Intense Pulsed Light (IPL) for the treatment of vascular and pigmented lesions

IPL devices emit a wide range of wavelengths that can be absorbed by different chromophores in the skin. Selective destruction of a specific chromophore with minimal side effects is controlled by wavelength, pulse duration, and fluence.


| INTRODUC TI ON
Intense pulsed light (IPL) is a flash lamp device that emits polychromatic, noncoherent light, typically in the range of 500-1200 nm.
2][3] For more precise tissue targeting, the selective photothermolysis approach is applied to achieve controlled destruction of a specific target while sparing adjacent tissue. 2,4The three key principles that govern this approach are wavelength, pulse duration, and fluence.The wavelength range determines which chromophores are targeted.By incorporating different cutoff filters, the wavelength range can be managed, with the selection of the appropriate filter typically based on the patient's skin type, current skin condition, and the location of the target chromophore in the skin.Pulse duration affects the distribution of heat during procedures.To prevent thermal damage from heat diffusion into adjacent tissues, the pulse duration must be shorter than the thermal relaxation time (TRT) of the target chromophore, which is the time required for the target to lose half of its peak temperature after irradiation. 1,2Delay times between sequential pulses can be used to accommodate epidermal TRT. 5 In addition, recent advances in technology have enabled IPL systems to deliver square pulses that have a few clinical benefits while minimizing side effects. 6The square pulse eliminates the initial energy peak and avoids energy attenuation at the end of the pulse.Square pulse IPL results in less discoloration under rational operation. 1nally, the fluence (J/cm2), which describes the amount of energy delivered per unit area, must ensure that sufficient thermal energy is delivered to the target tissue. 1,2Importantly, side effects tend to be more common at higher fluences and in darker-skinned individuals.Cooling devices keep the epidermis cool while delivering higher fluences, allowing the energy to penetrate deeper without excessive absorption at the surface. 5Wavelength, pulse duration, and fluence are all factors that allow IPL treatment to be specifically directed to a particular skin type or lesion type and guide the selection of the appropriate device. 2,3There are numerous IPL devices on the market today, each with a unique set of parameters, so the efficacy and safety profile may not be consistent between devices. 7e purpose of this study is to validate the safety and efficacy of a novel setting IPL device optimized to treat vascular and pigmented lesions in various areas of the skin.

| Study design
This was a retrospective study with a primary objective to evaluate the efficacy and safety of using an IPL applicator for the treatment of vascular and pigmented lesions.

| Patients
One hundred (100) healthy males and females with vascular and pigmented lesions on the face and body were treated with the IPL device.For the treatment of vascular lesions, 50 healthy subjects aged 18-61 years (mean age 34.5 ± 9.56 years) were included, of which 30 were female and 20 were male.Twenty-one subjects (42%) had Fitzpatrick skin type II and 29 subjects (58%) had Fitzpatrick skin type III (Figure 1).All patients were treated on the face.For the treatment of pigmented lesions, 50 healthy subjects aged 25-61 years (mean age 34.5 ± 7.4 years) were included.Forty-six subjects were female and four were male.Twenty subjects (40%) had Fitzpatrick skin type II, 25 subjects (50%) had Fitzpatrick skin type III, and five subjects (10%) had Fitzpatrick skin type IV.Fortysix subjects were treated on the face and four subjects were treated on the body.All patients were in good physical health with no major underlying medical conditions, and none had skin diseases or were taking medications that could affect skin condition.Patients were instructed to limit sun exposure and to use an approved sunscreen of SPF 50 or higher on the treatment area during the study and follow-up periods.The following criteria were used to exclude subjects from the study: previous treatment of the area to be treated at least 6 months prior to screening; skin type VI; pregnant, planning to become pregnant during the study, less than 3 months postpartum, or less than 6 weeks following breastfeeding; sun exposure or artificial tanning within 3-4 weeks prior to treatment.Any residual tan, sunburn, or artificial tanning products; active infection in the treatment area; chronic or cutaneous viral, fungal, or bacterial disease; tattoos in the areas to be treated.

| Treatment procedure
All patients received one to four treatments at 3-week intervals, with the number of treatments determined by the physician based on patient response, and a follow-up visit 3 months after the last session.Lesions were treated with an IPL cooled applicator (Dye-VL PRO, Alma Lasers Ltd., Caesarea, Israel) equipped with Advanced Fluorescence Technology (AFT).The 450-600 nm wavelength range generated by the device is optimal for hemoglobin absorption and is also highly utilized by melanin.The AFT converts unused UV light into the optimal spectrum and allows for a square pulse with fluence evenly distributed throughout the pulse, providing optimal energy in a short, continuous pulse duration.Treatment parameters were 3 cm 2 spot size and 1-3 s pulse duration at 5 J/cm 2 fluence.

| Efficacy evaluation
At the three-month follow-up visit, experienced physicians assessed the overall improvement in the appearance of the lesions

| Safety evaluation
The incidence and severity of adverse events were monitored throughout the treatment and follow-up period, and participants reported if they experienced pain during treatment.

| Statistical analysis
Statistical analysis was performed with Microsoft Excel.
Descriptive statistics were used to summarize patients' demographic characteristics.Means and standard deviations were calculated for continuous variables and percentages for categorical variables in each treatment group.A two-sample t-test assuming equal variance was performed using the Microsoft Excel Analysis Tool to investigate potential differences in treatment efficacy, as assessed by the GAIS score, between the vascular lesion group and the pigmented lesion group at a significance level α = 0.05.
In addition, the correlation between patient satisfaction and physician-reported GAIS scores was calculated for all 100 patients in both groups.

| RE SULTS
One hundred patients were included in this retrospective data collection study and completed all treatments and follow up visits.Fifty patients were treated for vascular lesions and fifty-for pigmented lesions.Patient demographics are shown in Table 1.
There was no statistically significant difference between the mean GAIS scores of the two groups.The p-value of the two-sample t-test was 0.49.In addition, there was a strong positive association between patient satisfaction scores and GAIS scores across the entire cohort of 100 patients, as indicated by a correlation coefficient of 0.8.

