Estudo clínico cego e randomizado sobre o efeito da fotobiomodulação e da terapia fotodinâmica na cicatrização de lesões crônicas

Abstract

Chronic wounds can be defined as those that do not advance in relation to the orderly tissue repair process and compromise anatomical integrity and tissue repair time. Neuropathic ulcers are chronic lesions and one of the most stigmatizing sequelae of diabetic foot and leprosy-associated wounds, their presence is quite impairing for the individual and can lead to deformation and/or amputation of the affected limb. For the treatment of these wounds, there are a variety of existing topical products, including hydrogel. Besides, treatment through the use of photobiomodulation therapy (PBM) and photodynamic therapy (PDT) has shown positive results in the repair process. Objective: To evaluate the effects of PBM and PDT with methylene blue, associated or not with urea, on the healing of chronic wounds caused by diabetes and leprosy. Methodology: This is a blind randomized clinical trial. There were 17 volunteers with chronic diabetes wounds that were divided into 4 groups: Group I hydrogel with alginate (n=3), Group II PBM with diode laser λ= 660 nm, power of 100 mW, with 4J applied every 1 cm (n=6), Group III PDT with methylene blue at 100 µM associated with red emission diode laser λ = 660 nm, power of 100 mW with 9 J every 1 cm (n=5), and Group IV methylene blue 100 µM PDT associated with 2M urea (n=4) and the same irradiation parameters as G III. And 13 volunteers with chronic leprosy lesions divided into 4 groups: Group I hydrogel with alginate (n=3); Group II PBM with diode laser λ= 660 nm, power of 100 mW, with 4J applied every 1 cm (n=4) ; Group III PDT with methylene blue at 100 µM associated with red emission diode laser λ = 660 nm, power of 100 mW with 9 J every 1 cm (n=3) and Group IV PDT with methylene blue at 100 µM associated with 2M urea and the same irradiation parameters as G III. For the intervention protocol, the volunteers underwent 8 sessions, comprising 2 sessions a week, on alternate days. Photographic records were used for the macroscopic evaluation throughout the sessions and the measurement of the wound was related to the greatest length versus the greatest width. For all groups, the Pressure Ulcer Scale for Healing (PUSH), was applied to assess the healing process. Results: This study found that diabetic individuals undergoing hydrogel therapy (G I) did not present a reduction in chronic wound size. As measured by the PUSH score, it was not statistically significant (p value = 0.317). However, it was observed that there was a significant reduction in the size of the 9 chronic lesion measured by the PUSH Score between days 1 and 8 in individuals with diabetes for groups G II (p<0.001), G III (p=0.004) and G IV (p=0.001). It was found that in individuals with leprosy undergoing hydrogel therapy, the reduction of chronic wound, measured by the PUSH score, was not statistically significant (p value = 0.096). However, it was observed that there was a significant reduction in the size of the chronic lesion measured by the PUSH score between days 1 and 5 in individuals with leprosy for G II (p value = 0.021), G III (p value = 0.005 ) and G IV PDT+AM 100 µM associated with 2M urea (p value = 0.034). Conclusion: The therapies with PBM and PDT with methylene blue, and PDT with methylene blue associated with urea reduce the size of the chronic wound in diabetic patients, requiring 3 applications. All light therapies evaluated in the study reduced the size of chronic wounds in leprosy patients after five applications.