MD, PhD, FMedSci, FSB, FRCP, FRCPEd

iridology

Non-validated diagnostic methods, like those in abundant use in alternative medicine, run an unacceptably high risk of producing false positive or false negative diagnoses. The former would be a diagnosis that the patient is, in fact, not suffering from; this enables the charlatan to get rich on treating something that is not even there. The latter would be missing an illness that might even kill the patient. Thus both scenarios are unquestionably harmful.

It is now 21 years ago that I published a review of alternative diagnostic techniques entitled ‘WHICH CRAFT IS WITCHCRAFT?’. Here is the abstract:

The prevalence of complementary medicine in most industrialised countries is impressive and increasing. Discussions of the topic often focus on therapeutic approaches and neglect diagnostic methods specific for complementary medicine. The paper summarises the data available on such “alternative” diagnostics. Scientific evaluations of these are scant, and most techniques have never been properly validated. The ones that have can be demonstrated to be not reproducible, sensitive, or specific. The ones that have not should be regarded as such until shown otherwise by rigorous testing. Therefore it seems that “alternative” diagnostic methods may seriously threaten the safety and health of patients submitted to them. Orthodox doctors should be aware of the problem and inform their patients accordingly.

Exactly 15 years after the publication of this paper, PRINCE CHARLES published his book ‘HARMONY‘ where is covers amongst many other topic also the subject of alternative diagnostics. This is what he tells us about them:

I have also learn from leading experts how we can understand a great deal about the causes of ill health through more traditional methods of diagnosis – for example, through examination of the iris, ears, tongue, feet and pulse, very much the basis of the Indian Ayurvedic system. This is not to say that modern diagnostic techniques do not have a role, but let us not forget what we can gain by using the knowledge and wisdom accumulated over thousands of years by pioneers who did not have access to today’s technology. In fact, an over-reliance can often mean that the subtle signs of imbalance revealed by the examination of the eyes, pulse and tongue are totally missed. Including the fruits of such knowledge, gleaned over 8 000 years of studying the relationship of the human body to the rest of Nature and to the Universe, can but only provide an extra, valuable resource to doctors as they seek to make a full diagnosis. Why persist in denying the immense value of such accumulated wisdom when it can tell us so much about the whole person – mind, body and spirit? Employing the best of the ancient and modern in a truly integrated way is another example of harmony and balance at work.

Charles is talking here about iridology, amongst other methods. Iridologists try to diagnose disease or susceptibility to disease by analysing the colour pattern of a patient’s iris. It happens to be a technique that has repeatedly been put to the test. In 1999, I published a systematic review of the evidence and concluded that the validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.

Given that the evidence for alternative diagnostic techniques is either negative or absent, why does the heir to the throne advocate using them? Does he not know that he has considerable influence and endangers the health of those who believe him? Why does he call this nonsense valuable? The answer probably is that he does not know better.

There is nothing wrong with Charles’ ignorance, of course. He is not a medic (if he were, his quackery might get him struck off the register!) and does not need to know such things! But, if he is ignorant about certain technicalities, should he write about them? At the very least, when giving such concrete medical advice about diagnostic methods, should he not recruit the expertise of people who do know about such matters?

In Charles’ defence, I should mention that apparently he did ask several physicians for help with his book. Two of those who he acknowledged in HARMONY have been mentioned on this blog before: Mosaraf Ali and Michael Dixon.

I MIGHT BE MISTAKEN, BUT IT SEEMS TO ME THAT CHARLES IS NOT JUST IGNORANT ABOUT MEDICINE BUT ALSO ABOUT THE ART OF CHOOSING EXPERTS.

We used to call it ‘alternative medicine’ (on this blog, I still do so, because I believe it is a term as good or bad as any other and it is the one that is easily recognised); later some opted for ‘complementary medicine’; since about 15 years a new term is en vogue: INTEGRATED MEDICINE (IM).

Supporters of IM are adamant that IM is not synonymous with the other terms. But how is IM actually defined?

One of IM’s most prominent defenders is, of course Prince Charles. In his 2006 address to the WHO, he explained: “We need to harness the best of modern science and technology, but not at the expense of losing the best of what complementary approaches have to offer. That is integrated health – it really is that simple.”

Perhaps a bit too simple?

