Intense pulsed light (IPL) systems are mostly used for improving the skin texture from aging damages. This technology works by emitting a pulsed, noncoherent, polychromatic light through a filter, which can be changed according to the desired target within the skin. The side effects of these devices have been reduced, allowing its use for a wide variety of clinical indications. Currently, IPL devices are a safe and efficient treatment option for non-ablative skin rejuvenation, hair removal, and the removal of pigmented and vascular lesions. They are used in both professional and home laser hair removal devices.
Intense pulsed light (IPL) therapy is commonly used for the cosmetic improvement of the aging skin. In 1994, this device was first launched and promoted as a treatment option for leg telangectasias but had a limited utility due to the side effect profile. Throughout the years, technical modifications to this device have allowed it to be safer and easier to use, expanding its clinical use. Currently, IPL is a generally accepted treatment tool for non-ablative skin rejuvenation, photoepilation, and the treatment of pigmented and vascular lesions. It is regarded by some as the colloquial “jack-of-all-trades, master of none.”
This technology emits a pulsed, noncoherent, polychromatic light through a filter, which can be changed according to the desired target within the skin . Devices contain a xenon- flash lamp powered by capacitor banks controlled by microprocessors, which can alter the pulse duration. The broad spectrum of a flash lamp allows energy from multiple wavelengths (500–1,200 nm) to be emitted. Filters and parameters, such as fluence, pulse duration and pulse delay, can be adjusted by software to treat different targets, making it a versatile device.
- Chromophore – It is destroyed by the heat generated upon energy absorption. This should occur with minimal damage to surrounding structures when using adequate parameters.
- Filters – If changeable should be changed based on the target lesion’s depth within the skin, absorption spectrum of the desired chromophore and the patient’s skin type. Some devices require changing a particular delivery module.
- Pulse duration – Should be equal to the thermal relaxation time (TRT) of the target [ 8] , which is defined as the required time for a heated target to cool by 50 %. This dictates that smaller targets cool faster, requiring shorter pulses. For example, small collections of melanin within superficial pigmented lesions should be treated with short pulses, while deeper, larger melanin collections need longer ones. For vascular lesions, the pulse duration is approximately target size in millimeters squared. So for example, a 0.4 mm vessel would be treated with a 16 ms pulse.
- Can target multiple chromophores simultaneously.
- Can treat vascular lesions with minimal risk of purpura when compared to older pulse dye laser (PDL) therapies, which only have very short pulse durations.
- Can treat large body areas in short treatment sessions given its large beam size and rapid pulse rate.
- Bulky handpieces, making it difficult to treat certain areas of the face.
- Multiple treatment sessions might be required.
- Deeper lesions may be beyond the capability of the filtration or require too long a pulse, which can deliver too much infrared causing epidermal injury.
- Quality-switched lasers with nanosecond pulse durations provide greater selectivity for melanosomes and therefore higher efficacy for particular indications. Newer picosecond lasers are now entering the arena for treatment of pigmentation.
- Given the wide range of treatment parameters, it can lead to undesirable adverse effects if utilized by inadequately trained providers and with changing pigmentation of patients based on seasonal tanning.
- Hair removal by IPL has been shown in numerous studies to be safe and effective.
- Target: melanin within hair follicles (600–1,100 nm).
- Mechanism: Effective treatments require energy absorption and heat transfer from the hair matrix melanin to the stem cells in the bulge region of the hair follicle. This will produce collateral damage and eventual hair follicle destruction.
- Ideal candidates are light-skinned patients with dark hairs, as in darker-skinned patients, epidermal melanin competes with the hair follicle melanin for light absorption, decreasing treatment efficacy and increasing adverse effects.
- A report by Weiss et al., showed hair clearance to be 64 % after two treatments with a sustained hair reduction of 33 %, in patients with Fitzpatrick skin types of I–V.
- Long-term hair removal efficacy was found to be 76 % after a mean of 3.7 IPL treatments. Transient superficial crusting was reported in 6 % of patients, and temporary hyperpigmentation occurred in 9 %, but resolved within 12 weeks.
- Long-pulsed diode laser (LPDL) was compared to IPL for the treatment of hair removal in hirsute women, with IPL achieving best results, although not statistically significant.
