LEDs Shed New Light On Therapy Options

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If you’re like most of us, you’re interested in any ideas that will help get your horse back in the ring if he’s injured. As the use of high-tech therapies continues to grow in the veterinary community, you’ll likely to be given the option of using an LED. Our advice' Know beforehand what LEDs can and can’t do, and lease one before buying it.

Like lasers (see April 2000), light-emitting diodes (LEDs) deliver a concentrated dose of light energy to the tissues. And again like lasers, the primary wavelengths are red and infrared. The difference is that LEDs aren’t likely to penetrate tissues to the same depth as a laser.

LEDs also aren’t as focused. While lasers have a single diode (light source), a tiny aperture and a crystal that focuses the beam precisely, LEDs usually use multiple diodes and deliver the light energy in a diffuse pattern over a wider area. This again results in less tissue penetration, but the total amount of light energy (joules) delivered to the treatment area is much higher than with a laser. Confused' That’s OK.

Even the experts can’t agree on how the technical differences between lasers and LEDs translate into different biological effects. In fact, they aren’t even sure if equations used to calculate the energy being delivered to the tissues by a laser can be accurately used for LEDs.

Research
The little research available on LEDs suggests that it is the wavelength of light used, not whether it is coherent, that accounts for the effects noted on tissues.

Tissue cells in culture dishes respond similarly to LEDs and lasers. LED proponents point to these studies as proof that LEDs work the same as lasers. They then make the jump to assume that all research done on the effects of lasers can be applied to LEDs as well.

The problem is that when it comes to clinical studies on live animals and people, there are few for LEDs. In fact, the clinical studies we saw that LED manufacturers quote to support their effects were all done using true lasers, not LED devices.

We did find a handful of studies regarding LEDs in a clinical setting. Most involve their use to treat open wounds. In this setting, LEDs perform as well as lasers, if not better.

The only other study we found used Doppler ultrasound, which measures blood flow, to evaluate the response of blood vessels on the scalp to two different types of lasers and an LED device. Interestingly, one low-power density laser had no measurable effect and a more powerful infrared laser caused a significant increase (54%) in blood flow. The LED device caused a significant reduction (36%).

The researchers did not specify how long the areas were exposed or the total dose of light radiation they received, nor did they mention if the light was pulsed at different frequencies. This makes it difficult to pinpoint exactly what might have been going on. However, two conclusions can be drawn:

1) Both lasers and LEDs are capable of causing a measurable effect on blood flow in superficial blood vessels, and

2) The effect you get is not necessarily the same.

Mechanics And Applications
LEDs can be used to focus on obvious problem areas, such as a bowed tendon, or they can be used to treat the “whole horse,” using an acupuncture philosophy.

The LED devices we tested include both red and infrared diodes in their cluster (many diodes) heads. (One LED model also included green diodes for “surface treatment.”) Treatment times for localized problems are relatively short — one to three minutes per spot — and is further decreased when using cluster heads, which will cover two- to 12-inch diameter areas.

Products And Results
Our product chart on page 5 details products from the companies we evaluated, BioScan and Light Force Therapy, Inc. When using the cluster heads to treat local problems, treatment times are from one to four minutes per spot. The entire involved area is treated, as well as a short distance of normal surrounding tissue.

The Super Nova from Light Force covers an area 18 times greater than using the two cluster heads that come with the BioScan BioPack. However, BioPack’s dosage of light delivered per unit of tissue under the light is estimated to be over 18 times greater than the Super Nova. This really results in little difference in the time it takes to treat an area.

Both units were extremely effective in promoting the healing of wounds, as was the optional red light LED cluster head in the Thor laser we discussed in April. Both also worked well to relieve muscular pain and spasm without creating any obvious painful/avoidance reaction from the horse. However, many horses did appear to “feel” the treatments, as evidenced by looking around, ear pinning, tail swishing, etc.

Pain relief resulting from local treatment of problem joints, tendons or ligaments was not impressive but improved when the whole horse was treated. An exception to this was the response seen in both acute and chronic joint problems when using the BioScan leg savers (see sidebar).

One of the most interesting responses was observed when treating inflammation. The BioScan treatment guides suggest a low frequency (146 hertz) and short exposure times/low doses (one joule or less) when treating inflammation, while the Light Force Therapy unit uses high frequencies and six- to eight-joule doses. However, when you consider that the high dose is spread out over a much greater surface area, the dosage per unit of tissue is the same to even lower when using Light Force.

Despite the different frequencies chosen, both units effectively reduced heat and swelling. Whether this is an effect on inflammatory cells or as a result of reducing blood flow as a direct effect (or both) is unclear.

