Fluorescence spectroscopy as a tool to detect and evaluate glucocorticoid-induced skin atrophy

Topical glucocorticoid (GC) therapy has been successfully used in the treatment of several common cutaneous diseases in clinical practice for a long time, and skin atrophy is one of the most typical cutaneous side effects of this therapy. The aim of this study was to evaluate the potential of noninvasive fluorescence spectroscopy (FS) technique in the detection and classification of GC-induced skin atrophy. A total of 20 male Wistar rats were used in the experimental protocol under controlled environmental conditions and with free access to food. One group received topical application of clobetasol propionate 0.05% for 14 days to induce cutaneous atrophy (atrophic group) and the other (control) group received only vehicle application following the same protocol and schedule. Histological analyses and FS measurements with laser excitation at both 532 nm and 408 nm were obtained on days 1 and 15. The FS results were classified as "normal" or "atrophic" according by histological analysis. Fluorescence spectra obtained with excitation at 408 nm allowed a clear distinction between the control and atrophic groups, and were more informative than the those obtained at 532 nm. Our results reveal that, if correctly applied, FS allows noninvasive evaluation of corticosteroid-induced skin atrophy, and thus represents an important step towards better monitoring of undesirable side effects of cutaneous therapy.     

Efficacy of fractional CO<Subscript>2</Subscript> laser in treatment of atrophic scar of cutaneous leishmaniasis

Cutaneous leishmaniasis is an endemic disease in Iran. Unfortunately, it can lead to unsightly atrophic scars with limited treatment options. Fractional CO₂ laser is accepted for treatment of atrophic acne scars and recently has been used to treat cutaneous leishmaniasis, so we planned to use fractional CO₂ laser on leishmaniasis scar. We conducted this study on 60 leishmaniasis scars on the face of 40 patients. The lesions were treated by a fractional CO₂ laser with beam size of 120 μm, with energy of 50–90 mJ, and 50–100 spots/cm² density with two passes in three monthly sessions. Evaluation was done in the first and second months after the first treatment and 3 and 6 months after the last treatment. Digital photography was performed at each visit. Assessment of improvement rate by patient and physician was rated separately as follows: no improvement (0 %), mild (<25 %), moderate (25–50 %), good (51–75 %), and excellent (76–100 %). Based on patients’ opinion, in the first and second follow-up, 48.3 and 90 % of them reported moderate to excellent healing, respectively (p?<?0.001). In 3 and 6 months follow-up after the end of the experiment, most of the patients (88.3 and 95 %, respectively) reported moderate to excellent healing of scars. Based on two observers’ opinion, healing in the first follow-up in most of the patients (65 %) was mild to moderate and 33 % were reported as having no healing. In the second follow-up, only 5 % of the patients were reported with no healing and 60 % were reported as having moderate healing (p?<?0.001). In 3 and 6 months follow-up, most of the patients (95 and 96.6 %) were reported as having moderate to excellent healing (p?=?<0.001). Our results underlined the high efficacy of fractional CO₂ laser for leishmaniasis scar. No significant adverse effects were noted.     

Laser biostimulation of wound healing: bioimpedance measurements support histology

Laser biostimulation in medicine has become widespread supporting the idea of therapeutic effects of photobiomodulation in biological tissues. The aim of this study was to investigate the biostimulation effect of laser irradiation on healing of cutaneous skin wounds, in vivo, by means of bioimpedance measurements and histological examinations. Cutaneous skin wounds on rats were subjected to 635 nm diode laser irradiations at two energy densities of 1 and 3 J/cm² separately. Changes in the electrical properties of the wound sites were examined with multi-frequency electrical impedance measurements performed on the 3rd, 7th, 10th, and 14th days following the wounding. Tissue samples were both morphologically and histologically examined to determine the relationship between electrical properties and structure of tissues during healing. Laser irradiations of both energy densities stimulated the wound healing process. In particular, laser irradiation of lower energy density had more evidence especially for the first days of healing process. On the 7th day of healing, 3 J/cm² laser-irradiated tissues had significantly smaller wound areas compared to non-irradiated wounds (p?<?0.05). The electrical impedance results supported the idea of laser biostimulation on healing of cutaneous skin wounds. Thus, bioimpedance measurements may be considered as a non-invasive supplementary method for following the healing process of laser-irradiated tissues.     

