What AMD does to vision
This post is dedicated to two people who are frequent commenters on SBM, Stephen S. Rodrigues and Peter Moran. Rodrigues is an MD/acupuncturist who tries to persuade us that acupuncture is effective. Moran is a retired surgeon who objects to insulting language and thinks more can be accomplished by trying to better understand why people turn to CAM and by explaining the facts and reasons politely and dispassionately. He has claimed that he “could probably help [Rodrigues] understand better why his views are not having much impact.”
I recently wrote about supplements for age-related macular degeneration (AMD). There is evidence that the supplement mixture tested in the AREDS trial slows the progression of moderate to advanced disease. That is based on a good scientific study, although the study has not been replicated and there is reason to interpret its results with caution. Dr. Rodrigues commented with a link to a website advertising the Santa Fe acupuncture protocol, saying that he uses the method in his office and it helps some of his patients with AMD. The website claims that the Santa Fe acupuncture protocol will reverse vision loss from macular degeneration in 4 days or your money back. That is a bold claim. I will try to explain, as politely as possible, why I reject the claim, and why the evidence for it is unacceptable. (more…)
Picture of the human retina; the bright spot on the right is the blind spot where the optic nerve leaves the eye.
Steven Novella recently wrote about so-called “chiropractic neurology” and its most outspoken proponent, Ted Carrick. In 2005 I published an article in The Scientific Review of Alternative Medicine (Vol 9, No 1, p. 11-15) entitled “Blind-Spot Mapping, Cortical Function, and Chiropractic Manipulation.” It was an analysis of a study Carrick had published.
Carrick read a shorter, popularized version of my critique in Skeptical Inquirer and responded with a diatribe that was inaccurate, distorted what I had said, and accused me of fraud, deception, and mis-representation. He failed to offer a credible rebuttal of my specific criticisms; and, in my opinion, showed that he failed to understand some of my points. He referred to me as “Ms. Hall” and suggested that I was psychotic. He characterized my e-mail correspondence with him as “bizarre, rude, and offensive.” It was none of those, and I have copies of the e-mails to prove it. Carrick says he “forwarded it to the legal council for the American Chiropractic Association for review.” Now that strikes me as bizarre.
I am re-publishing the entire text of my article here as an instructive example of what passes for science in the chiropractic neurology community. Readers can judge for themselves whether my critique amounts to fraud and whether I am showing signs of psychosis, whether Carrick is a good scientist and whether his reply to my critique was appropriate. (more…)
An recent article in the journal Ophthalmology reported the results of a clinical trial that evaluated acupuncture as an adjunctive treatment for anisometropic amblyopia. In the abstract, the authors conclude:
Acupuncture is a potentially useful complementary treatment modality that may provide sustainable adjunctive effect to refractive correction for anisometropic amblyopia in young children. Further large-scale studies seem warranted.
A little background information is in order.
In a healthy visual system the various structures in the eye focus light ambient light to form a sharp image on the retina. The retina functions like the CCD in a digital camera. Light energy is transduced to electrical signals, which are transmitted through the optic nerve. The signals from the optic nerve are relayed to the occipital cortex (at the very back of the brain) where they are interpreted into the experience of vision.
Amblyopia is often called “lazy eye”. If during childhood the brain is deprived of quality visual information it does not mature properly and loses the potential for good vision. Any opacity within the eye which significantly degrades the quality of the image forming on the retina (such as congenital cataract) can cause amblyopia. Strabismus (misalignment of the 2 eyes) can also cause amblyopia. If the eyes are not aligned, the brain has difficulty reconciling the disparate images from the 2 eyes. In order to avoid double vision the brain may “ignore” the input from one eye, and corresponding part of the visual cortex will not develop properly. Extreme, uncorrected, refractive errors (nearsightedness, farsightedness or astigmatism) can cause amblyopia. Patients with different refractive errors in their 2 eyes, a condition known as anisometropia, can also develop amblyopia in one eye.
Age-related macular degeneration (AMD) is one of the major causes of visual impairment in the elderly: it affects central vision, impairing the ability to read and recognize faces while preserving some peripheral vision. It comes in two forms: wet and dry. Dry macular degeneration is by far more common, but wet macular degeneration, involving the proliferation of blood vessels, is more severe.
There is evidence that antioxidant vitamin supplementation may slow the progression of the dry type when it is already established and moderately severe, but the published evidence does not support the use of these supplements for prevention or for patients with early stages of the disease. Some people are using it for prevention, but there is concern that the risks might exceed any benefit. Of more concern, it appears that a manufacturer’s (Bausch & Lomb’s) advertising has gone way beyond the available evidence. (more…)
Charlene Werner is getting a lot of attention she probably did not anticipate or desire. She is the star of a YouTube video in which she explains the scientific basis of homeopathy. Before you watch it, make sure you are sitting down, relax, and brace yourself for an onslaught of profound scientific illiteracy combined with stunning arrogance. For those with more delicate constitutions I will give you the quick summary:
Einstein taught us that energy equals matter and light, but because matter can be condensed down to a very small space if you remove all the empty space between the elementary particles (I am paraphrasing to make her statements minimally coherent), we can mostly ignore matter. Therefore energy is light, and we are all made of energy – not matter (or at least so little matter, you can ignore it). Stephen Hawking then came up with string theory, which tells us that all matter (which we can ignore) is made of vibrating strings. Therefore we are made of vibrating energy. All diseases are therefore caused by unhealthy vibrational states, and all disease can be treated by returning the body to a previous healthy vibrational state. This can be done with homeopathy, which extracts the vibrational energy out of stuff and places it in a small pill that can be used at any time.
Got it? This is now my favorite example of meaningless pseudobabble from a CAM proponent. Also, I am not picking on some unrepresentative crank – this is as good as homeopathy gets. Werner may be more clumsy and fumbling than more eloquent homeopathy proponents, but when you strip it down, magical vibrations is what you get. But Werner does a fabulous job of exposing the gaping holes is homeopathic nonsense.