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العنوان
The Use of Q-Switched Nd: YAG Laser In Dermatology /
المؤلف
Saad, Yousra Raouf.
هيئة الاعداد
باحث / معتز بالله مصطفى الدمياطى
مشرف / وائل حسام الدين عبدالرازق
مشرف / غادة على ناصف
الموضوع
Skin - Laser surgery. Skin - Diseases - Treatment. Skin Diseases - therapy. Cosmetic Techniques. Laser Therapy - methods.
تاريخ النشر
2017.
عدد الصفحات
221 P. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
الطب (متفرقات)
تاريخ الإجازة
1/1/2017
مكان الإجازة
جامعة المنيا - كلية الطب - الأمراض الجلدية والتناسلية وامراض الذكورة
الفهرس
Only 14 pages are availabe for public view

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Abstract

Laser therapy no doubt has revolutionized and widened the dimension of treatments in dermatological conditions. During the past two decades, greater understanding of the complex laser-tissue interaction coupled with extensive advances in laser technology have refined cutaneous laser surgery to the point that it is considered a first line of treatment for many congenital and acquired skin conditions.
Since development of Q-switched lasers, they became the prime tool in treatment of benign pigmented lesions and different colors of tattoo. With four different wavelengths, they are able to treat different lesions at different locations, depths and colors of the skin. The main QS lasers used to treat hyperpigmentation are QS 532 and 1064 nm Nd:YAG lasers, the 694 nm ruby laser and the 755 nm alexandrite laser. These wavelengths are well absorbed by melanin pigments and less readily absorbed by hemoglobin, which is the other major chromophore in the skin.
The present work has been performed to study the clinical and histopathological efficacy of QS Nd: YAG laser in the treatment of some pigmentary disorders, tattoo removal and facial rejuvenation.
The present study has been conducted on 44 cases from the attendants of the outpatient clinic of the Dermatology, STD’s & Andrology department at Minia University Hospital during the period from November 2013 to November 2015. All the cases were treated with the QS Nd: YAG laser. Males represented 14 cases (31.8%) and females represented 30 cases (68.2%). Age of the patients ranged from 7 to 67 years with a mean and standard deviation (SD) of 27.93 ± 13.18 years.
The patients (44 cases) were classified into the following groups: group I: Benign pigmented lesions (24 cases), which is further divided into 3 subgroups: Nevus of Ota group consisting of 12 patients, Becker’s nevus, 6 patients, and café-au-lait macules group, 6 patients, group II: Tattoo removal, consisting of 12 patients, group III: Facial rejuvenation, consisting of 8 patients.
All the patients were subjected to full history taking, clinical examination, and photo-documentation. Skin biopsies were taken before treatment and after 6 sessions.
In nevus of Ota group, more than 74% of patients showed excellent to good response. Histopathological and histometric evaluation showed evident decrease in the number of dermal melanocytes.
In Becker’s nevus group, excellent to good response was observed in only 33.3% of the patients. Skin biopsies showed decrease in the melanin content of basal keratinocytes in improved cases.
In the CALM group, 16.7% of the patients had excellent response, while 33.3% had good to fair improvement. Skin biopsies also showed decreased hyperpigmentation of the basal keratinocytes in improved cases.
The use of QS lasers has revolutionized the field of tattoo removal by selectively targeting and clearing tattoo pigment with a minimal risk of textural changes and scarring.
In the tattoo group, more than 66% of the patients showed excellent response, while the rest showed good response. Skin biopsies and histometric evaluation showed almost complete disappearance or significant decrease of the tattoo pigment.
Cutaneous aging is a complex biological phenomenon affecting different constituents of skin. There are two independent, clinically and biologically distinct, processes affecting the skin simultaneously. The first is intrinsic aging, “the biologic clock” that affects the skin in the same manner as it affects the internal organs, i.e. by slow, irreversible tissue degeneration. The second is extrinsic aging, “photoaging”, which is the result of exposure to out-door elements, primarily UV irradiation.
In the rejuvenation group, 12.5% of patients showed excellent response, 12.5% showed good response, and the rest had fair to poor response. Skin biopsies revealed a mildly thickened upper papillary collagen zone with an improvement of collagen fibrils as they appear regular and smooth, especially in improved cases.
In conclusion, Q-switched laser systems are still considered the gold standard for the removal of tattoos and the treatment of benign pigmented lesions. QS laser treatment guarantees high clinical efficacy, rapid healing time and minimal post-operative side effects.