Lasers, lights and related technologies: a review of recent journal highlights.
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Humans↗
Biomedical subjects
R J Barlow
Publications and source records attributed to R J Barlow.
Laser remodelling of nodular nasal lupus pernio.
Disfiguring nodular nasal lupus pernio is a rare condition that responds poorly to medical management. We have treated three affected patients with carbon dioxide laser remodelling, and report their progress 6 years, 2 years and 16 months following treatment, respectively. Although the abnormal granulomatous tissue was debulked rather than completely excised, the wounds healed within 4 weeks in all patients. The cosmetic results are acceptable and have been maintained in two of the patients, perhaps a reflection of their overall systemic sarcoidosis control.
Carbon Dioxide↗
Eyelid sebaceous gland carcinoma (SGC) treated with 'slow' Mohs' micrographic surgery.
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Chalazion↗
Topical imiquimod immunotherapy in the management of lentigo maligna.
Melanoma in situ of the lentigo maligna (LM) type is a precursor lesion of LM melanoma. It most commonly occurs in elderly individuals, on the head and neck. Although surgical excision is recommended, this may not be practical for large lesions at cosmetically sensitive sites. In addition, histological changes commonly extend beyond the clinical margins of the lesion. This study describes the use of imiquimod 5% cream as topical immunotherapy in the management of lentigo maligna. Twelve patients (average age 63 years, 10 female), of biopsy-proven facial LM were treated with topical imiquimod, three times a week for 6 weeks. In the absence of an inflammatory response, patients were asked to apply the treatment daily. Seven showed clearance of the LM clinically and histologically. A further three patients showed clearance histologically with persisting pigmentation due to dermal melanin and melanophages. Thus, 10 of 12 patients cleared with no relapse after a median follow-up of 6 months. Two patients failed to respond to imiquimod and their lesions were treated with surgical excision. Imiquimod was well tolerated, except in three patients who experienced an intense inflammatory response. Two of these also developed secondary infection. Imiquimod 5% cream appears to offer a potential noninvasive method for the treatment of lentigo maligna.
Adjuvants, Immunologic↗
Treatment of Darier's disease with photodynamic therapy.
BACKGROUND: Photodynamic therapy (PDT) using topical 5-aminolaevulinic acid (5-ALA) as a photosensitizer has been reported in the treatment of both neoplastic and benign cutaneous disorders. OBJECTIVES: To evaluate the efficacy of photodynamic therapy in selected patients with Darier's disease (keratosis follicularis). METHODS: Six patients with Darier's disease were assessed before and after treatment with PDT using 5-ALA and mean fluence rates of 110-150 mW cm-2. RESULTS: Of the six patients, one was unable to tolerate the treatment. Of the remaining five, all experienced an initial inflammatory response that lasted two to three weeks. In four of the five patients, this was followed by sustained clearance or improvement over a followup period of six months to three years. Three of these four patients were on systemic retinoids and the fourth had discontinued acitretin prior to PDT. In the fifth patient partial improvement was followed by recurrence after etretinate therapy was discontinued. Biopsy specimens taken immediately after the procedure in two patients demonstrated a mild inflammatory cell infiltrate in the dermis. A biopsy obtained eighteen months after PDT from a successfully treated area showed no signs of Darier's disease and a subtle increase of collagen in the upper dermis. CONCLUSIONS: Photodynamic therapy can be viewed as a potential adjunctive modality for Darier's disease but should not be considered as a substitute for retinoids in patients who require systemic treatment.
Adult↗
On dermatological surgery, registrars and residents.
Training in aspects of skin surgery is now a requirement of general dermatology registrars and residents in the UK and USA, respectively. We compare this component of the training programmes at St John's Institute of Dermatology in London and at New York Medical College in New York City. Because of their understanding of cutaneous pathology, dermatologists are often best qualified to assess patients for skin procedures and should therefore be involved, directly or indirectly, in their surgical management. In our view, the curricula should be changed to place more emphasis on the supervised assessment and treatment of patients with skin tumours as well as to reflect the growing importance of laser treatments and the demand by patients for cosmetic interventions.
