Nonlaser induced selective photothermolysis can also be used for hair removal and has been utilized with a filtered flashlamp intense pulsed light (IPL) sources. The IPL technology emits a broad spectrum of light that is filtered to allow release of varying emitted wavelengths of light. Cutoff fillers are utilized to select either shorter or longer wavelengths. A higher cutoff filter blocks many shorter wavelengths and thus is generally used when treating darker skin types.
So far, only a few investigators have evaluated this modality for hair removal (Table 5.1). Gold et al. published the first significant series of patients treated with IPL [32]. They evaluated hair removal efficacy in 31 subjects, the majority between 30 and 50 years of age. Although a variety of anatomic sites were treated, the most common areas were the neck (27%), lip (22%), and chin (19%). All sites were treated at the same time and evaluated 2, 4, 8, and 12 weeks after treatment. Treatment parameters varied according to the pigmentation of the skin and treated hair. Four cutoff filters were used: 590, 615, 645, and 695 nm. Fluences ranged between 34-55 J/cm2 and were delivered in sequences of between 2-5 pulses, each pulse varying between of 1.5-3.5 msec in length. The authors reported that after a single treatment, approximately 60% hair removal was noted at 12 weeks. They concluded that IPL was a safe and effective method for long-term hair reduction.
Table 5.1 Summary of Studies Using IPL Sources for Hair Removal
IPL = intense pulsed light. |
Weiss et al. evaluated the efficacy of IPL hair removal in 48 subjects with Fitzpatrick skin types I-V [33]. All patients were treated two times, with a one-month interval between the treatments. Anatomic sites treated included both facial regions and nonfacial regions. At week eight, a 42% hair reduction was noted. At six months, hair reduction was found to be 33%. Sadick et al. also performed hair removal with an IPL device and had successful results [34]. They impressively reported an 83% hair reduction after a mean of 3.9 patients in 14 patients, who were followed up between 12 and 26 months after their last treatment.
Lee et al. studied the photo-epilatory effects of two different wavelengths of the same IPL device in an Asian population [35]. They treated 28 patients with a 600-950 nm filter and 27 patients with a 645-950 nm filter. Longer pulse widths were utilized in the 645950 nm groups. Four treatments were performed at intervals of 4-6 weeks. Eight weeks after the final treatment, the average clearance was 52.8% (600-950 nm filter) and 83.4% (645-950 nm filter). They concluded that removing 45 nm of the emitted spectra and applying a longer pulse width provided a safer and more effective treatment in this population.
Several groups have compared IPL to laser sources commonly used for hair reduction. Amin et al. compared IPL hair removal with two different sets of parameters to laser hair removal with an alexandrite and diode laser. Hair reduction efficacy was found to be identical with the IPL and both lasers [36]. Another group retrospectively compared the efficacy of long – and short-pulse alexandrite lasers with an intense light source for photo-epilation in 389 patients [37]. Overall, no statistically significant difference in efficacy was found between patients treated with the alexandrite laser and those who received IPL treatment. However, those treated with an alexandrite laser required 6-8 treatments, while those who received IPL treatment required 8-9 treatments. Finally, Toosi et al. also compared IPL hair removal to the alexandrite and diode laser in 232 patients. Six months after the last session, they found no statistical difference between light sources [38].