Cold Laser, Low Level Laser, Anodyne… Bogus for Neuropathy

Does anodyne light therapy improve peripheral neuropathy in diabetes? A double-blind, sham-controlled, randomized trial to evaluate monochromatic infrared photoenergy. Lavery LA, Murdoch DP, Williams J, Lavery DC. Diabetes Care. 2008 Feb;31(2):316-21.

Abstract
OBJECTIVE:
The purpose of this study was to determine the efficacy of anodyne monochromatic infrared photo energy (MIRE) in-home treatments over a 90-day period to improve peripheral sensation and self-reported quality of life in individuals with diabetes.

RESEARCH DESIGN AND METHODS:
This was a double-blind, randomized, sham-controlled clinical trial. We randomly assigned 69 individuals with diabetes and a vibration perception threshold (VPT) between 20 and 45 V to two treatment groups: active or sham treatment. Sixty patients (120 limbs) completed the study. Anodyne units were used at home every day for 40 min for 90 days. We evaluated nerve conduction velocities, VPT, Semmes-Weinstein monofilaments (SWM) (4-, 10-, 26-, and 60-g monofilaments), the Michigan Neuropathy Screening Instrument (MNSI), a 10-cm visual analog pain scale, and a neuropathy-specific quality of life instrument. We used a nested repeated-measures multiple ANOVA design. Two sites (great toe and fifth metatarsal) were tested on both the left and right feet of each patient, so two feet were nested within each patient and two sites were nested within each foot. To analyze the ordinal SWM scores, we used a nonparametric factorial analysis for longitudinal data.

RESULTS:
There were no significant differences in measures for quality of life, MNSI, VPT, SWM, or nerve conduction velocities in active or sham treatment groups (P > 0.05).

CONCLUSIONS:
Anodyne MIRE therapy was no more effective than sham therapy in the treatment of sensory neuropathy in individuals with diabetes.

My comments:
 
Anodyne is a brand name for cold laser, low level laser, monochromatic infrared photo energy (MIRE, I would have called it MIPE), red beam, near infrared, far infrared, and probably a lot of new names to come out in the future to refresh an old idea.

What I thought was particularly interesting about this study, was that the manufacturers came up with a sham/placebo device that was so convincing, that neither the patients, nor the investigators could tell which device was which. At the end of the study, it  turned out that unlike in prior poorly controlled, or even fully uncontrolled studies, they found no treatment effect whatsoever that was greater than the sham treatment. In fact, the authors commented:

“If these studies had failed to include a sham therapy arm, MIRE would appear to provide significant improvement in peripheral sensation because of the placebo effect. This effect may help explain the observations in uncontrolled studies showing that MIRE was effective.”

“Not only was there no clear benefit from the treatment, but there was also a large placebo effect in which the sham therapy showed double the number of improvements in the effect size compared with the anodyne treatment.

These results make me feel bad for Anodyne, in that they went out of their way to construct a bomber sham device, and in doing so they scientifically sawed off the branch which they were sitting. Doing so makes me think they honestly thought they were on to something. Stephen Barrett of quackwatch.com did write up on low level laser therapy, which is really bad news for your treatment.

Interestingly enough, I decided to give the infrared photoenergy treatment a try. This all came about because I was at a gym talking about something exercise and EMS related in front of a durable medical goods provider, who suggested I try a low level laser treatment, and really thought he would convince me of its effectiveness. I didn’t have much in the way of placebo effect because I had already read Dr. Barrett’s critique. Even so, I was still curious as to what low level laser felt like, especially since it was supposed to have a good placebo effect, it should feel like something. However, I was fully underwhelmed with the process. Honestly, it felt like nothing; no warmth, no tingling. In fact, if I didn’t see the purple lights, I wouldn’t have been able to tell that it was on. You know how it feels when you shine an old D-cell flashlight against your hand when you are a kid and your fingers glow red from the other side? I suspect that’s the source of the placebo effect. It looks kind of cool, but you can’t feel anything? Well, turns out it was exactly like that. This study would tend to suggest that low level laser therapy works about as well as shining a flashlight against you, which is no real effect at all, unless of course you are really open to the power of suggestion. How much was the DME asking for his fancy flashlight with the purple color filter you ask? Only $4700. Sorry, no sale, but I felt all good about myself for being open minded enough to try it and the salesman sincerely thought I was going to like it.

It would be really neat if ineffective treatment modalities were discontinued, but I guess if you are a chiropractor or physical therapist who paid several thousand dollars for a device only to find it didn’t work, you still want to use it. On top of that, it sucks to admit you made a mistake and just toss it in your backroom. I say this because this situation actually happened to me with my ultrasound machine that I haven’t used in 10 years. From experience, I say suck it up, be a professional, and stop fooling your patients. Practicing science or evidence based medicine means that you may have to stop doing things you used to do when you find out, in fact, that they don’t really work. If you continue with the same practices because “it seems like it’s working,” well, you got placeboed too right along with your patient, and having that graduate degree means you should be beyond all that. If you do it just because it pays the bills, well, you’re selfish. In either case, STOP.

As always, if you have any further questions or need for clarifications, please don’t hesitate to ask. Being aware that some of my blog ideas are contentious and occasionally a bit out of the field of my expertise, I encourage my readers to come forth with any questions/comments that are of interest or concern. Your comments are valued and welcomed.

Chad Reilly is a licensed physical therapist, located in North Phoenix, practicing science based medicine with treatment protocols unique and effective enough to proudly serve patients from Phoenix, Scottsdale, Mesa, Chandler, Tempe, Peoria, and Glendale.

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