Dermatology↗
U.K. guidelines for the management of cutaneous melanoma.
These guidelines for management of cutaneous melanoma present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation. To reflect the collaborative process for the U.K., they are subject to dual publication in the British Journal of Dermatology and the British Journal of Plastic Surgery.
Biopsy↗
Mohs' micrographic surgery using frozen sections alone may be unsuitable for detecting single atypical melanocytes at the margins of melanoma in situ.
BACKGROUND: It remains questionable whether micrographic surgery with frozen sections is an appropriate technique for excision of melanoma in situ (MIS) of the lentigo maligna type. Advocates of the technique have interpreted MIS as being histologically defined by nests and contiguous atypical melanocytes on the basal layer. Others, however, have viewed the periphery of MIS as consisting of scattered single atypical melanocytes, a finding that may be difficult or impossible to establish on frozen sections. OBJECTIVES: To examine the reliability of micrographic surgery using frozen sections interpreted by an experienced Mohs' surgeon, in the excision of MIS. METHODS: From a total of 154 specimens, frozen sections from the 50 specimens with margins that were considered difficult to interpret were thawed, sent for routine processing and then examined 'blind' by a dermatopathologist. RESULTS: Using the dermatopathologist's report on paraffin-embedded sections as a reference point, the sensitivity and specificity of frozen sections were calculated to be 59% and 81%, respectively. CONCLUSIONS: Using these histological criteria, micrographic surgery with frozen sections alone is unreliable in the excision of MIS.
Adult↗
Nonablative laser resurfacing: a systematic review of the literature.
'Nonablative laser resurfacing' is a new treatment for photoaged skin, the aim of which is to wound the upper dermis in order to induce dermal fibrosis and improve the clinical appearance. Unlike conventional laser resurfacing or dermabrasion, the epidermis is protected and retained to avoid the problems associated with open wounds and reepithelialization. A number of lasers and light sources have been developed or adapted for this purpose.
Dermabrasion↗
UK guidelines for the management of cutaneous melanoma.
These guidelines for management of cutaneous melanoma present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation. To reflect the collaborative process for the UK, they are subject to dual publication in the British Journal of Dermatology and the British Journal of Plastic Surgery.
Biopsy↗
Hypertrophic scar formation following carbon dioxide laser ablation of plantar warts in cyclosporin-treated patients.
We present four renal transplant patients who developed hypertrophic scars following carbon dioxide laser ablation of recalcitrant plantar warts. All of the patients were on long-term treatment with cyclosporin, which we believe to be responsible. We discuss several possible mechanisms by which cyclosporin may influence wound healing and scarring.
Adult↗
Partial re-emergence of a port-wine stain following successful treatment with flashlamp-pumped dye laser.
We present a 49-year-old patient with a congenital superficial vascular malformation of port-wine stain (PWS) type which has partially re-emerged in the 2.5 years since it was almost completely obliterated with the flashlamp-pumped short pulse pulsed-dye laser (FPDL). This observation is discussed with respect to the possible pathogenesis of PWS, with particular reference to the underlying autonomic nerve supply. The latter would not be expected to respond to FPDL and may explain re-emergence of the lesion.
Female↗
Objective assessment of port-wine stains following treatment with the 585 nm pulsed dye laser.
Previous studies assessing the treatment of port-wine stains (PWS) with the 585 nm pulsed dye laser have relied on either subjective clinical assessment or in vivo measurement of skin colour alone. The aim of the present retrospective study was to develop an objective method of assessing available pre- and post-treatment photograph pairs. Port-wine stains depicted in photographs of 23 patients following six or more treatment sessions were assessed for changes in colour (DeltaH*) and PWS size by computer image analysis and were compared with a subjective assessment of PWS reduction by a "blinded" physician examining the same images. The post-treatment mean reduction in the PWS assessed by the physician was 39.7%. A global assessment score incorporating values of DeltaH* and PWS size by computer analysis showed a mean reduction of 12%, with a more significant correlation with the physician assessment (Spearman's rank correlation coefficient 0.627; P=0.001) than changes in size or colour alone.
