Comparison Of A Er:YAG 2940nm Ablative Fractional Laser Device And A Erbium-doped Glass1550nm Non-ablative Fractional Laser For The Treatments Of Acne Scar

Efficacy and safety of Er:YAG 2940nm ablative fractional laser for the treatment of atrophic acne scar[Background]Scar tissue is a natural product in the process of wound healing, it can be sorted in various species. Among teenager, the most vulnerable scar is acne-post scar. The types of acne scars are divided into a lot of species, the most common type is atrophic acne scars. Acne is a kind of pilosebaceous unit chronic inflammatory skin disease which commonly attacks the adolescents in dermatological clinic, also, female suffered less in amount but earlier in age than male. Although it is self-limited, acne, such as formation of acne scar can be sustainable for life. It not only brings patients with facial damage of capacitive change, but also keeps serious impact on social and psychological confidence. According to the shape of acne scar it can be divided into two kinds:one kind of atrophic scar, the other is a hyperplastic scar including keloid. Atrophic scar can be classified as icepick, rolling and carriages boxcar. The appearance of acne atrophic scar is vertical fiber bundle to dent of skin, which is caused by the decrease of collagen deposition in the healing process. Acne scar treatment methods are various. According to the differences of acne scarring, there are different treatment methods, so the curative effect is also different. There are in drill resection, subcutaneous cutting, grinding, chemical group, stripped the filling technique and laser micro needle which is developed fast recently.Laser of the treatment of atrophic acne scars has a good curative effect, high safety of unique advantages. Fractional laser makes tissue water for the target, generate array sample arrangement of small beam applied to the skin. After skin tissue water absorbs laser energy, it will produce multiple microscopic treatment zones, cause a series of biochemical reactions of skin. Dermal collagen contract immediately, collagen type I denature, and become the synthesis of new collagen matrix, start new collagen and rearrangement, melanin is shed of dermal skin away, and to tight skin, get skin rejuvenation and improve the light aging. Fractional laser combined with ablative laser’s aggressive treatment of rapid and significant effect, but also has no-ablative laser’s side effects and the recovery time is short. Fractional laser has been widely applied in clinic, can be used to treat acne scars including atrophic scar, hyperplastic scar, photoaging and so on. According to whether to produce gasification, fractional laser can be divided into ablative and non-ablative laser. The key to the treatment of atrophic acne scars is to increase the content of dermal collagen type I and grind the scar edge, making the skin looks more smooth. The efficacy of treatment of atrophic acne scar of 2940nm is good, but some literatures report that the efficacy is different according to the different types of acne scar. The experiment is to observe the efficacy and safety of 2940nm laser of treatment of atrophic acne scar.CK skin property can detect the skin barrier function with transdermal water loss, skin water content, facial oils, skin erythema and melanin index.[Objective]To observe the efficacy and safety of 2940nm in atrophic acne scar treatments.[Methods]35 patients consult and diagnosed with atrophic acne scars in March to December of 2014 received three split-face monthly treatments. Among the 35 patients, there are 10 men and 25 women; the age ranges from 20 to 32, the average age is 26.7; the course of disease ranges from 1 to 2 years, the average course is 1.1 years; the lesion area is 20～55 cm2, there are ice-pick, rolling and boxcar types acne scars in patients’ faces. All the skin lesions were stable in patients’faces, all the lesions were stable at more than six months. The patients Fitzpatrick type is Ⅲ-Ⅳ. All the patients were signed informed consent.25 patients presented with atrophic acne scars underwent 2940nm ablative fractional laser system, the laser parameter is: mode Long, energy 1500-1800mJ, spot diameter 7mmx7mm, repeat 3 times, roller laser head, mode Middle, enery 400-500mJ. The treatment was performed total 3 times, at 4-week interal. Make assessment of efficacy by images and ECCA weighted score, and safety by CK skin property.