Evaluation of 532-nm KTP laser treatment efficacy on acne vulgaris with once and twice weekly applications.

BACKGROUND: Light-based therapies and lasers have been proposed for the treatment of acne vulgaris but the efficacy and application periods of 532-nm KTP laser treatment are not clear. OBJECTIVE: To evaluate the efficacy and safety of 532-nm KTP laser and compare the effects of once and twice weekly applications in the treatment of mild to moderate acne vulgaris. METHODS: Totally 38 patients were treated once weekly and twice weekly in group I and in group II respectively. One half of the face of each patient was treated with 532-nm KTP and the other half was remained as untreated. Patients were evaluated at the beginning, one and four weeks after the last treatment session with Michaëlsson acne severity grading score (MASS). RESULTS: Statistically significant improvement was found at second control (p = 0.005) in group I, and at the first (p = 0.004), and second (p < 0.001) controls in group II for treated sides. For both groups, changes of MASS were insignificant for untreated sites. Improvement of MASS of treated sides was not statistically significant between two treatment groups for both controls. CONCLUSION: 532-nm KTP laser treatment may be an alternative method in selected acne vulgaris patients. No significant difference was noted between once and twice weekly applications.

Treatment of melasma with a depigmentation cream determined with colorimetry.

BACKGROUND: Melasma is a pigmentary disorder often recalcitrant to treatment. Few studies have objectively evaluated the efficacy of treatment colorimetrically. AIM: To evaluate the safety and efficacy of a depigmentation cream, including mainly glycolic acid and Rumex occidentalis. METHOD: Twenty-seven patients applied the cream twice daily for the first 3 months and twice weekly for the following 3 months. L*, C* and h* values of the target lesions and the perilesional area were analyzed at baseline, 12 and 24 weeks colorimetrically. The physician and patient evaluated the clinical response rate. These results were compared statistically between the lesional and perilesional area. RESULTS: There was a significant difference between 0-12, 0-24 (L*, C* and h* values) and 12-24 weeks (L* value) (p <0.001). For C* and h* values, the difference was not significant between 12 and 24 weeks (p = 0.464 and 0.151, respectively). Statistical significance was detected only between 3 and 6 months for C* value (p < 0.05) for the lesional and the perilesional areas. Clinical response rate was significant (p < 0.05). CONCLUSION: Our depigmentation cream is a moderate effective agent, well tolerated and can be considered as an alternative treatment of melasma. Twice-daily application may enhance the efficacy of treatment instead of twice-weekly application in the maintenance period.

Clinical comparison of potassium-titanyl-phosphate (KTP) versus neodymium:YAG (Nd:YAG) laser treatment for lower extremity telangiectases.

BACKGROUND: The Nd:YAG laser has been considered the gold standard of treatment for leg veins, but pain and side effects have fueled physicians to use treatment alternatives. OBJECTIVE: To compare the clinical efficacy of the long-pulsed 1064-nm Nd:YAG laser with KTP laser irradiation in the treatment of leg telangiectasia. METHODS: A series of 16 patients with size-matched superficial telangiectases of the lower extremities were randomly assigned to receive three consecutive monthly treatments with the long-pulsed 1064-nm Nd:YAG on one leg and 532-nm KTP laser irradiation on the other. RESULTS: For the 16 patients who completed the study, 64 leg vein sites were treated. Average clinical improvement scores were 1.94 and 1.25 for the KTP laser-treated leg and 3.38 and 3.50 for the Nd:YAG laser-treated leg with thin (≤ 1 mm) and large (1-3 mm) vessels, respectively. After the third treatment session, average improvement scores of 2.44, 1.31 and 3.75, 3.23 were given for the KTP and Nd:YAG laser-treated sides, respectively. CONCLUSION: Both the 1064-nm Nd:YAG and KTP lasers are effective in the treatment of lower extremity telangiectases. However, the KTP laser has very low efficacy with vessels larger than 1 mm and should not be elected when treating such vessels.