Adolescent↗
Scanned continuous wave CO2 laser resurfacing: a closer look at the different scanning modes.
BACKGROUND: The immediate effects of CO2 laser resurfacing include tissue ablation and residual thermal damage. These laser-tissue interactions are shaped by parameters including fluence, dwell time, and number of passes. OBJECTIVE: To assess the vaporization depth and residual thermal damage following use of the "superficial" or "deep" scanning modes of a 40 W continuous wave CO2 laser using both frozen and paraffin sections. METHODS: Fourteen subjects were divided into two groups for test treatments in the right preauricular area with two passes of the laser. The "superficial" mode parameters were 10 mm2 scan, 200 mm lens, power 36 W, scan time 0.24 seconds, dwell time 0.22 msec, and fluence 5.5 J/cm2. The "deep" mode settings were 9 mm2 scan, 200 mm lens, power 18 W, scan time 0.64 seconds, dwell time 0.28 msec, and fluence 7.0 J/cm2. The deep mode has a greater pattern density than the superficial mode and also has a double pattern of exposure. Biopsies encompassing equal areas of treated and untreated skin were taken immediately postoperatively and processed with both frozen and paraffin-embedded techniques. RESULTS: Vaporization depth was similar in both scanning modes and by both tissue-processing techniques. On frozen sections, residual thermal damage was 20% greater in the deep mode than the superficial mode, but this was not a statistically significant difference. There was no significant difference between the two modes in the depth of thermal injury on paraffin sections. CONCLUSION: In keeping with theoretical expectations, vaporization depth was similar in both treatment groups. No significant difference in residual thermal damage could be demonstrated between the two modes. However, the results on frozen sections suggest that residual thermal damage may be greater in the deep mode than in the superficial mode. In addition, frozen sections may be more sensitive than paraffin sections in the detection of residual thermal damage following laser resurfacing.
Acne Vulgaris↗
A clinical and histologic comparison of electrosurgical and carbon dioxide laser peels.
BACKGROUND: A radiofrequency-controlled electrosurgical device (ESD) has been adapted for skin peeling. A high-voltage, low-amperage current converts an irrigant into an ionized vapor, causing molecular dissociation and superficial damage in adjacent tissue. OBJECTIVE: We compared the clinical and histologic effects of a scanning carbon dioxide (CO(2)) laser (ESC/Sharplan 40C) and the ESD (Visage Cosmetic Surgery System, Arthrocare). METHODS: This study was a matched clinical trial involving 9 subjects. Two strips (2 x 1 cm) of skin on the temple were alternately assigned to receive 2 passes with either the CO(2) laser (Silktouch mode, 260 handpiece, fluence 15 J/cm(2), 10 mm(2)) or the ESD (125 V = setting 4, 5 mm handpiece). Strips were wiped with moist gauze after the first pass, and 4-mm punch biopsy specimens were taken immediately and after 3 months. Clinical assessment of re-epithelialization, erythema, and hyperpigmentation was made at 1, 2, 4, and 12 weeks. RESULTS: Median erythema scores were significantly greater in skin treated with the CO(2) laser. Histologic examination showed greater epidermal loss and a significantly thicker zone of underlying thermal damage (average difference, 63 microm; 95% confidence interval, 40-87; P =.0002) in skin treated with the CO(2) laser compared with skin treated with the ESD. After 3 months, a band of superficial dermal fibrosis was thicker in skin treated with the CO(2) laser (average difference, 170 microm; 95% confidence interval, 69-271; P =.0075). CONCLUSION: Two passes with the ESD elicited a more superficial skin peel than the CO(2) laser. Despite minimal thermal damage, superficial dermal fibrosis was seen at 3 months in skin treated with the ESD.
Acne Keloid↗
Treatment of angiofibromas with a scanning carbon dioxide laser: a clinicopathologic study with long-term follow-up.
