This clinical observational study investigates the dose-response relationship between laser energy intensity and skin damage/repair by applying different parameter sets of fractional ablative (CO2) and non-ablative (M22) lasers to the inner forearms of approximately 20 healthy Chinese female volunteers (aged 18-60, Fitzpatrick skin types III-V) in a single-center, self-controlled design. Each participant receives both laser types on contralateral arms, with four distinct energy/density combinations per laser applied to separate test areas, and the dynamic skin responses are evaluated at baseline, immediately post-treatment, and at 30 minutes, 1, 2, 3, 4 hours, 7 days, and 10 days thereafter through clinical assessments (edema, erythema, etc.), standardized photography, high-frequency ultrasound (Dermascan), and objective instrumental measurements of skin color (Chromameter CM26dG), melanin/hemoglobin (Mexameter MX18), and barrier function (TEWL via Vapometer). The collected data will be analyzed using descriptive and comparative statistical methods to characterize the acute injury and recovery profiles, aiming to establish a foundational model for future post-procedure cosmetic intervention research.
Female Chinese study participants aged 18 to 60 years (inclusive).
Fitzpatrick skin phototypes III, IV, or V.
Willing to receive non-ablative fractional laser (M22) and ablative fractional laser (CO2) irradiation on the test sites during the study.
No primary or secondary lesions (such as scars, ulcers, vesicles, tattoos) on the test sites.
Study participants with skin diseases or skin allergies in the test area.
Presence of moderate to severe inflammatory skin diseases (e.g., active eczema, acute photosensitive dermatitis, etc.) on the test sites within the past 4 weeks, or those who require treatment with oral or topical corticosteroids or immunosuppressants for skin conditions.
On the day of the visit, the investigator judges the presence of significant diffuse erythema, desquamation, or exudation in the test area that may significantly affect skin color measurement.
The investigator assesses that the participant is currently suffering from a stable or progressively worsening disease.
Approximately 20 healthy Chinese female volunteers, aged 18-60 years with Fitzpatrick skin phototypes III, IV, or V. This population will serve as participants in a self-controlled, observational study to model laser-induced skin injury. Each participant will receive both ablative (CO2) and non-ablative (M22) fractional laser exposures with varying parameters on their inner forearms to observe the dynamic physiological response and recovery process.
Other
Prospective
Ablative Fractional Carbon Dioxide Laser
Procedure/SurgeryThis intervention involves the application of ablative fractional laser using a carbon dioxide (CO₂) laser system. Four distinct parameter combinations will be used on four separate test areas (each 1.5cm x 1.5cm) on the participant's inner forearm. The varied parameters include different settings for energy (mJ), spot spacing, and density. The procedure creates microscopic columns of thermal injury in the skin to study the acute tissue response and subsequent healing process. The specific device and parameters are part of the study protocol and are not being evaluated for a new indication.
Non-ablative Fractional Laser (1565 nm)
Procedure/SurgeryThis intervention involves the application of non-ablative fractional laser using a 1565 nm wavelength laser system (e.g., M22 ResurFX). Four distinct parameter combinations will be used on four separate test areas (each 1.5cm x 1.5cm) on the participant's inner forearm. The varied parameters include different settings for energy (mJ) and density. The procedure delivers focused photothermal energy to the dermis without disrupting the epidermis, aiming to study the sub-surface tissue response and recovery dynamics. The specific device and parameters are part of the study protocol and are not being evaluated for a new indication.
Change in Composite Clinical Skin Damage Score as Assessed by Clinician
Change in Skin Color Parameters (L, a, b*, ITA°) measured by Chromameter CM26dG
Change in Melanin and Hemoglobin Index measured by Mexameter MX18
Change in Transepidermal Water Loss (TEWL) measured by Vapometer