Hereditary haemorrhagic telangiectasia treated by pulsed neodymium:yttrium-aluminium-garnet (Nd:YAG) laser (1,064 nm)

Hereditary haemorrhagic telangiectasia (HHT) is a familial, autosomal, dominant, multi-system, vascular, dysplasia. Besides repetitive epistaxis, cutaneous eruptive macules and nodules lead to recurring bleeding and cosmetic problems. We report on a pilot study of four cases of HHT in which cutaneous lesions were treated with a pulsed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1,064 nm). Pulsed Nd:YAG laser treatment, without anaesthesia, was performed several times on eruptive angiomas on palmar and facial skin. Lesions on fingers and face mostly showed very good, or even complete, clearing after the first laser treatment. Several macules required multiple treatment; only a few lesions showed no effect. Pulsed Nd:YAG laser therapy (1,064 nm) appears to be an effective and safe treatment option for hereditary haemorrhagic telangiectasia on the skin of face and extremities.     

Comparative analysis of low-level laser therapy (660 nm) on inflammatory biomarker expression during the skin wound-repair process in young and aged rats

The wound-healing process plays an essential role in the protective response to epidermal injury by tissue regeneration. In the elderly, skin functions deteriorate as a consequence of morphological and structural changes. This study aimed to evaluate and compare the effect of low-level laser therapy (LLLT) in cutaneous wound healing in young and aged rats. A total of 60 male rats comprising 30 young (±30 days) and 30 aged (±500 days) was used. The animals were divided into four experimental groups and underwent skin wound and/or treatment with LLLT (660 nm, 30 mW, 1.07 W/cm², 0.028 cm², 72 J/cm², and 2 J). Analyses were conducted to verify the effects of LLLT in the tissue repair process, in the gene expression, and protein expression of TNF-α, IL-1β, and IL-10, obtained in skin wound model. Results showed that there were significant differences between the young control group and the aged control group and their respective treated groups (LLLT young and LLLT aged). We conclude that LLLT has shown to be effective in the treatment of skin wounds in young and aged animals at different stages of the tissue repair process, which suggests that different LLLT dosimetry should be considered in treatment of subjects of different ages. Further clinical trials are needed to confirm these findings in clinical settings.     

Acne vulgaris

Acne vulgaris is a common inflammatory skin condition that presents management difficulties to cosmetic surgeons. Acute management and treatment focuses on early diagnosis as well as treatment with topical agents, oral antibiotics, hormonal therapy,and nonablative chemical peel and laser applications. The treatment of postinflammatory scarring must be individualized to address potential macular dyschromia, cystic lesions,epithelial bridges, or deep pitted scars. A review of interventional options is presented to apply to the spectrum of acne scarring as well as a review of the literature to address objectively published reports on efficacy.     

Oral mucosa response to laser patterned microcoagulation (LPM) treatment. An animal study

In this study a minimally invasive microsurgical approach was used for laser patterned microcoagulation (LPM) to initiate gingival and oral mucosal tissue regeneration. We performed a feasibility assessment and histological examination of laser damage and regeneration in the gingiva and oral mucosa using an animal model. The study animals comprised 18 healthy rabbits which were treated in vivo with single pulses from a diode laser at a wavelength of 980 nm and a power of up to 20 W applied to the gingival and oral mucosa at multiple time points. Biopsies were stained with hematoxylin and eosin, nitroblue tetrazolium chloride and picrosirius red, and evaluated by two pathologists blinded to the parameters and date of laser exposure. Histological analysis revealed that the continuity of the epithelial basal cell layer had been reestablished by 1–2 days after LPM, and complete epithelial regeneration had occurred by 7–12 days. A pronounced reactive inflammation developed in the column area 1 day after treatment. High activity of fibroblasts producing new collagen participated in the formation of a network of new thin-wall blood vessel. By the 28th day the tissue structure was almost completely restored with a similar increase of vascularity, and there were no signs of scarring. By the 90th day, tissue structure was completely restored, indicating complete healing. A single LPM treatment induces a wound healing response in the oral mucosa, showing the potential of LPM for the initiation of oral mucosa and gingival regeneration. Complete healing observed in 3 months after treatment with no keratinization change or scar tissue formation.     