Examples of visual improvement of face lesions are presented in
Figures 3 and 4.

| Safety assessment
No pain issues were reported during the treatment sessions.During the study, one patient experienced a first-grade forearm burn that completely resolved within 8 weeks, and another patient experienced a first-grade leg burn that completely resolved within 10 weeks.Both incidents occurred when the device was used for body treatments and were primarily attributed to the use of the stack mode, where the applicator is stationary on the treatment area.No other adverse events were recorded.No incidence of edema, ecchymosis, vesiculation, dyspigmentation, or scarring was observed.

| DISCUSS ION
The results of this retrospective analysis suggest that a narrowband IPL device has an excellent safety and efficacy profile when used to treat pigmented and vascular lesions.When comparing efficacy as measured by GAIS scores between vascular and pigmented lesions, there was no statistically significant difference (p = 0.49) between the two groups.This implies that the response to therapy was comparable for both lesions and suggests that the treatment is effective for lesions of different etiologies, including both vascular and pigmentary origin.
The clinical effects of lasers and light-based devices are mediated by the absorption of photons in skin target chromophores, 8 leading to the selective destruction of the target in a process known as selective photothermolysis. 9Oxyhemoglobin is usually the target chromophore in the treatment of vascular lesions and has major absorption peaks at wavelengths of 410, 540, and 577 nm, whereas melanin, the target chromophore in pigmented lesions, absorbs the entire visible spectral range (400-750 nm). 10,11The most commonly used vascular lasers in current clinical practice are potassium titanyl phosphate (KTP, 532 nm), pulsed dye laser (PDL, 585-595 nm), alexandrite (755 nm), diode (800-810, 940 nm), and neodymium-doped yttrium aluminum garnet (Nd:YAG, 532 and 1064 nm).For the treatment of pigmented lesions short-pulse Q-switched and picosecond systems are typically used, including Nd:YAG (532 and 1064 nm), ruby (694 nm), and alexandrite (755 nm) lasers. 2 The main conflict with light-based technologies is between safety and efficacy.Higher energy fluence may result in greater thermal effect and thus more effective results, but it also increases the risk of adverse events and complications. 12IPL, a nonlaser device, offers rapid recovery time compared to laser treatments, lower equipment costs, and a larger area covered 13 as well as limited damage to surrounding tissue, 1 which can be attributed to the relatively low fluences. 14The broad wavelength output of IPL, typically in the 400-1400 nm range, allows few chromophores to be activated with a single light exposure. 12This versatility contributes to the ability of IPL to address multiple target chromophores, at different locations on the skin, simultaneously. 1,7On the other hand, such versatility implies reduced selectivity for the target chromophore 12 therefore, most IPL devices incorporate various cutoff filters that can eliminate wavelengths. 1 The selected wavelength, together with the precise pulse duration, will increase the selectivity in the photothermolysis process. 12For this reason, manufacturers have developed IPL technology with unique manipulations, and modifications of the pulse structure, focusing on safety while maintaining high efficacy. 12e current study used IPL technology, which delivers light energy from a precise narrow-band spectrum through a filter that limits the wavelength range to 450-600 nm.This ensures optimal absorption of hemoglobin and oxyhemoglobin in vascular lesions and melanin in pigmented lesions.The device used also features an advanced form of IPL technology-AFT.AFT converts unused UV light into the optimal spectrum, resulting in uniform energy delivery.This allows for more efficient use of energy per pulse, increased safety, longer applicator life, and improved clinical results.Simultaneously contact cooling was applied using a cold sapphire tip to further reduce the risk of superficial burns and ensure patient comfort during treatment.

E TH I C S S TATEM ENT
This study was approved by the Ethics Committee, Ministry of Health, Tirana, Albania.

CO N S E NT
This is a retrospective collection of anonymized data from previously recorded routine assessments and does not present risk of exposure of personal data of patients.Waiving informed consent will not adversely affect the rights and welfare of the subjects.Consequently, informed consent is not required, in agreement with the Albanian law.

| 3 ARMINDA
compared to the pre-treatment clinical photographs and rated the results on the Global Aesthetic Improvement Scale (GAIS) from 0 to 10, with 0 indicating much worse and 10 indicating much improvement.Patients rated their satisfaction with the results on a scale of 0-10, with 0 indicating complete dissatisfaction and 10 indicating complete satisfaction.

TA B L E 1
Demographics.ARMINDA favorable physician-reported GAIS scores, which were further supported by high patient satisfaction scores.None of the patients experienced pain during the study, and only two out of a hundred reported moderate side effects that resolved within a few weeks.A substantial positive correlation of 0.8 was discovered between patient satisfaction and physician assessment.This connection shows the agreement between the two measurements of effectiveness.

F I G U R E 2 3
Patient satisfaction scores, as assessed by the patients, for vascular and pigmented lesions.Pigmented Treatment areas before (A) and after (B) treatment with the IPL device.F I G U R E 4 Vascular Treatment areas before (A) and after (B) treatment with the IPL device.
scores, as assessed by the physician, for vascular and pigmented lesions.
The data indicate Note: Values are presented as follows: continuous variables-mean ± standard deviation; painnumber of patients reporting pain; satisfaction-on a scale of 0-10 as reported by patients; GAISon a scale of 0-10 as reported by physicians.