There are several more academic definitions, and it seems that, over the years, IM-fans have been busy moving the goal post quite a bit. The original principle of ‘THE BEST OF BOTH WORLDS’ has been modified considerably.

  • IM is a “comprehensive, primary care system that emphasizes wellness and healing of the whole person…” [Arch Intern Med. 2002;162:133-140]
  • IM “views patients as whole people with minds and spirits as well as bodies and includes these dimensions into diagnosis and treatment.” [BMJ. 2001; 322:119-120]

During my preparations for my lecture at the 16th European Sceptics Congress in London last week (which was on the subject of IM), I came across a brand-new (September 2015) definition. It can be found on the website of the COLLEGE OF MEDICINE  This Michael Dixon-led organisation can be seen as the successor of Charles’ ill-fated FOUNDATION FOR INTEGRATED HEALTH; it was originally to be called COLLEGE FOR INTEGRATED MEDICINE. We can therefore assume that they know best what IM truly is or aspires to be. The definition goes as follows:

IM is a holistic, evidence-based approach which makes intelligent use of all available therapeutic choices to achieve optimal health and resilience for our patients.

This may sound good to many who are not bothered or unable to think critically. It oozes political correctness and might therefore even impress some politicians. But, on closer scrutiny, it turns out to be little more than offensive nonsense. I feel compelled to publish a short analysis of it. I will do this by highlighting and criticising the important implications of this definition one by one.

1) IM is holistic

Holism has always been at the core of any type of good health care. To state that IM is holistic misleads people into believing that conventional medicine is not holistic. It also pretends that medicine might become more holistic through the addition of some alternative modalities. Yet I cannot imagine anything less holistic than diagnosing patients by merely looking at their iris (iridology) or assuming all disease stems from subluxations of the spine (chiropractic), for example. This argument is a straw-man, if there ever was one.

2) IM is evidence-based

This assumption is simply not true. If we look what is being used under the banner of IM, we find no end of treatments that are not supported by good evidence, as well as several for which the evidence is squarely negative.

3) IM is intelligent

If it were not such a serious matter, one could laugh out loud about this claim. Is the implication here that conventional medicine is not intelligent?

4) IM uses all available therapeutic choices

This is the crucial element of this definition which allows IM-proponents to employ anything they like. Do they seriously believe that patients should have ALL AVAILABLE treatments? I had thought that responsible health care is about applying the most effective therapies for the condition at hand.

5) IM aims at achieving optimal health

Another straw-man; it implies that conventional health care professionals do not want to restore their patients to optimal health.

In my lecture, which was not about this definition but about IM in general, I drew the following six conclusions:

  1. Proponents of IM mislead us with their very own, nonsensical terminology and definitions.
  2. They promote two main principles: use of quackery + holism.
  3. Holism is at the heart of all good medicine; IM is at best an unnecessary distraction.
  4. Using holism to promote quackery is dishonest and counter-productive.
  5. The integration of quackery will render healthcare not better but worse.
  6. IM flies in the face of common sense and medical ethics; it is a disservice to patients.

Ignaz von Peczely (1826-1911), a Hungarian physician, got the idea for iridology (or iris-diagnosis) more than a century ago, after seeing streaks in the iris of a man he was treating for a broken leg, and similar phenomena the iris of an owl whose leg von Peczely had broken many years before. He subsequently became convinced that his method was able to distinguish between healthy organs and those that are overactive, inflamed, or distressed. Iridology became internationally known when US chiropractors began adopting this method in their clinical practice. In the United States, most insurance programs do not cover iridology but, in some European countries, they often do. In Germany, for instance, 80% of the Heilpraktiker (non-medically qualified health practitioners) practice iridology.

Iridologists claim to be able to diagnose the health status of an individual, medical conditions or predispositions to disease through abnormalities of pigmentation in the iris. The popularity of iridology renders it necessary to ask whether this method is valid.

The aim of my systematically review from 1999 was to critically evaluate all available, reliable tests of iridology as a diagnostic tool. Four case control studies were included; these are investigations where iridologists are asked to tell by looking at the iris of individuals whether that person does or does not have a certain condition. The majority of these studies suggested that iridology is not a valid diagnostic method. Back then, I concluded that “the validity of iridology as a diagnostic tool is not supported by scientific evaluations. Patients and therapists should be discouraged from using this method.”