Treatment of superficial vascular lesions with the KTP 532-nm laser: experience with 647 patients

Superficial vascular lesions are a common dermatological diagnosis but are often difficult to treat. Numerous lasers (especially the dye laser) and intense pulsed light sources have been used, but there have been very few reports on the effectiveness of the potassium-titanyl phosphate (KTP) laser. We have extensive experience of this modality at our institution, and the purpose of this survey is to report on the safety and efficacy of the KTP laser. Using an in-house database, we retrospectively collected data from patients who had undergone treatment with the KTP laser for superficial vascular lesions. Patients of Fitzpatrick skin type I–IV were included. Exclusion criteria were Fitzpatrick skin type V, patients with obvious suntan and those on potentially phototoxic medications or minocycline therapy. Diagnoses included discrete or matted telangiectasia, strawberry naevus, spider angioma, rosaceal erythema, rosaceal telangiectasia, telangiectatic naevus, angioma, combined rosaceal erythema/telangiectasia, port-wine stain, venous lake haemangioma and hereditary haemorrhagic telangiectasia. Patients underwent an initial test treatment and further treatment at 6-week intervals as required. Clinical photographs were taken pre- and post-treatment, and outcome was graded by patient and physician. Adverse effects were recorded including scarring, hypo- or hyperpigmentation, marked swelling, blistering, scabbing and bruising. Six hundred forty-seven patients with 13 diagnoses on 9 different body sites were recorded. Four hundred eighty-six were female, and the median age was 39.5 years. Of the lesions treated, 33.7 % (n?=?218) were discrete telangiectases and 31.8 % (n?=?206) were spider angiomas. A 92.7 % of lesions were on the face. Four hundred thirteen (77.6 %) patients who had outcomes recorded at 6 weeks were graded as “clearance” or “marked improvement”. Only 38 (5.8 %) patients experienced adverse effects, all of which were minor; the main adverse effect was swelling. Unlike the dye laser, there was only one case of bruising out of 647 patients. This is the largest survey of patients to have undergone KTP laser treatment reported in the literature. Our results show that the KTP laser is a safe and effective modality for the treatment of superficial vascular lesions.     

Evaluation of corticosterone and IL-1β, IL-6, IL-10 and TNF-α expression after 670-nm laser photobiomodulation in rats

The literature has shown that low-level laser therapy accelerates the repair of cutaneous wounds. However, there is a scarcity of scientific studies that characterise the possible systemic interference of laser photobiomodulation. The aim of this research was to quantitatively evaluate blood corticosterone levels and tissue cytokine expression in cutaneous wounds of rats treated with low-level laser therapy (semiconductor diode AsGaAl, continuous emission, 9 mW, 670 nm, 0.031 W/cm², beam with an output area of 0.28 cm²) and normal controls. A total of 36 male Wistar rats were used and randomly divided into two groups of 18 rats each. A standardised circular 6-mm-diameter wound was made in the dorsal skin region of each rat, and they were euthanised at 1, 6 and 12 h after cutaneous surgery. The blood was collected, and portions of cutaneous tissue and subcutaneous muscle were removed and cryopreserved. Corticosterone levels in the blood were measured by a radioimmunoassay technique; histological sections were submitted to the ELISA technique for analysis of tissue cytokine expression levels. At 6 h after surgery, a significant increase in corticosterone and a significant reduction in the levels of IL-1β and IL-6 in tissues of irradiated wounds were observed when compared to controls (p?<?0.05). The levels of TNF-α and IL-10 expression were not significantly different between the groups at different time intervals. Thus, this study strongly suggests a systemic and local biomodulation of low-level laser therapy as indicated by the blood levels of corticosterone and the tissue expression of IL-1β and IL-6, respectively.     

Clinical and histologic effects from CO2 laser treatment of keloids

Keloids and hypertrophic scars are abnormal responses to wound healing. In general, keloids exhibit a proliferative growth beyond the margins of the scar and remain persistent; while hypertrophic scars are contained to the original wound and may regress over time. In particular, keloid formation is one of the most challenging clinical problems, with increasing frequency in surgical practice. Many treatments are available such as intralesional corticosteroids, topical applications, cryotherapy, surgical excision, radiation therapy, silicone gel sheeting, pressure therapy, and laser therapy. There are no set guidelines for the treatment of keloids and the most common treatments are individualized and depended on the distribution, size, thickness, and consistency of lesions. The authors have evaluated carbon dioxide laser successfully in the treatment of keloids and the aim of this study was to determine the immediate and long-term histologic and clinical effects of keloids after carbon dioxide laser. Fifty consecutive patients (40 females, 10 males, ages 18–60 years, mean age 40 years) with moderate to severe keloids were evaluated. All the patients received regional treatments (deltoid, elbow, chin, and ear) in an outpatient setting with a high-energy pulsed CO₂ laser. Significant immediate and prolonged clinical improvement in skin tone, texture, and appearance of carbon dioxide laser was examined in all patients. Dermal remodeling was observed also on histologic examination of biopsied tissue after treatment. Carbon dioxide laser appears to be effective and well tolerated for the treatment of keloids, avoiding the adverse effects and lengthy recovery time.     

