An examination of the excimer laser and its applications

Vanessa Ngan, Staff Writer,

An examination of the excimer laser and its applications

The authors report no relevant conflicts of interest. To review the current therapy for granuloma annulare and report a case of refractory generalized granuloma annulare successfully treated with excimer laser.

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A discussion about the characteristics of excimer laser and the mechanism of its effectiveness is presented. Patient case report and literature review. A year-old woman suffering from generalized granuloma annulare for more than 40 years.

Change in clinical appearance of lesions. Use of excimer laser therapy resulted in prompt and complete resolution in treated areas with no residual skin changes or side effects. Excimer laser therapy is a powerful treatment modality with minimal side effects for patients with granuloma annulare.

Further study is necessary to elucidate optimal dosing, long-term efficacy, and safety profile. J Clin Aesthet Dermatol. Granuloma annulare GA is a relatively common disorder with a female predominance that usually presents as 1 to 5cm skin-colored or erythematous annular plaques with peripheral papules.

While the localized form most frequently affects the dorsal surfaces of the extremities, GA may also have a generalized distribution characterized by more than 10 sites of involvement, frequently including the trunk, neck, scalp, and occasionally face. The localized form has the highest incidence in patients under 30 years old and tends to have spontaneous resolution, with approximately one-half of lesions resolving within two years after diagnosis.

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Generalized GA exhibits more tenacious behavior and can occasionally be present for more than 10 years without resolution. This idiopathic reaction is believed to be a type IV hypersensitivity response to an unidentified antigen.

Localized GA has been successfully treated with topical therapy, including steroids under occlusion, intralesional steroid injections, and cryotherapy. Reports of successful treatment with topical tacrolimus as well as a combination of rifampin, ofloxacin, and minocycline have also been observed.

Treatment duration is dependent on extent of disease and response to treatment. Long-term use leads to actinic damage localized to treatment areas and an increased risk of cutaneous malignancy.

Case reports have shown inconsistent efficacy, with either primary treatment failure or recurrence of lesions after discontinuation of therapy; the majority of cases, however, respond to the drug.

These requirements as well as the potential systemic side effects, including hyperlipidemia, hyperglycemia, hepatitis, hematologic dyscrasias, and mental status changes, decrease patient compliance with therapy.

An examination of the excimer laser and its applications

Several reports demonstrated that dapsone had clinical merit in resolving generalized GA, but treatment failures resulted from drug ineffectiveness and intolerable side effects ranging from headaches, nausea, and hepatitis to agranulocytosis and aplastic anemia.

After treatment is initiated, complete blood counts CBCs are drawn weekly for the first month of therapy and then monthly for six months. Baseline liver function should be evaluated and values rechecked every three months of therapy.

An examination of the excimer laser and its applications

Recently, Inui et al[13] reported a patient with GA unresponsive to topical steroids and tacrolimus treated with narrowband ultraviolet B NBUVB resulting in resolution in 24 treatments with absence of recurrence.

Over the past 40 years, she has had lesions present on her trunk and extremities with gradual involvement of a larger surface area. Her past medical history was negative for diabetes, hypothyroidism, and diagnosed malignancy, and she denied any family history of autoimmune disease or dermatological conditions.

On exam, she had numerous serpiginous plaques and erythematous papules on her chest, abdomen, back, and extremities, sparing the face Figure 1. At higher magnification, there was an interstitial proliferation of histiocytes and multinucleated cells palisading around zones of altered collagen and mucin, with a perivascular lymphocytic infiltrate, suggesting granuloma annulare Figure 3.

After discussion of her treatment options, the patient consented to a trial of excimer laser therapy on the dorsum of her hands. After 15 treatment sessions, there was complete resolution with no residual scarring Figure 4.

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The patient tolerated the procedure and reported no side effects. At her six-month follow up, she had no recurrence of GA in treated areas. Discussion The effectiveness of light therapy in the treatment of skin disorders marked by aberrant immune response relates to the antiproliferative effects of UV light on cutaneous lymphocytes via formation of pyrimidine dimers with induction of lymphocyte apoptosis.

This mechanism may explain the observed effectiveness of excimer laser therapy in both resolving and suppressing further GA lesions. The excimer laser system is a source of nm wavelength light, which has shown efficacy in treating psoriasis, vitiligo, atopic dermatitis, and other inflammatory dermatoses.

It delivers a precise band of light, eliminating the unnecessary treatment of healthy perilesional skin and hyperpigmentation that may occur. This delivery system allows for higher fluence settings and consequent shorter treatment times, with studies reporting a lower cumulative dose necessary to achieve patient satisfaction.

Conclusion A case of generalized GA treated with the excimer laser resulted in resolution of lesions that had been refractory to other therapies.The COMPex excimer laser provides multi-hundred millijoules output and unmatched pulse-to-pulse stability.

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It is ideal for demanding applications such as solid sampling (LA-ICPMS), material research (PLD), and precise material processing. · The excimer laser also excels others in its ability to ‘mask-project’ patterns, using stencil or metal-on quartz masks on to a sample with a minimal Heat Affected Zone (HAZ).

The minimal HAZ is due to the short pulse duration/interaction time between the laser beam and the timberdesignmag.com://timberdesignmag.com The raw laser beam produces energy density of > mJ/cm 2 which is comparable to the performance of standard (large) excimer lasers.

Its very short pulse length (3 ns), permits extremely high peak power density (30 MW/cm 2).timberdesignmag.com Analysis and Fabrication of Microfluidic Systems by Excimer Laser Micromachining and Its Applications for Microfluidic and Bio-Medical Devices.

Show full item record. Title: Analysis and Fabrication of Microfluidic Systems by Excimer Laser Micromachining and Its Applications for Microfluidic and Bio-Medical timberdesignmag.com://timberdesignmag.com  · The excimer laser is FDA approved for PRK, but not for Lasik, which is a combination of ALK and PRK.

The Lasik procedure comes under the definition of the practice of medicine (also called scope of practice), so the FDA does not necessarily need to approve the use of the excimer laser timberdesignmag.com  · Excimer Laser Micromachining and its Applications involved are large, due to the high gain of the lasing medium, and the output is at ultraviolet timberdesignmag.com://timberdesignmag.com

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