Since the publication of my article, several further studies have emerged:

One German team conducted a study investigating the applicability of iridology as a screening method for colorectal cancer. Digital color slides were obtained from both eyes of 29 patients with histologically diagnosed colorectal cancer and from 29 age- and gender-matched healthy control subjects. The slides were presented in random order to acknowledged iridologists without knowledge of the number of patients in the two categories. The iridologists correctly detected 51.7% and 53.4%, respectively, of the patients’ slides; therefore, the likelihood was statistically no better than chance. Sensitivity was, respectively, 58.6% and 55.2%, and specificity was 44.8% and 51.7%. The authors’ conclusion was blunt: “Iridology had no validity as a diagnostic tool for detecting colorectal cancer in this study.”

A study from South Africa aimed to determine the efficacy of iridology in the identification of moderate to profound sensorineural hearing loss in adolescents. A controlled trial was conducted with an iridologist, blind to the actual hearing status of participants, analysing the irises of participants with and without hearing loss. Fifty hearing impaired and fifty normal hearing subjects, between the ages of 15 and 19 years, controlled for gender, participated in the study. An experienced iridologist analysed the randomised set of participants’ irises. A 70% correct identification of hearing status was obtained with a false negative rate of 41% compared to a 19% false positive rate. The respective sensitivity and specificity rates therefore were 59% and 81%. The authors of this investigation concluded that “iridological analysis of hearing status indicated a statistically significant relationship to actual hearing status (P < 0.05). Although statistically significant sensitivity and specificity rates for identifying hearing loss by iridology were not comparable to those of traditional audiological screening procedures.”

A further German study investigated the value of iridology as a diagnostic tool in detecting some common cancers. One hundred ten subjects were enrolled; 68 subjects had histologically proven cancers of the breast, ovary, uterus, prostate, or colorectum, and 42 were cancer-free controls. All subjects were examined by an experienced practitioner of iridology, who was unaware of their medical details. He was allowed to suggest up to five diagnoses for each subject and his results were then compared with each subject’s medical diagnosis to determine the accuracy of iridology in detecting malignancy. Iridology identified the correct diagnosis in only 3 cases (sensitivity, 0.04). The authors concluded that “iridology was of no value in diagnosing the cancers investigated in this study.”

Based on these results it is impossible, I think, to claim that iridology is a valid or useful diagnostic tool. As there is no anatomical or physiological basis for its assumptions, iridology is not biologically plausible. Furthermore, the available clinical evidence does not support its validity as a diagnostic tool. In other words, iridology is bogus. This statement is in sharp contract to the information consumers receive about the method on uncounted websites, books, articles, etc. One website picked at random provides the following information:

The iris reveals changing conditions of every part and organ of the body. Every organ and part of the body is represented in the iris in a well defined area. In addition, through various marks, signs, and discoloration in the iris, nature reveals inherited weaknesses and strengths.

By means of this art / science, an iridologist (one who studies the coloration and fiber structure of the eye) can tell an individual his/her inherited and acquired tendencies towards health and disease, his current condition in general, and the state of every organ in particular.

Iridology cannot detect a specific disease, but, can tell an individual if they have over or under activity in specific areas of the body. For example, an under-active pancreas might indicate a diabetic condition.

Another source claims:

The underlying platform of iridology is that that eyes act as a ‘window’ to a person’s health & well being. This ‘window’ enables the practitioner to see whether areas or organs within the body are healthy, inflamed or ‘over active’. It also enables them to assess a person’s past/ possible future health problems & consider if the patient has a susceptibility to certain diseases. It is important to understand that iridology is simply a method of diagnosis & analysis.

You may well think that none of this really matters. Who cares whether iridology is bogus or not! I would argue that it does matter. Bogus methods cost money that could be better spent elsewhere. More importantly, false positive and false negative diagnoses generated by bogus diagnostic methods can put lives at risk.

But there is a more general and perhaps more crucial point here: alternative medicine is an area where people far too easily get away with ignoring the published evidence and scientific consensus. In the last two decades, I have seen many alternative modalities getting scientifically dis-proven; not in a single such instance can I remember that the corresponding alternative practitioners and their professional organisations took any notice of this fact, and not once did I notice that their practice had changed.

If research is  systematically ignored, it becomes a useless appendix. More importantly, progress is then stifled to the detriment of all our best interests.

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