Effects of low level laser therapy on the prognosis of split-thickness skin graft in type 3 burn of diabetic patients: a case series

Significant populations in burn centers are diabetic burn patients. Healing process in these patients is more difficult due to diabetes complications. The gold standard treatment for patients with grade 3 burn ulcer is split-thickness skin grafting (STSG), but in the diabetic patients, the rate of graft failure and amputation is high due to impaired tissue perfusion. The technique of low level laser therapy (LLLT) improves tissue perfusion and fibroblast proliferation, increases collagen synthesis, and accelerates wound healing. The purpose of this case report is introducing a new therapeutic method for accelerating healing with better prognosis in these patients. The protocols and informed consent were reviewed according to the Medical Ethics, Board of Shahid Beheshti Medical Sciences (IR.SBMU.RAM.REC.13940.363). Diabetic type 2 patients with 13 grade 3 burn ulcers, candidate for amputation, were enrolled in the study. We used a 650-nm red laser light, 2 J/Cm for the bed of the ulcer and an 810-nm infrared laser light 6 J/Cm² for the margins along with intravenous laser therapy with a 660-nm red light, before and after STSG for treating grade 3 burn ulcers in 13 diabetic ulcers. The results of this study showed complete healing in the last 8 weeks for all patients who were candidates for amputation. In this case series, we present 13 cases of diabetic ulcer with type 3 burn wound, candidate for amputation, who healed completely using LLLT and STSG. This is the first time that these two techniques are combined for treatment of burn ulcer in diabetic patients. Using LLLT with STSG might be a promising treatment for burn victims especially diabetic patients.     

Platelet‐rich plasma for resistant oral erosions of pemphigus vulgaris: A pilot study

Oral erosions and ulcers of pemphigus vulgaris (PV) are a debilitating condition that is usually difficult to treat. The wound healing properties of platelet‐rich plasma (PRP) encouraged us to evaluate its usefulness in treatment of non‐healing oral PV lesions. Seven patients with chronic oral PV, resistant to conventional therapy, were treated with weekly to monthly injections of PRP of affected mucosal membranes. All recruits reported improvement in pain and mastication and 6 of 7 patients had an improvement in pemphigus disease area index scores with PRP treatment. PRP injections seems to accelerate the healing process and decrease the pain and eating discomfort associated with the oral erosions and ulcers induced by PV.     

The advantages of carbon dioxide laser applications in paediatric oral surgery. A prospective cohort study

The aim of this study is to evaluate and demonstrate the advantages of the carbon dioxide laser in paediatric oral surgery patients in terms of less post-operative complications, healing without scaring, functional benefits, positive patient perception and acceptance of the treatment. One hundred fit and healthy paediatric patients (aged 4–15 years) were recruited to undergo laser surgery for different soft tissue conditions. The outcome of these laser treatments was examined. The Wong-Baker Faces Pain Rating Scale was employed to evaluate the pain before, immediately after laser treatment in the clinic and 1 day after post-operatively at home. Post-operative complications and patients’ perception and satisfaction were self-reported during a review telephone call the day after treatment. The patients were reviewed 2 weeks after surgery. Laser parameter was 1.62 W, measured by power meter, continuous wave mode with 50 % emission cycle. The beam spot size at the target tissue was 0.8 mm. The pain score pre-operative, during and immediately after laser treatment was rated 0. Whilst the pain score 1 day after surgery was rated between 0 and 2, the healing time was measured over 2 weeks. None of the patients reported post-operative complications after surgery. Patients’ perception and acceptance were rated very good. Laser dentistry is a promising field in modern minimally invasive dentistry, which enables provision of better care for children and adolescents. In this cohort study, the use of the carbon dioxide laser therapy offers a desirable, acceptable and minimally invasive technique in the surgical management of soft tissues in paediatric oral surgery with minimal post-operative complications.     

