser targeting treatments and reduces the amount of
unnecessary damage to surrounding healthy retinal tissue.
Indocyanine green dye is being used for dye assisted laser photocoagulation to offer a better guide for pinpointing offending neovascularization beneath the macula. The dye targets and sensitizes the vessels to help focus laser energy used in some types of eye surgery.
In the realm of future bionics I read an article recently about a team of researchers
who are experimenting with an intraocular implant of a lens and telescope
combination. Their tests with cadaver eyes have shown some promise and
the future for AMD sufferers may be in the form of a "inside-the-eye"
telescopic lens. Research however far fetched
may some day provide viable solutions, so don't laugh too hard, my friend.
New techniques for ultra fine submacular surgery are being developed by various institutions including the Eye Institute of West Florida and the Center for Macular Degeneration at the University Hospital - New Jersey Medical Clinic. Removal of tiny blood vessels requires unique approaches and new surgical instrumentation.
A light activated drug is injected into the bloodstream which has the ability to concentrate
in areas of neovascularization. A low-power non-thermal red laser is shined
into the eye where it causes a degredation of the blood vessels involved
in the neovascularization process (sort of like a dissolving reaction).
Miravant
in Santa Barbara,CA will start Phase 3 testing in November this year with
its drug PURLYTIN (SnET2, tin ethyl etiopurpurin). QLT Phototherapeutics in British Columbia, Canada
with its partner Ciba Vision, Atlanta, GA are presently in Phase 3 trials
with its drug VERTEPORFIN (BPD, a liposomal benzoporphyrin derivative).
Unlike confluent laser photocoagulation, which causes concurrent damage
to other healthy areas of the retina, photodynamic therapy is very selective
and its low-power minimizes the risk to surrounding healthy macular tissue.
Agouron
Pharmaceuticals Inc, in La Jolla, CA is investigating
the use of a drug called AG3340 as a therapy for AMD. The synthesized drug
was designed to fit into the receptor sites on the surface of cell membranes
where the biochemical reaction allowing the development of the blood vessels
occurs, thus inhibiting a family of enzymes known as matrix metalloproteases.
In other words, it stops the development of new blood vessels. Trials are
presently underway.
Monkey studies have shown promise for a technique which involves removing damaged retinal pigment epitherial (RPE) cells. The natural regeneration process of the host body re-grows normal cells as part of the healing process. Further studies are underway.
Golfer Sam Snead experienced significant improvement in one of his eyes after treatments by one of the research partners of
the Macular Degeneration Foundation. Currently undergoing clinical analysis,
microcurrent stimulation therapy seems to show some promise, especially
those with the DRY type of ARMD. Further information is available from
Dr. Damon
P. Millar II who specializes in this treatment.
The green light of an argon laser when used at low energy levels can be used to heat rather than vaporize tissues, sort of like a welder. The National Eye Institute hopes this treatment will offer 50% or better chance of slowing or stopping severe vision loss from AMD.
The technology employs a series of therapeutic apheresis (blood filtration
and purification) procedures which remove toxic waste material (such as
macro-proteins, lipids, cholesterol, and others) that accumulate over time
in the blood and certain tissues, which are believed to cause the symptoms
of many common eye diseases including AMD. The company, Occulogix Corp, has stated that while the results are promising, they are from a pilot study and until a definitive trial has been established with results documented, they cannot conclusively state whether the treatment is safe and/or effective. From 4 to 10 treatments at about $2,000 per session are required.
Increased consumption of dark green, leafy vegetables (such as spinach and collard greens) seems to indicate that AMD can be delayed many years. LUTEIN and ZEAXANTHIN carotenoids which are primarily found in dark green leafy vegetables are among the best risk reducing naturally occurring substances for AMD. Kale, collard greens, and spinach are the best known natural sources of these carotenoids
A German team of doctors has reported their clinical
experience with a new type of ophthalmoscope which simultaneously captures
fluoresein and indocyanine-green angiographic images through the use of
a dual dye injection. The method is superior to individual angiography
since it produces simultaneous digital image frames, requires only one
injection and is not associated with additional side effects.
There is some evidence that certain
dietary components known as antioxidants can help prevent macular degeneration.
Many doctors believe that Vitamins A, C and E and dietary carotenoids,
are essential for ocular wellness. These nutrients can inhibit oxidative
reactions. Some minerals, such as zinc, copper and selenium, may also be
involved. To learn more about these supplements visit Preventions
Magazines 'Healthy Ideas. It should be noted that the usage
of vitamin and mineral supplements should be started only under the supervision
of a qualified physician.
Although there is no proof that zinc taken orally has any significant effect on AMD it is claimed to have stabilized some cases of AMD. The inconclusive results are diminished by the fact that too much zinc is bad for your overall health. Limits on the amount of zinc in vitamin supplements is now in place. The major dietary source of zinc are shellfish (especially oysters), meat, liver, poultry, eggs, and dairy products.
