By Cari Cannon, O.D.
Editor's Note: This informative article on two contrasting subjects, herbal medicine and the latest technologies in eye care comes from our good friend, Cari Cannon, O.D. in West Roxbury, MA (U.S.) - LMB
April 6, 2009
Herbal Medicine is the oldest form of medicine known to mankind and herbs have played an important part in our development. More than 2,000 years ago, Hippocrates wrote extensively about herbal medicine and healing. Dioscordies, a Greek
surgeon in Nero’s army (54 - 68 AD), described more than 600 plants in his extensive De Materia Medica. It was the mainstay of many early civilizations and still the most widely practiced form of medicine in the world today.
Currently, approximately 25% of all prescription drugs are derived from trees, shrubs or herbs. The World Health Organization estimates that 4 billion people, 80% of the world’s population, presently use herbal medicines for some aspect of their primary health care.
The essential difference between herbalism and conventional medicine is that in herbal medicine extracts from the whole plant are used; while in conventional medicine, the most active constituent is extracted from the plant and then synthesized in the laboratory to make a "drug."
Digitalis is a powerful drug extracted from the leaves of foxglove herb - The discovery of the cardioactive properties of foxglove (Digitalis purpurea Linnaeus) was perhaps one
of the most important steps toward modern medicine. In the 1780s, William Withering came to understand the correlation between heart function and health. Withering didn't know why foxglove worked but he knew when the heart beat stronger, fluid retention (edema) decreased and his patients got better.
Unfortunately, the cardioactive properties of foxglove varied from plant to plant; even the stage of the plant's life made a difference in the quantity of the drug present. Dosages were an educated guess. Withering almost killed a patient with Digitalis leaf and his reputation often suffered, due to the unpredictability of side-effects. Not until the mid-1800s would chemists begin extracting and separating the cardioactive glycosides. Almost another hundred years would pass before all the compounds were elucidated, dosages computed and pure, standardized digitalis-extract began saving more lives than it ended.
Morphine and Codeine are derived from the opium poppy. Scholars believe that man first discovered the opium poppy growing wild in mountains bordering the eastern Mediterranean sometime in the Neolithic Age. It was known to Hippocrates in Greece and in Roman times to the great physician Galen. Although physicians had used various forms of opium for three or four thousand years, it was not until 1805 that medical science finally extracted pure morphine from raw opium. Orally taken, morphine soon became an important medical anesthetic. It was not until 1858 that two American doctors first experimented with the use of the hypodermic needle to inject morphine directly into the bloodstream. These discoveries were important medical breakthroughs, and they greatly improved the quality of medical treatment in the nineteenth century.
Cancer Prevention and Herbs– The use of an ancient herbal remedy for lung cancer prevention is now being studied at the BC Cancer Agency in Vancouver. Lung cancer is the most common cause of cancer death in men and women in Canada and the U.S. More people die each year from lung cancer than from breast, colon, and prostate cancers combined.
The Lung Health Study at BCCA, headed by Dr. Stephen Lam, is testing the most recent in a series of chemopreventive agents aimed at reducing the amount of pre-cancerous cells in the lungs of smokers and ex-smokers. The agent being studied, ACAPHA, is a combination of six herbs and has been used for disease prevention in China for centuries. In earlier studies in China, ACAPHA has been shown to reduce the risk of esophageal cancer by 40 to 50 percent. A preliminary open study at BCCA also showed promising results in preventing the development and progression of pre-cancerous lesions in the lung.
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Devil's claw root |
Osteoarthritis - Several studies have found that taking devil's claw (an herb used forthousands of years by the Khoisan peoples of the Kalahari Desert) can substantially reduce pain and improves physical functioning in people with osteoarthritis. In a large, well-designed 4-month study including 122 people with knee and hip osteoarthritis, devil's claw root powder reduced pain and improved functional ability as effectively as standard doses of a leading medication for osteoarthritis. Additionally, those who received devil's claw experienced fewer side effects and required fewer pain-reducing medications throughout the study.
Inflammation- Goldenseal is an herb that was introduced to the early American settlers by the Cherokee Indians for its antiseptic wound-healing properties. Goldenseal Root is extracted from the dried roots (rhizome) of the small forest plant Hydrastis canadensis. It can also be used for its soothing action on inflamed mucous membranes. Goldenseal's major healing compounds are thought to be alkaloid compounds called hydrastine and berberine. The latter has been more widely researched; studies have shown that it can kill microbes, reduce inflammation and possibly stimulate immunity.
Herbal Side Effects - Herbal remedies are generally less likely to cause unpleasant side effects than orthodox drugs. Medicinal plants can contain a variety of phytochemicals as well as minerals, vitamins and trace elements. Some of these are pharmacologically active and can exert a therapeutic action on the body. However, it should be borne in mind that plant remedies are very powerful and can be dangerous, if prescribed dosage is exceeded. Herbal remedies should not be taken alongside conventional drugs or in pregnancy without consulting your doctor. If you are scheduled for surgery, stopping herbal supplements for a time prior to surgery is recommended.
Potency and purity - The efficacy of botanical extracts in Western medicine is gaining increasing recognition. However, how an herb or botanical is harvested, how it is processed and when and if it is tested for purity can make a major difference in the quality and effectiveness of a product. Unlike manufacturers of pharmaceuticals, U.S. supplement producers have no set national guidelines to follow. Supplement quality is the responsibility of manufacturers and comes down to purity of ingredients. The recent growth of herbal and botanical products contributes to this problem, as manufacturers' level of experience may vary greatly.