[Results]All patients were improved,54.2% efficient. Among 35 patients,19 patients got improved significantly,14 patients got moderate improvement,2 patients got minimum improvement. After 3 treatments, the ECCA weighted score decreased obviously. There is significant difference between before and after treatments, and the ECCA weighted score of rolling scars and shallow boxcar decreased more obviously than other types. One week after treatments, the transdermal water and the facial oils increased and the water content decreased compared with before. One month after treatment, the transdermal water, the water content and the facial oils has no significant differences compared with before treatment.[Conclusions]1.2940nm Er:YAG laser has a clear and definite effect in treatment of atrophic acne scars.2.2940nm Er:YAG laser has a obvious effect in rolling scars and shallow boxcar scars.3.2940nm Er:YAG laser repair atrophic acne scars is safe.Comparison of a Er:YAG 2940nm ablative fractional laser device and a erbium-doped glass 1550nm non-ablative fractional laser for the treatment of atrophic acne scar:a split-face clinical[Background]According to whether to produce gasification, fractional laser can be divided into ablative and non-ablative laser. Ablative fractional laser beams can make skin generated aperture in the true sense; non-ablative fractional laser beams only cause a columnar thermal denaturation area, the skin has no real aperture. The difference between the two lasers is that non-ablative fractional laser is absorbed by water mild and will not damage skin stratum, epidermis tissue get coagulation but not gasification, the thermal damage are includes the skin tissue below stratum and dermal tissue of different depth, no-ablative fractional laser is mild relatively and recover quickly. But the ablative fractional laser is absorbed by water level, the thermal damage area including dermal tissue of different depth, ablative fractional laser’s function is strong, and need a long time recovery. There are reports about ablative fractional laser and non-ablative fractional laser both for the treatment of atrophic acne scars at home and abroad, the principles of two lasers are different. The key to the treatment of atrophic acne scars is to increase the content of dermal collagen type Ⅰ and grind the scar edge, making the skin looks more smooth.VISIA skin image analyzer is a kind of multiple spectral imaging technology, which carries a 12000000 megapixel camera, generating image from three different angles by white light, ultraviolet light and cross section polarized light, to provide accurate, quantitative analysis of the basis from different aspects on the skin. It is reported that VISIA skin image analyzer can be used as a quantitative measurement of the laser and intense pulsed light effect all over the world, and being applied in effect and quantitative evaluation in a variety of skin diseases such as chloasma, acne scars and wrinkles. CK skin property can detect the skin barrier function with transdermal water loss, skin water content, facial oils, skin erythema and melanin index. The skin tester is used widely to test the skin barrier function both domestic and overseas.[Objective]To compare with the efficacy and safety of the Er:YAG 2940nm ablative fractional laser and the erbium-doped glass1550nm non-ablative fractional laser in atrophic acne scar treatment. We chose ten patients with atrophic acne scars who had received three split-face monthly treatments. One side of face with Er:YAG 2940nm ablative fractional laser, and the other with erbium-doped glass1550nm non-ablative fractional laser. We measured the effect using photos and VISIA complexion analysis system at before and 1 month after the every treatment. Using CK skin property before treatment, 1week and 1 month after the every treatment. Then make the skin collagen Masson staining, collagen type Ⅰ immunohistochemical semi-quantitative determination before and after the 3 treatments. At last, compare and discuss the efficacy and safety of two laser devices by the naked perceptual eyes, skin objective index and pathological immunohistochemical semi-quantitative three aspects for the better use in the clinical treatment.