Although the LEDs helped reduce heat and swelling in injured tendons and ligaments, and therefore provided a little pain relief, we were unable to find evidence of more rapid healing. We followed the course of curbs, a flexor tendon injury and a suspensory injury — the last two studied at regular intervals by ultrasound exams. While they all looked better externally with LED treatments, there was no clinical or ultrasound evidence of improved healing.

The curbs did respond to treatment with a true laser, while the tendon and suspensory injuries showed markedly improved healing with PEMF (pulsed electromagnetic field, Respond system) treatments.

We received details from a veterinarian concerning a tendon injury that was treated with the BioScan equipment. Healing had been slow prior to starting the treatment and progressed rapidly afterward. However, it was not clear if the horse had been properly rested before starting the BioScan treatments. We also don’t know if it was the tendon/shin saver that was used or the Biopack heads.

By far the most dramatic effects in terms of both systemic reactions and enhanced pain relief were seen when whole-body treatments were performed. The BioScan system includes the BioFind, a device for detecting areas of abnormal electrical resistance on the surface of the skin. These points correspond to either areas of injury or reactive acupuncture points.

The system comes with a green marking crayon that is used to mark these spots on the horse’s body. We performed over 200 BioFind scans in the course of our evaluation and found anything from no reactive spots to as many as 85 points on a single animal. Some obviously overlie areas of injury/soreness, others are located along acupuncture meridians, while some defy explanation.

The idea is that injuries, particularly chronic injuries, lead to compensations elsewhere in the body and new areas of soreness/injury. Also at work are energy (“Chi” in acupuncture terms) blockages and imbalances. The points are all treated for 30 seconds with the BioPack clusters (or single diodes in other BioScan equipment), and the animal is rescanned in 24 to 48 hours.

The reaction to this whole-body treatmen t is often dramatic relaxation if a large number of points are treated. Some horses actually appeared sedated/tranquilized, an effect that often lasted several hours.

Gait is also more fluid and relaxed, adding to any benefit obtained from local treatment of problem areas. Maximal benefit in terms of gait and pain relief are apparent after 24 to 48 hours.

Repeat scanning usually reveals fewer points, but new ones also commonly appear as a result of what the company calls “unlayering,” which involves relieving secondary problems so you can see the underlying root cause more clearly. The process continues until all abnormal points disappear or you are left with a core of recurrent points that will require long-term maintenance therapy one to three times per week.

The Light Force system doesn’t use any sensing devices but recommends a system of whole-body treatments that follow the lines of acupuncture meridians, the paths taken in the flow of Chi through the horse’s body (you’ll need an acupuncture map/chart).

An alternative to an acupuncture map is to systematically cover every inch of the horse’s body, beginning at the muzzle, going to ears, then to the poll, following the spine to the tail tip. You then treat the large anatomical areas (chest, shoulders, rump, each leg inside and out), going from front to back and from top to bottom. The unique low-frequency setting (eight hertz) on this equipment corresponds to the frequency of the brain’s theta waves and is designed to relax the animal.

As with the BioScan whole-horse treatments, there is a noticeable relaxing and analgesic response although it is not as profound as that seen with the BioScan when treating a large number of points.

Bottom Line
LED therapy is most indicated for:

?'?Wounds: If you have an open and/or problem wound, consider leasing a unit. Wounds respond well.

?'?Inflammatory Reactions: Heat and swelling responded extremely well to LED therapy.

?'?Arthritis: The BioScan Leg Saver joint boots/wraps were effective in alleviating mild-to-moderate stiffness, swelling and pain in arthritic joints. Otherwise, we prefer the arthritis therapies discussed in our May 2000 issue.

?'?Problem Backs: Vertebral and/or muscular problems in the back responded well.

?'?Performance-Related Muscular Pain: Good response.

?'?Chronic/Complicated Lameness Or Stiffness: Whole-body LED treatments are ideal for these horses.

The BioFind is pricey, but it does offer some unique advantages. In most cases, we would recommend the more economical combo of the BioFind and BioPack in the BioBelt rather than single purchases. However, we like the BioScan Leg Saver Boots for the symptomatic treatment of stiff, sore joints.

With a small difference in price and comparable clinical results, it’s a toss-up between the BioPack cluster system and the Super Nova. However, if you’re going to pass on the point finder, the Super Nova’s greater treatment area will allow you to cover the meridians in much less time. For even greater savings, the smaller diameter cousin of the Super Nova, the Acubeam, gives you the same frequency options at an $800 saving.

As always with expensive therapies, we suggest leasing first. Check with the manufacturers regarding current availability and price.

Also With This Article
Click here to view "The BioScan Light Cap."
Click here to view "LED-Use Chart: Local Problems."
Click here to view "Safety."
Click here to view "Thor LED Option."
Click here to view "LED Products."
Click here to view "BioScan Leg Savers."
Click here to view "Systemic Effects."
Click here to view "BioFind Pros And Cons."