Have a Vision Question? If one picture is worth a thousand words, then one video should be worth at least a thousand pictures! If you have ever had a question about either your eyes or your vision, you might find the answer to your question if you: Browse Our Video LibraryWhat Causes Presbyopia?
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Cari Cannon, O.D. |
Presbyopia, also known as the “short-arm syndrome" is a normal part of the eye's aging process that causes near vision to become difficult. Onset is usually between the ages of 40 and 50 and it affects the majority of people. The name presbyopia comes from the Greek word presbus, meaning old man. In young people, the lens of the eye is soft and flexible. The most commonly accepted explanation for presbyopia is that a gradual hardening of the lens takes place over time. Hardening of the lens is thought to reduce its ability to change shape and bring near objects into focus. Presbyopia is often confused with "farsightedness" (hyperopia), which is a term used to describe how the eye focuses distant objects, when the eye's focusing system is in a relaxed state.
Presbyopia is often confused with "farsightedness" (hyperopia), which is a term used to describe how the eye focuses objects, when the eye's focusing system is in a relaxed state.
- Presbyopia Symptoms and Signs
- Difficulty seeing clearly for close work
- Print seems to have less contrast
- Brighter, more direct light required for reading
- Fatigue and eyestrain when reading
- Presbyopia Treatment - Eyewear
Traditionally, bi-focal glasses were prescribed to compensate for presbyopia with the bottom section of the lenses used for close work. Benjamin Franklin invented bifocals to avoid having to carry a pair of glasses for distance and a second pair for reading. Today, many patients choose "Progressive Addition Lenses" (PALs), which provide vision correction for all distances. Progressive lenses do not have the "dividing line" visible in traditional bifocals.
Reading glasses are another choice. Unlike bifocals and PALs, which
are usually worn all day, reading glasses are typically worn just during reading and close work. If you wear contact lenses, your eye doctor can prescribe reading glasses that you can wear over your contact lenses.
There are also contact lenses for presbyopes called "multifocal" contact lenses. They are available in both gas permeable or soft lens materials. Another type of contact lens correction for presbyopia is monovision, in which one eye wears a distance contact lens and the other wears a contact lens for near vision. While some people are delighted with this solution, others complain of dizziness, nausea or reduction in their depth perception.
Presbyopia is a normal part of the aging process. Today, there are a number of treatments available. The specific treatment chosen should take into account the individual’s age, lifestyle, occupation and hobbies. Your eye doctor is the best one to recommend which solution is appropriate for you and your particular vision needs.
Just like a fingerprint, each person's vision is unique to their eyes. Until recent advancements in technology, doctors were only able to use standard measurement techniques to correct vision. Essentially, the same prescription was used to design glasses, contact lenses or a laser vision treatment procedure.
In 2003, refractive surgery experienced an exciting development when the US Food and Drug Administration (FDA) granted approval for custom laser vision correction, also known as custom LASIK. A fundamental change in the way LASIK surgery is done, this procedure measures and corrects the focusing imperfections unique to each person's vision.
How custom LASIK works
Custom laser technology was originally developed for use in sophisticated telescopes to reduce distortions, allowing distant objects in space to be seen more clearly. In preparation for custom LASIK, a patient looks into an instrument which uses the same technology (called "wavefront") to measure light as it travels through their eyes. As the light waves travel through their eye’s optical system, any distortions are measured.
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| Light which passed through the patient's eyes is compared to light passing through an ideal eye. A three dimensional map or "optical fingerprint" of the patients eyes is created from the comparison. |
The map of the ideal or perfect eye has a flat surface. Real eyes, however, have "wavy" maps like the image at the right. Wavy maps provide information about the unique optical imperfections (aberrations) in the patient's eyes. This information is transferred to a computer that guides the laser during the custom LASIK procedure.
Benefits of Custom LASIK
How much you see depends on what lower-order aberrations you have; lower-order aberrations are also called refractive errors and include myopia, hyperopia and astigmatism. Traditional LASIK treats these lower-order aberrations. Conventional LASIK is based on a patient’s eyeglass prescription and does not include the measurements of the eye that wavefront technology provides.
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How well you see depends on what higher-order aberrations you have; higher-order aberrations are irregularities other than refractive errors, and can cause such problems as decreased contrast sensitivity or night vision, glare, shadows and halos. Higher-order aberrations do not always affect vision.
Custom LASIK treats both lower- and higher-order aberrations. 20/20 is commonly referred to as "perfect" vision. But, with custom LASIK vision correction, individuals have the potential to see even better than 20/20. In several studies, six months after receiving a custom LASIK procedure more than 70% percent of patients tested saw 20/16 or better. In a custom LASIK trial conducted by the FDA, 98% of patients achieved 20/20 vision or better, without glasses or contacts.
Are you a good candidate?
According to the FDA, you must be at least 18 years old and your glasses or contact lens prescription must be stable for at least 1 year. Stability is defined as a change of 0.5 diopter or less in your prescription over the last year. You cannot be pregnant or nursing; you cannot have collagen vascular disease and you cannot be taking certain medications. In general, over 95% of people that wear glasses or contacts are good candidates. If you've been considering laser vision correction and you meet the above criteria, check with your eye doctor for more information.
Sources:
1. American Botanical Council
2. Medline Health Information
Cari Cannon, O.D. 1819 Centre Street
West Roxbury, MA 02132
United States
617-323-0200