Wound Dressing Transillumination

Photomed Laser Surg. 2009 Oct 9. [Epub ahead of print]

Analysis of Low-Level Laser Radiation Transmission in Occlusive Dressings.

de Jesus Guirro RR, de Oliveira Guirro EC, Martins CC, Nunes FR.

1 Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, School of Medicine of Ribeirão Preto, University São Paulo , Brazil .

Abstract Objective: The purpose of this study is to analyze the power transmitted by low-level laser therapy (LLLT) into occlusive dressings using different wavelengths for the treatment of cutaneous lesions. Background Data: LLLT has been largely used to treat several cutaneous lesions commonly associated with occlusive dressings to accelerate the healing process. Materials and Methods: Radiation transmission was measured by a digital power analyzer connected to a laser emitter with wavelengths of 660, 830, and 904 nm and mean levels of 30, 30, 6.5 mW, respectively, previously calculated. Thirteen different occlusive dressings were analyzed and interposed between the laser emitter and the power analyzer sensor, with 15 measurements made for each dressing. Statistics were provided by the analysis of variance (ANOVA), followed by Student’s t-test (p < 0.05). Results: The power transmitted ranged between 98.6% and 0%, depending on the material and wavelength. The dressings tested were BioFill, Hydrofilm, Confeel Plus 3533, Confeel 3218, DuoDERM Extra Thin, Hydrocoll, Micropore Nexcare, CIEX tape, Emplasto Sábia, CombiDERM, Band-aid, Actisorb Plus, in addition to polyvinylchloride (PVC) film, and transmitted power higher than 40% of the incident power, independently from the wavelength indicated for the association with LLLT. Conclusion: The results showed that LLLT transmission depends on the occlusive dressing material and the wavelength irradiated.

J Clin Laser Med Surg. 2000 Oct;18(5):235-40.

Low-level laser therapy for wound healing: feasibility of wound dressing transillumination.

Lilge L, Tierney K, Nussbaum E.

Photonics Research Ontario, Toronto, Canada. Llilge@ociautoronto.ca

OBJECTIVE: The purpose of this study was to assess the feasibility of exposing wounds during low-level laser therapy (LLLT) by transillumination of the wound dressings.

BACKGROUND DATA: LLLT has been associated with accelerated wound healing in chronic ulcers. The usual approach is to remove wound dressings prior to exposure and to treat three to five times weekly. Frequent change of wound dressings is time consuming and costly; it disrupts the healing process, increases the risk of wound infection, and may be traumatic for the patient.

METHODS: A double integrating sphere setup was employed to quantify the diffuse transmittance and reflectance of various wound dressings. Differences in transmittance for large area sources and point sources were demonstrated through the use of a diode laser and an incoherent light source.

RESULTS: There were a number of gels and membrane style wound dressings with diffuse transmittance of more than 50%. Hence, for these dressings the prescribed radiant exposure to the wound surface could be achieved by increasing the exposure duration, while maintaining reasonable overall treatment times.

CONCLUSIONS: Although LLLT by transillumination of wound dressings is feasible for a variety of wound dressings without significant commitments in additional treatment time, the specific transmission of products not included in this study needs to be determined at the intended treatment wavelength. A transillumination approach may facilitate a faster rate of wound healing than LLLT applied to exposed wounds by reducing trauma and the risk of infection.