In this case study, Sutterfield raises several issues regarding the care of challenging ulcers. The first of which is the question of light therapy. The term light encompasses the central portion of the electromagnetic spectrum. At the longer end is infrared radiation, with wavelengths ranging from 750 nanometers (nm) to 1 millimeter (mm). These frequencies may stimulate nitric oxide production, and some studies of devices producing infrared light have shown faster wound healing, improved balance and reduced fall risk, and the improvement of diabetic peripheral neuropathy.1 Visible light ranges from red light (700 nm) to violet light (400 nm). Sunlight, of course, has been used therapeutically for centuries for its physical and psychological benefits. Ultraviolet light is made up of 3 types of radiation. Ultraviolet A (320-400 nm) and B (290-320 nm) are used to treat dermatologic conditions such as psoriasis. Ultraviolet C (200-280 nm) is antimicrobial. Each type of light has unique properties and benefits.
In this study a laser modality was used. The properties of a laser, and its subsequent use, are quite different from that of regular dispersive light. Laser light is made up of a single wavelength dispersed through a coherent beam. The wavelength selected and the power it contains varies by use, from supermarket scanners to DVD players to surgical instruments.
This case study used a device that produces several forms of light. The first is a laser beam producing 850 nm, in the infrared range. This beam is very narrow. The second light source produces light in the red and infrared range. The third form of light is visible red light. Each wavelength of light has different penetration depth into the tissue, with longer wavelengths reaching more deeply.
The efficacy of laser therapy in wound healing is not yet clear. The Cochrane Review on laser therapy for venous ulcers2 concluded that laser therapy was no more effective than sham treatment or ultraviolet treatment. However, the combination of laser and infrared light resulted in faster healing than noncohesive red light, though there were flaws in the study and baseline homogeneity was not demonstrated. Also important to note is that 2 different types of lasers were used in these studies, making comparison between studies difficult. Other reviews from the United States and the United Kingdom3,4 have reached similar conclusions, noting that the lack of effect was not likely due to a lack of significance from small sample size as there was no trending towards an effect. More recent studies are consistent with these findings.5
Animal studies have shown promise in improving acute wound healing with laser therapy, with reduced inflammation and faster progression through the phases of healing, in both diabetic and nondiabetic mice.6-9 However, acute wound healing is quite different than chronic wound healing, and findings are not always generalizable between groups. Additionally, those findings have not been replicated in humans.
Research on laser therapy has been limited by small sample sizes, inadequate control groups, inconsistent protocols, limitations in study design, and the variety of lasers available on the market. Complicating the research is the fact that chronic wounds may respond differently according to their etiology. Most of the research to date has examined venous leg ulcers. Diabetic foot ulcers and pressures may respond differently to the same treatment modalities. Yasukawa and colleagues10 demonstrated that differences in the treatment protocol, including power intensity and frequency of treatment do affect the healing outcome in rats.
The second issue addressed in this article is the value of a comprehensive plan of care. Neuropathic ulcers are multifactorial and the presence of a Charcot deformity makes treatment even more complex. Sutterfield addressed the many components of care: taking a thorough patient history including medications used, glycemic control, nutrition, patient education, offloading the foot, debridement, bioburden reduction, and moist wound healing. The author included the patient in decision-making about her care. She was able to work with the patient and her available resources, agreeing to limit expenses initially with the understanding that additional referrals and testing may be indicated if the wound failed to improve as expected. Too often the patient is kept in a passive role and told what will happen. Minimizing the dressing thickness to support the orthotic's effectiveness was an insightful consideration. A referral to physical therapy could have further assisted with reducing weight bearing on the foot.
This report demonstrates the possible benefit of laser treatment. It is impossible, however, to attribute the improvement of Ms K's wound to the use of laser, as the author notes. The previous treatment was noted as "conservative," but was not further described. Therefore it is not known whether the plan of care included all of the core components listed above. As a result, it is also unknown how many new interventions were simultaneously implemented by Sutterfield. The benefits may be attributable to any part of the plan, not necessarily laser alone. The improved overall plan of care may have been responsible for the healing. Further, the modality used included 3 types of light, each with a different mechanism of action and possible efficacy. Because the laser was implemented in conjunction with other treatments, its action cannot be isolated; it is possible that the laser may have slowed healing, accelerated it, or had no effect.
The value of this case report is in describing a patient-centric multidimensional treatment plan for a challenging neuropathic ulcer. It introduces the possibility that laser therapy may become a beneficial addition to the wound care arsenal. This question requires further research on human wounds, especially wounds with etiologies other than venous insufficiency.
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