Aim: A clinically useful treatment laser must generate stable and precise energy of low diffusivity. This study assessed the photothermal response of a Q-switched ruby laser (QSRL) in the treatment of oculodermal mela...Aim: A clinically useful treatment laser must generate stable and precise energy of low diffusivity. This study assessed the photothermal response of a Q-switched ruby laser (QSRL) in the treatment of oculodermal melanosis (Nevus of Ota).Methods: A two-year retrospective review of 40 patients with oculodermal melanosis treated with a QSRL (λ = 694 nm, pulse duration = 25 ns, 3 mm spot size, energy density 6-10 J/cm2) was performed. Demographics included an age range of 18-54 years (mean 28) and a gender distribution of 25 females and 15 males. The values recorded from real-time infrared thermal imaging of the lasered skin were inserted into standard thermal wave equations. This permitted analysis of the resultant temperature distributions related to the energy change.Results: Skin temperature was unchanged during the initial heating stage. This was followed by a very rapid temperature rise. A thermal burn injury manifested by dermal-epidermal disruption, resulted when the energy density of the QSRL exceeded 8 J/cm2 (> 44℃).Conclusion: The use of infrared thermal imaging with a standard thermal wave equation allows prediction of skin temperature distribution when QSRL is used for the treatment of oculodermal melanosis. With the use of appropriate settings, complications may be minimized.展开更多
文摘Aim: A clinically useful treatment laser must generate stable and precise energy of low diffusivity. This study assessed the photothermal response of a Q-switched ruby laser (QSRL) in the treatment of oculodermal melanosis (Nevus of Ota).Methods: A two-year retrospective review of 40 patients with oculodermal melanosis treated with a QSRL (λ = 694 nm, pulse duration = 25 ns, 3 mm spot size, energy density 6-10 J/cm2) was performed. Demographics included an age range of 18-54 years (mean 28) and a gender distribution of 25 females and 15 males. The values recorded from real-time infrared thermal imaging of the lasered skin were inserted into standard thermal wave equations. This permitted analysis of the resultant temperature distributions related to the energy change.Results: Skin temperature was unchanged during the initial heating stage. This was followed by a very rapid temperature rise. A thermal burn injury manifested by dermal-epidermal disruption, resulted when the energy density of the QSRL exceeded 8 J/cm2 (> 44℃).Conclusion: The use of infrared thermal imaging with a standard thermal wave equation allows prediction of skin temperature distribution when QSRL is used for the treatment of oculodermal melanosis. With the use of appropriate settings, complications may be minimized.