Researchers at the Erasmus University Medical School in Rotterdam, The Netherlands
produced a paper in 1995, about the link between AMD and atherosclerosis.
Recently a study at the University of Wisconsin at Madison, WI failed to find a
strong relationship between the two diseases. ( Editors Note: Here again
we find that more research and long-term analysis is needed.
Studies and reports are surfacing that indicate
a link between certain types of light energy and the onset of AMD. More
UV rays from sunlight reach the retina in blue-eyed patients, probably
because of the lower pigment density in the eye. NoIR
Medical Technologies manufactures and sells sunglasses specially designed
to aid people with Macular Degeneration.
At the Medical College of Georgia and UMDNJ
- University Hospital, the same types of x-rays used to destroy tumors
in the eye are now being aimed at the back of the eye to halt the abnormal
proliferation of blood vessels behind the retina. Recent pilot studies
reported at a Radiological Society of North America meeting indicated that
radiation treatments may play a vital role in treating sub-retinal neovascularization
(SRNV). At the Cedars-Sinai
Comprehensive Cancer Center in Los Angeles, California a pilot study
is underway using low dose radiation. There is also a new technique called
stereotactic radiotherapy that uses 3D images to direct radiation to specific
blood vessels to stop bleeding.
Dr. Luther W. Brady at the Allegheny
University of Health Sciences, Philadelphia, PA has demonstrated the successful use of an applicator tipped with strontium 90. The emitted beta radiation penetrates only about 1mm of tissue, so the applicator is inserted directly (under anesthesia) into the effected eye through a small lateral incision. Further results are to be presented later this year at a meeting of the American Radium Society in New York.
In a protocol similar to X-ray radiation, Dr. Leslie T. Yonemoto and colleagues
at Loma Linda University Medical Center, Loma Linda,
CA. are using a proton beam as the radiation source. With a mean follow-up
of 11.6 months, 58% of the test subjects demonstrated improved or stable
visual acuity.
A very high risk and still controversial
procedure which involves implanting a quantity of retinal tissue from a
second trimester aborted foetus into a degenerated retina. If the cells
are not rejected by the host patient and begin to differentiate into the
correct retinal cells types, it is hoped that vision improvement will result
in a matter of months. In January 1997 the first publicized operation in
the United States was performed at the University of Chicago Medical Center
on an 80 year old patient with macular degeneration. Read the whole article
entitled Heroes
of Medicine. Previous operations in Sweden in 1994 met with very limited
success.
Doctors at the American
Academy of Ophthalmology (AAO) have warned users
of the newly-approved anti-impotence drug, Viagra and its potential side
effects on vision. There are no long-term studies available yet concerning
the use of viagra for persons with retinal eye conditions such as AMD and
retinitis pigmentosa, so they advise staying within the recommended FDA
dose level of 50 mg.
At Boston's
Massachusetts Eye & Ear Infirmary and at the Duke University Medical
Center in Durham, NC, researchers are trying to isolate the gene that triggers
macular degeneration. They hope to discover how to identify people at risk
of developing AMD. Volunteers for gene research should visit MEEI for more
information. Early detection means better treatment because once the damage
occurs, central vision usually cannot be restored.
Stargardt disease, clinically known as fundus flavimaculatus is the most common inherited form of macular degeneration and accounts for 7 percent of all inherited retinal diseases. It shows up in juveniles between 6 and 12 years of age and causes the same rapid and severe central vision loss as in the elderly. Researchers have now discovered mutations in the ABCR gene, which cause Stargardt disease, and may be close to mapping other genes responsible for retinal degeneration. Other rare forms of AMD also caused by mutation in a gene are Best's disease, Sorsby's disease, and the cblC type of cobalamin deficiency.
These are a manmade devices that are designed to replace the function of the retina. Light sensing diode arrays, miniature electronic cameras, and micro electronic circuitry are being designed now and show some promise as a means of restoring some rudimentary sight function.
Shark Cartilage and Angiogenesis*
Laser Treatments
Phi-motion Angiography*
Dye Assisted Photocoagulation
Intraocular Telescopic Lens*
Submacular Surgery
Photodynamic Therapy (PDT)*
Matrix Metalloprotease Inhibitor Designer Drug*
Retinal Pigment Removal
Microcurrent Stimulation Therapy*
Argon Laser Heat Treatment
RheoTherapy Blood Filtration*
Nutrient Studies
Confocal Laser Ophthalmoscope*
Vitamins, Minerals and Anti-Oxidants
Zinc Supplement
Eye Disease linked to Atherosclerosis?*
Sunglasses and Ultraviolet Filters
X-Ray Treatments
Strontium 90 Radiation*
Proton Beam Radiation*
Foetal Tissue Implant
Viagra (Sildenafil) Warning*
The Genetic Link
Stargardt Disease
Electronic Retinal Implant