BACKGROUND: Facial angiofibromas in tuberous sclerosis have been managed with various treatment modalities, including carbon dioxide (CO(2)) laser resurfacing. OBJECTIVE: Our purpose was to perform a long-term clinicopathologic assessment of CO(2) laser treatment of angiofibromas. METHODS: This was a retrospective case review of 10 patients treated with a scanning CO(2) laser to flatten lesions. Baseline clinical photographs and those taken at 6, 12, and 24 months after the operation were assessed by a blinded observer. Patients also evaluated outcomes. Biopsy specimens taken immediately and at 4 months after the operation were reviewed. RESULTS: Three groups of patients were identified: the first comprised 2 patients with sustained excellent and good outcomes. A second group (3 patients) had excellent outcomes in the early and medium term but then demonstrated partial deterioration. The last group (5 patients) had a range of early results with invariably poor outcomes at 24 months. In contrast, patients' self-assessment at 24 months was good or excellent in 8 of 10 cases. All biopsy specimens taken immediately after the procedure demonstrated ablation extending into the papillary dermis. Residual angiofibromas were present in 6 biopsy specimens. At 4 months, all biopsy specimens showed a band of superficial dermal fibrosis, but distinguishing between this and adjacent angiofibromas was often difficult. Long-term side effects included 2 cases of subtle hypopigmentation. CONCLUSION: The long-term results of CO(2) laser treatment of angiofibromas are unpredictable. The marked improvement obtained at 6 months is sustained in only a minority of cases at 24 months. Despite this, patient satisfaction appears relatively high. Initial clinical improvement may be the result of a combination of destruction of angiofibromas and their sequestration under postoperative fibrosis. The benefits of therapy should be weighed against both early morbidity and the risks of long-term complications such as scarring and hypopigmentation.
Adult↗
Polylactide-poly(ethylene glycol) micellar-like particles as potential drug carriers: production, colloidal properties and biological performance.
The micellar-like particle systems produced from poly-D,L-lactide-poly(ethylene glycol) (PLA-PEG) copolymers have been assessed using a range of physicochemical characterisation methods, followed by in vivo studies of their biodistribution after intravenous administration to the rat. The size of the PEG chain was kept constant at 5 or 2 kDa, while the PLA size increased within a series from 2 to 25 kDa. The results obtained reveal, that in an aqueous medium the copolymers assembled into micellar-like structures, with the PLA segments forming the core and the PEG segments the surrounding corona. The size of the PLA segments dominated the process of assembly of the molecules and the characteristics of the resultant micellar-like particles. The PLA-PEG micellar particles were found to be less dynamic than those obtained from conventional surfactants. Particles formed from the lower molecular weight PLA polymers allowed a level of chain mobility while the cores of the micellar particles formed from higher molecular weight PLA appeared to be solid-like in nature. The size of the micellar particles was dependent on the copolymer molecular weight and the z-average diameter increased from 25 to 76 nm as the molecular weight of the PLA moiety increased. This provides an ability to control the particle size by adjusting the molecular weight of the PLA moiety. Following intravenous administration to the rat model, micellar-like particles smaller than approximately 70 nm accumulated in the liver, despite the fact that the PEG corona provided an effective steric stabilization effect. Micellar-like particles with a diameter of more than approximately 70 nm exhibited prolonged systemic circulation and reduced liver uptake, although the steric stabilisation of these particles was shown to be less effective. These findings agree with recent observations from other research groups; that indicate a possibility that very small particulates can pass through the sinusoidal fenestrations in the liver and gain access to the parenchymal cells of the liver.
Animals↗
Lasers for the dermatologist.
This article reviews the current uses of lasers in dermatological practice. It outlines safety issues and legislation and attempts to summarize the relevant physics and light interactions. The article is divided into sections pertaining to selective photothermolysis of structures containing the major skin chromophores: haemoglobin, melanin and water. The lasers used and conditions treated are discussed with reference to a literature review.
Humans↗