The influence of red laser irradiation timeline on burn healing in rats

Low-level laser therapy (LLLT) promotes biomodulation of wound healing and literature reports that light delivery during the inflammation could play a different role compared with latter phases of the healing process. The objective of this study was to investigate whether single dose of a red laser (λ?=?660 nm) is different from fractionated delivery protocol in full thickness burns. Two lesions were inflicted on the back of 36 rats. In the fractionated dose group (FG), the lesions were irradiated with 1 J/cm² on days 1, 3, 8, and 10 post-wounding. In the single dose group (SG), the lesions were irradiated with 4 J/cm² on day 1, immediately after injury. Control lesions (CG) received no light and were left to heal spontaneously. Blood flow was measured on days 1, 3, 8, 10, 15, and 21 using laser Doppler flowmetry. Animals were killed on days 3, 8, 10, 15, and 21. Skin specimens were obtained and routinely processed for hematoxylin and eosin. The specimens were evaluated according to differential leukocyte counting and angiogenesis. Statistical analysis was performed, and significance was accepted at p?<?0.05. Irradiated groups showed a peak of new vessels on day 15 while, for CG, the peak was on day 21. On day 21, FG exhibited a significantly greater number of cumulative neutrophils while SG showed a higher number of mononuclear cells. Our results confirm that both protocols used accelerate angiogenesis and stimulate leukocyte chemotaxis on burn treatment. In addition, this work suggests that a single-dose LLLT accelerates the inflammatory phase of skin repair.     

Photobiomodulation of wound healing via visible and infrared laser irradiation

Fibroblast cells are known to be one of the key elements in wound healing process, which has been under the scope of research for decades. However, the exact mechanism of photobiomodulation on wound healing is not fully understood yet. Photobiomodulation of 635 and 809 nm laser irradiation at two different energy densities were investigated with two independent experiments; first, in vitro cell proliferation and then in vivo wound healing. L929 mouse fibroblast cell suspensions were exposed with 635 and 809 nm laser irradiations of 1 and 3 J/cm² energy densities at 50 mW output power separately for the investigation of photobiomodulation in vitro. Viabilities of cells were examined by means of MTT assays performed at the 24th, 48th, and 72nd hours following the laser irradiations. Following the in vitro experiments, 1 cm long cutaneous incisional skin wounds on Wistar albino rats (n = 24) were exposed with the same laser sources and doses in vivo. Wound samples were examined on 3rd, 5th, and 7th days of healing by means of mechanical tensile strength tests and histological examinations. MTT assay results showed that 635 nm laser irradiation of both energy densities after 24 h were found to be proliferative. One joule per square centimeter laser irradiation results also had positive effect on cell proliferation after 72 h. However, 809 nm laser irradiation at both energy densities had neither positive nor negative affects on cell viability. In vivo experiment results showed that, 635 nm laser irradiation of both energy densities stimulated wound healing in terms of tensile strength, whereas 809 nm laser stimulation did not cause any stimulative effect. The results of mechanical tests were compatible with the histological evaluations. In this study, it is observed that 635 nm laser irradiations of low energy densities had stimulative effects in terms of cell proliferation in vitro and mechanical strength of incisions in vivo. However, 809 nm laser irradiations at the same doses did not have any positive effect.     

Lasers for cutaneous congenital vascular lesions: a comprehensive overview and update

The use of laser to treat cutaneous lesions began with Dr. Leon Goldman and his coworkers in 1963. Ten years later, these authors described promising effects on angiomas using the continuous-wave neodymium:yttrium–aluminum–garnet laser. In 1983, Anderson et al. proposed the photothermolysis theory. The selective destruction of vascular lesions is based on this principle, and it is still a guide for treatment of vascular lesions. Over the past 25 years, laser treatment of cutaneous vascular lesions has progressed significantly. Vascular lasers such as argon, tunable dye, krypton, and copper vapor were used in the past and were associated not only with risk of scarring but also hyper- and hypopigmentation. Since then, new devices were developed in order to minimize these side effects. This article presents an overview and update of the current available treatment of cutaneous vascular lesions and covers future directions for vascular laser technology.     

Clinical assessment of the efficacy of photodynamic therapy in the treatment of oral lichen planus

The study objective was clinical assessment of the efficacy of photodynamic therapy (PDT) in the treatment of oral lichen planus (OLP). There were 23 patients aged 31–82 included in the study with oral lichen planus diagnosed clinically and histopathologically. In all patients photodynamic therapy was performed with the use of chlorin e6 (Photolon^®), containing 20 % chlorin e6 and 10 % dimethyl sulfoxide as a photosensitizer. PDT was performed using a semiconductor laser, with power up to 300 mW and a wavelength of 660 nm. A series of illumination sessions was conducted with the use of superficial light energy density of 90 J/cm². Changes of lesion size were monitored at one, two, five, and ten PDT appointments from the series of ten according to the authors' own method. The sizes of clinical OLP lesions exposed to PDT were reduced significantly (on average by 55 %). The best effects were observed for the lesions on the lining mucosa (57.6 %). The therapy was statistically significantly less effective when masticatory mucosa was affected (reduction, 30.0 %). Due to substantial efficacy and noninvasiveness, PDT can be useful in the treatment of OLP lesions.     