- When compared to diode laser, it was found to be more effective, but the IPL was significantly less painful.
- Target: multiple.
- Mechanism: A nonablative approach that improves the overall appearance of aging skin, possibly due to remodeling of collagen fibers and neocollagenesis.
- The entire face should be treated, with treatment sessions generally performed at 3–4 weeks intervals for a total of three to six treatments. • IPL improved all aspects of photodamaged skin in 90 % of subjects with four treatments, and some up to six.
- N egishi et al. found greater than 60 % improvement in more than 80 % of patients after 5 or more treatments.
- L ong-lasting results were obtained after 4 years of initial treatment with 83, 82 and 79 % improvement in skin texture, telangiectasia and pigmentation components, respectively.
- Hedelund et al. found that three IPL treatments were effective in improving skin texture, telangiectasias, and irregular pigmentation, but had no effect on rhytids.
- Topical 5-aminolevulinic acid combined with IPL may have superior photorejuvenative effects than IPL alone.
- IPL may be used to treat acne and acne scars.
- Target: melanin and water, improving pigmentation, stimulating neocollagenesis, and destroying sebaceous glands.
- 7 patients were treated with 4–6 IPL treatments, followed by two sessions of fractional carbon dioxide CO 2 laser.
- Compared to baseline, IPL therapy reduced the inflammatory lesion and atrophic score, with even further improvement of the atrophic score with the fractional CO 2 laser. 80 % of patients rated their results as ‘excellent’ or ‘good.’
- Photodynamic therapy with topical 5-aminolevulinic acid and IPL has also been shown to be an effective treatment for moderate to severe acne, and superior to IPL alone.
Treatment of Vascular Lesions
- Can efficiently treat facial and leg telangiectasias, poikiloderma of Civatte, hemangiomas, and venous and capillary malformations.
- Target: hemoglobin, which absorbs at 418, 542, 577 and 800–1,100 nm.
- Mechanism: Visible blood vessels are replaced with fibrous granulation tissue after vessel coagulation and destruction.
- Multiple sequential pulses or multiple filtrations (in some iterations) with appropriate delay times provide adequate heating of blood vessels without harming surrounding structures.
- Small red facial telangiectasias can be treated with synchronized pulses. A first, short pulse should be used coupled with a second longer pulse. Duration and fluence should be gradually increased, with increasing vessel size.
- Bjerring et al. demonstrated that after 1–4 IPL treatment sessions, 79.2 % of patients achieved more than a 50 % reduction in the number of vessels, with 37.5 % achieving a 75–100 % reduction.
- Linear and spider telangectesias were treated in 140 patients by Retamar et al. with 67.1 % of patients having 80–100 % clearance.
- When compared to PDL, IPL was found to be equally safe and effective in treating facial telangiectasia in some studies.
- Adverse effects in the above mentioned studies were minimal. These included edema, erythema, and pain. Minimal hyperpigmentation that resolved within a month was reported in one patient. Purpura, hypertrophic or atrophic scars, or hypopigmentation were not reported.
Treatment of Pigmented Lesions
- IPL is useful in the treatment if superficial pigmented lesions. Other lesions that can be treated are ephelides, post-toxic epidermal necrolysis hypermelanosis, aberrant Mongolian spots, pigmented actinic lichen planus, and lentigines associated with LEOPARD syndrome.
- Target: melanin. It has a broad absorption spectrum (250–1,200 nm) but has the greatest absorption at lower wavelengths and it decreases with higher wavelengths.
- Filter: should be chosen based on the depth of the lesion. Lower cut-off filters along with shorter pulse durations are beneficial.
- Residual pigment can be treated with lower cut-off filters, higher fluences, and diminished skin surface cooling.
- Nevus spilus: Complete and sustained resolution after four treatments has been reported.
- Solar lentigines and macular melanocytic nevi: Single IPL treatments were performed, achieving pigment reduction in 96 % of patients; solar lentigines had an average clearance of 74.2 % and nevi, 66.3 %.
- Melasma: (there are no foolproof treatments for melasma)
– 89 Chinese patients with Fitzpatrick skin types III–IV received 4 treatment sessions with 77.5 % of patients achieving 51–100 % improvement .