[Methods]Ten patients consult and diagnosed with atrophic acne scars in March to December of 2014 received three split-face monthly treatments. Among the ten patients, there are four men and six women; the age ranges from 21 to 25, the average age is 23.6; the course of disease ranges from 1 to 5 years, the average course is 3.1 years; the lesion area is 20～50 cm2, the atrophic acne scar type is given priority to ice-pick type, the scar concave depth in 0.2-0.5mm. All the skin lesions were stable in the faces, all the lesions were stable at more than six months. The patients Fitzpatrick type is Ⅲ～Ⅳ. All the patients were signed informed consent. The patients received the Er:YAG 2940nm ablative fractional laser and the erbium-doped glass1550nm non-ablative fractional laser randomly in two split-face. Patients received three split-face monthly treatments. The Er:YAG 2940nm ablative fractional laser parameter is:energy 31mJ/mb (1500 mJ/pulse), mode Long, spot diameter 7mmx7mm, repeat 3 time; the erbium-doped glass1550nm non-ablative fractional laser parameter is:energy 45mJ/mb, energy density 160/cm2, repeat 1 time(both are the low energy of recommended energy). Taking photos and use VISI A complexion analysis system at before treatment and 1 month after the every treatment for the skin detection of march pores, texture, purple pores and so on; use CK skin property at before, 1week and 1month after the every treatment for the skin detection of transdermal water loss, water content, facial oils, melanin and so on. before the first treatment using trephine pitting 1 piece acne scar skin biopsies, and after three treatments using trephine 2 pieces acne scar skins which treated effectively. Make skin collagen Masson staining and immuneohistoch-emical with collagen type Ⅰ. Observe the skin collagen and the content changes of collagen before and after treatment, the left and right controls. All the experimental data use SPSS statistical software to analyze.[Results]All cases were improved,30% efficient. Among ten patients, three patients got improved significantly, six patients got moderate improvement, one patient got minimum improvement. There are six patients think the side treated by 1550nm laser got better curative effect and better satisfaction; there are two patients think the side treated by 2940nm laser got better curative effect and better satisfaction; and the rest two patients regard the 1550nm laser’s curative effect and satisfaction as same as 2940nm laser’s, there is no significant difference. By the way, all the patients think skin color is brightened and the skin quality is improved.Every time after treatment compared with before treatment, the second time and the third time after treatment compared with the first time treatment, the third time after treatment compared with the second time after treatment, march pores and purple pores were both reduced; and three times after treatment compared with before treatment, march pores and purple pores were reduced significantly(P<0.05). The second time and the third time after treatment compared with before treatment, The second time and the third time after treatment compared with the first time after treatment, brown spots reduced(P<0.05). Compared with before treatment, the wrinkle, texture, pigment spot, red area, UV pigment did not changed significantly (P>0.05). There is no significant difference between 1550nm laser side and 2940nm laser side of march pores absolute value before treatment. After the first, second, third time treatment, the march pores absolute value of 1550nm laser side is more significant than 2940nm laser side(P<0.05) compared with before; there is no significant differences in purple pores and brown spots absolute value between 1550nm laser and 2940nm laser(P>0.05).The collagen under the microscope before the treatment arranges in disorder, and is loose, and the quantity of collagen reduces. The collagen under the microscope after the treatment is thick, and arranges densely, the quantity of collagen increases. The collagen arrangement of side treated by 1550nm laser is denser than the side which is treated by 2940nm laser. The collagen type Ⅰ under the microscope before the treatment is less than after the treatment. And the quantity of collagen type Ⅰ of side treated by 1550nm laser is more than the side which is treated by 2940nm laser.[Conclusions]1. The Er:YAG 2940nm ablative fractional laser and the erbium-doped glass1550nm non-ablative fractional laser of the treatment of atrophic acne scars have definite curative effect, the patients’ satisfaction is high.2. When using the middle and low of recommended energy for treat the ice-pick atrophic acne scar, the erbium-doped glass1550nm non-ablative fractional laser is more effective than Er:YAG 2940nm ablative fractional laser.3. The immediate postoperative edema and pain of 1550nm laser side is more serious than 2940nm laser side. The immediate erythema, bleeding of 2940nm laser side is more serious than 1550nm laser side; and scar taking off is longer than 1550nm laser side and the transdermal water is more serious than 1550nm laser, the damage of skin barrier of 2940nm is more serious.4. Both two lasers can increase the content of collagen type Ⅰ, the addition of dermal collagen type Ⅰ content of 150nm laser side is more than 2940nm laser side.