Cutaneous verrucous carcinoma.

Verrucous carcinoma is a rare, low-grade, well-differentiated squamous cell carcinoma most commonly seen on mucosa. It has been infrequently reported to occur on the skin, where it is a slow-growing and locally aggressive tumour. It is not uncommon for cutaneous verrucous carcinomas to be mistaken for the more frequent verruca vulgaris and treated accordingly. Three cases of cutaneous verrucous carcinoma are presented with the medical history and follow-up data. Surgery is the treatment of choice; these lesions may sustain a potentially anaplastic transformation after radiation therapy.     

Effect of low-level laser therapy on the fracture healing process

Low-level laser therapy (LLLT) is a biophysical form of intervention in the fracture-repair process, which, through several mechanisms, accelerates the healing of fractures and enhances callus formation. The effect of laser on fracture healing is controversial. Some authors affirm that LLLT can accelerate bone formation by increasing osteoblastic activity. The objective of our study was to evaluate the effect of laser therapy on fracture healing. Thirty rabbits were subjected to tibial bone open osteotomies that were stabilized with external fixators. The animals were divided into two study groups: laser group and control group. Callus development and bone mineral density were quantitatively evaluated by CT; the animals were then killed and the fractures were assessed for biomechanical properties. The results demonstrated that the increasing rate of bone mineral density was higher in the laser (L) group than in the control (C) group. CT at 5 weeks revealed a mean callus density of 297 Hounsfield units (HU) for the control group and 691 HU for the L group, which was statistically significant (P?=?0.001). In the L group, the mean recorded fracture tension was 190.5 N and 359.3 N for healed and intact bones, respectively, which was statistically significant (P?<?0.001). The result of the study showed that the use of laser could enhance callus development in the early stage of the healing process, with doubtful improvement in biomechanical properties of the healing bone; therefore, laser therapy may be recommended as an additional treatment in non-union fractures in humans.     

Photobiomodulation therapy action in wound repair skin induced in aged rats old: time course of biomarkers inflammatory and repair

Previous studies have discussed an inverse correlation between age and wound healing, because it relates to the association of aging with a gradual decrease in healing capacity. Treatment with photobiomodulation therapy (PBMT) improves wound healing by inducing increases in mitotic activity, numbers of fibroblasts, collagen synthesis, and neovascularization. Therefore, this study aimed to evaluate the effects of PBMT in cutaneous wound healing in aged rats. A punch biopsy of 8 mm in diameter was performed to produce a skin wound. The study included 45 male rats, of which 15 were young (30 days) and 30 were elderly (500 days). The 45 animals were distributed into 3 experimental groups, which were subjected to skin wounds and 1 aged group received PBMT, with a 30-mW laser beam (power density of 1.07 W/cm²), beam area of 0.028 cm², and λ660 nm produced through active phosphide Gallium-Aluminum-Indio (InGaAIP). The PBMT application took the form of a single-point transcutaneous method, with a total energy of 2 joules per wound site, energy density of 72 J/cm², and time of 1 min and 7 s. Analysis was performed to verify the effect of PBMT on the quantity of collagen I and III, metalloproteinase 3 and 9 (MMP-3 and MMP-9), tissue inhibitor of metalloproteinase-2 (TIMP-2) and of vascular endothelial growth factor (VEGF) at the wound site by immunohistochemistry, cytokine-induced neutrophil chemoattractant (CINC)-1, by enzyme-linked immunosorbent assay (ELISA) and interleukin (IL)-6 real-time polymerase chain reaction (RT-PCR). That we conclude LLLT is effective in the modulation of inflammatory mediators IL-6, CINC-1, VEGF, MMP-3, MMP-9 and TIMP-2 as well as increased collagen production in aged animals during different phases of the tissue regeneration process. However, the effects of PBMT obtained in the aged animals (aged LLLT group) suggest that new dosimetries should be tested to achieve better results.