Determination of optimal parameters for laser for nonablative remodeling with a 1.54 microm Er:glass laser: a dose-response study.

BACKGROUND: Nonablative subsurface heating is a challenge for medical laser companies. Among the different lasers proposed today, the erbium-glass (Er:glass) laser combined with contact cooling could be an alternative for nonablative remodeling. OBJECTIVE: To investigate the risk of side effects according to the quality of cooling and number of pulses. METHODS: A clinical evaluation was performed on 10 patients using an Er:glass laser (1.54 microm) with contact sapphire cooling handpiece (+5 degrees C). Periorbital and perioral areas were treated with a number of pulses increasing gradually from three to eight for a total energy of 24-64 J/cm2. The presence or absence of swelling, crust, blister, and erythema were graded at 7 days. At 3 months postoperatively, hypopigmentation, hyperpigmentation, textural changes, and scars were evaluated clinically. RESULTS: Periorbital and perioral areas respond differently to the number of pulses defining a "safe" clinical threshold. The periorbital site is very sensitive to dermal heating and efficacy of contact cooling; the anatomic features of this body location may explain these differences. CONCLUSION: Selective dermal heating can be achieved with an Er:glass laser coupled with a contact cooling handpiece. The quality of the contact cooling and the number of pulses appear to be important parameters for safety and reproducible clinical results.