– A study demonstrated that a single IPL treatment combined with triple combination topical therapy (hydroquinone 4 %, tretinoin 0.05 %, fluocinolone 0.01 %), was more effective than the use of topicals alone for refractory mixed and dermal melasma in patients with Fitzpatrick skin types II. Of these patients, 3 with malar melasma and skin phototype IV, developed postinflammatory hyperpigmentation that resolved with the use of bleaching agents for 4–6 months.
- Complete elimination of facial dyspigmentation is rare with IPL alone, and alternate laser treatments, such as Q-switched devices, can be added to obtain best results.
IPL should be avoided in:
- Women who are pregnant or are breastfeeding.
- Patients receiving systemic retinoids.
- Patients receiving photosensitizing medications.
- Patients suffering from a disease or genetic condition that results in photosensitivity.
- Avoidance of tanning before therapy.
- Informed consent should be obtained for all patients. The risks, benefits, side-effect profile, and alternatives should be discussed.
- The area being treated should be clean and shaved if needed.
- Topical anesthesia is generally not required, but may be used if needed.
- Safety goggles and/or eye coverings should always be worn by the practitioner and patient.
- A 1–2 mm layer of cold ultrasound gel or aloe vera should be applied to the treatment area.
- A 10 % overlap between pulses is recommended.
- Positive clinical end points:
– Vascular lesions: disappearance or a darker blue appearance of telangiectasias, as well as brightening or smudging of the lesions.
– Pigmented lesions: will darken with effective therapy.
– Hair removal: perifollicular edema and erythema.
- An initial or test pulse should be performed to determine the response to therapy. If adequate, start performing multiple passes at different angles
- Patients should be instructed to avoid sun and use sun protection.
- They should also be instructed to provide gentle skin care.
- Patients are normally followed-up and/or treated at 4–6 weeks interval.
Common Side Effects
- Pain: described either as a stinging, brief grease splatter, or electrical shock.
- Burning sensation: usually mild and lasted less than 10 min in 45 % of patients.
- Erythema: lasted several hours to up to 3 days. In full-face treatments, 25 % had mild cheek swelling or edema lasted 24–72 h.
- Dyspigmentation: hyper- or hypopigmentation lasting less than 2 months was described in 8–15 % of treated sites.
- Crusting: 2 % of patients developed scattered crusting in areas of increased pigmentation, and peeled off within 7 days.
- Purpura: was noted in isolated pulses in about 4 % of cases.
Serious Side Effects
- Blister formation
- Permanent pigmentary alterations
Prevention of Management and Complications
- With the use of appropriate filters and parameters, selectiveness of treatment is achieved, minimizing collateral damage to surrounding structures.
- By using higher filters (550 or 560 nm) when treating poikiloderma in patients with significant dyspigmentation, major epidermal absorption is avoided, minimizing the possibility of excessive swelling and crusting.
- Gel use (water-based) is recommended to minimize epidermal damage by decreasing the refraction index of light to the skin. It also promotes a “heat-sink” effect and facilitates the gliding of the hand piece.
- Test pulsing is highly recommended as it helps determine the ideal parameters to provide best results with minimal side effects. Some signs that may indicate treatment parameters are too aggressive are: immediate purpura, excessive blanching, pronounced edema, blistering, graying, or excessive discomfort. Waiting 30 min after a test pulse is recommended to assess potential side effects.
- Performing multiple passes at different angles avoids f ootprinting of the crystal outline or what is sometimes referred to as zebra pigmentation.
- Darkly pigmented patients (Fitzpatrick skin types IV–VI) require lower fluences, longer wavelength filters, and longer pulse widths.
- Purpura most often results with use of a 515 filter or with too short pulse durations.
IPL devices are versatile, non-invasive light-based systems that can successfully treat a wide range of skin conditions that continues to expand as technology improves. It has gained popularity as a cosmetic and medical device, due to prevalence and decreased cost of ownership as well as increasing evidence supporting safety and efficacy when used by appropriate personnel. Unfortunately, non-selective thermal damage is always a risk that is increased when IPL therapy is provided by untrained or insufficiently trained practitioners. Therefore, a comprehensive understanding of mechanism, design and subtlety of different IPL devices, as well as parameters and indications is highly desirable in order to provide safe and successful treatments.