The effects of different laser doses on skin

Abstract

The laser-skin interaction was studied using the laboratory albino rat skin as an experimental sample and 10.6 μm wavelength CO 2 laser as a source of irradiation. This study aimed to determine the effect of different laser doses on the skin structure as a trial to understand how laser exerts its medical effects in treating skin problems. It also aimed to determine the relationship between the laser dose and biological effects and thus determine the lowest dose that had highest medical effects with lowest skin damage. Briefly, the rat skin was exposed to CW CO 2 laser at 12.5, 14.1, 15.6 and 17.2 W/cm 2 for 15 s. Directly after the exposure, biopsies of normal and exposed skin were preserved and fixed for histological studies. The images obtained from the compound light and electron microscopes exerted changes contributed to the interaction of the skin cells to the heat and energy produced by the continuous wave carbon dioxide (CW CO 2) laser during the exposure time. Basically, the tissue damage caused by the laser was mainly due to photothermal effect and increased gradually as the irradiation dose increased. Epidermal loss along with coagulation, homogenous hyalinization, lost of hair associated with shrinkage and collapse of hair follicle structures of varying depths at the-burn sites were detected in the histologic sections. Damage-power density (DPD) relationship was confirmed by measuring the damage depth using the software provided in the light microscope. On the other hand, Scanning electron microscopy (SEM) showed detailed images of the extensive epidermal epithelial cells damage which also increased by increasing the laser dose. Rough surface, partial destruction of intercellular junctions giving rise to loss of adherence between squamous cells and formation of narrow spaces between these cells were the most evident changes detected. The findings may help specialists to choose the best laser parameters for certain applications.

bFGF and collagen matrix hydrogel attenuates burn wound inflammation through activation of ERK and TRK pathway

“…The epithelium was well-formed but with low deposition of collagen fibres. Additionally, SEM images of control rat skin section showed smooth, intact and homogeneous skin surface which is similar to previous finding 16 whether; the morphology was changed in the untreated rat skin section as compared to the SEM image of the control rat skin (Fig. 2C).…”

Evaluation of Carbon Dioxide (CO2) Laser Incision Characteristics in A Viable Human Skin

“…During the use of CO 2 laser, it seems to be that the vaporization of intracellular water results in a thousand-fold expansion of cells, the production and explosive release of steam causes ablation of the biological tissue and the thermal energy is conducted to the deeper tissue planes produces a zone of permanent heat damage zone evidenced by protein denaturation. The volume or thickness of this zone is directly proportional to the power density of the laser at the superficial lased tissue interface as well as on the duration of laser energy exposure and this is agreed with [9,10,11]. The non-target adjacent tissue has radiant thermal energy histological changes consisting of a narrow zone of carbonized tissue, an underlying desiccated tissue necrosis zone, and a peripheral zone of edematous damaged tissue [12,13].…”

Simple Estimate of the Impact of M2 and Strehl Ratio on the Effective Focusable Spot Size

“…In the limiting case for which the laser-tissue interaction process is only driven by the applied dose (in the presence of tight pulse overlapping, average energy per unit of area) [18], the effects of M 2 and the SR vanish (since the reduction in intensity is compensated by the cumulative overlap effect) and the results are identical to those obtained under the diffraction-limited assumption.…”