Intensive Pulsed Light

Pulsed light is a flash light with multiple wavelengths and high energy, and it stably emits the complete spectrum of light in the wavelength of 500–1200 nm. It covers almost all wavelengths of common lasers and amounts to a combination of all lasers; therefore, it is also called “third-generation laser.” Unlike lasers that use a single wavelength to treat skin lesions at the same depth, this composite light wave realizes transition among different pulses within the available light spectrum by selecting different wavelengths of lights and thus allows it to be flexibly used for treating numerous skin problems in different layers and render remarkable effects in removing spots, lightening chromophores, shrinking pores, removing hairs, and clearing vascular lesions. Moreover, its large-area probe can also be used for whole face cosmetic phototherapy, and it is a multifunctional revolutionary device. In particular, for patients with complex skin problems, it still commands an irreplaceable status.

New-generation pulsed light apparatuses all belong to adjustable devices that simultaneously output multiple wave bands, whose efficacy almost covers various laser treatments in depth and scope. It not only allows physicians to select appropriate pulse wave bands and energy output in light of various types of skin problems to match treatment objectives but also does not inflict deep skin damage similar to a single wavelength laser because of its stable and mild energy output. Therefore, it does not leave any epidermal wound, does not require a recovery time, rarely induces sequelae such as darkening or scarring, and is extremely suitable to patients desiring comprehensive and progressive skin improvement. Currently, all new pulsed light apparatuses have in-built parameters for various skin problems and are furnished with probes of different wavelength for switchover, which further elevate the efficiency and safety of the treatment. Based on the distribution characteristics of pulsed light wave bands and hand-held probe types, our clinic offers treatment services for the following skin problems:

Phototherapy rejuvenation SR (560- and 640-nm wavelength)

This is also called cosmetic phototherapy and is the most widely acknowledged and applied function of pulsed light. Based on the mild broadband spectrum and homogenous irradiation depth of pulsed light, it utilizes light at a relatively low wavelength to treat superficial skin spots or chromophores and concurrently uses light at a relatively long wavelength to stimulate hyperplasia of collagen or elastic fibrous proteins in the dermal layer, thus improving skin aging and pore or fine line problems. This phototherapy should be conducted for the entire face and solves numerous complex skin spots and skin conditions at the same time. Because the treatment mildly progresses, each lasing does not leave wounds or marks on the face, and patients would still wear normal makeup and go to work the next day; it is therefore considered as the first option of “lunch-break cosmetics.” Nevertheless, patients need to return to the clinic for treatment every month. Generally, 3-4 treatments are needed against skin spots or vascular marks, and approximately 6 courses are needed for the treatment of pores or fine lines to attain stable and obvious results.

According to Dr. Chuang’s experience and observation, pulsed light of the above wave bands are most effective for superficial spots, such as freckles or sunburns, having a clearance rate of over 80%, but it shows less distinct effects on chloasma hepaticum, nevus zygomaticus, or pigmentation. To improve skin conditions, shrink pores, whiten skin, or smooth fine lines, 6 treatments are generally needed, and pulsed light therapy needs to be conducted every 2-3 months to achieve results, thus sustaining the efficacy of phototherapy rejuvenation and preventing the reoccurrence of spots.

General instructions

Preoperative

  • Suspend the use of healthcare products or drugs containing retinoic acids for 1 week preoperatively.
  • It is forbidden in patients with active acnes or acute infections of the skin.

Postoperative

  • Enhance skin moistening and care after 1 week.
  • Resume drugs containing retinoic acids after 1 week.
  • Avoid staying up late, smoking, or fried food during the treatment to facilitate the rapid onset of results.
  • Reinforce daily skin sunscreen and ultraviolet insulation during and after the treatment.

Ideal candidates

  • Patients with skin spots at uneven depths
  • Those with skin pigmentation or inhomogeneous skin color
  • Those with dark or yellow skin
  • Those with coarse and oil-producing pores, fine lines, or rough skin
  • Those unable to accept the wounds or recovery time of laser treatment
  • Those who underwent laser treatment resulting in darkening

Potential complications

  • Temporary scarring
  • Uneven skin color
  • Skin redness

Treatment advantages

  1. It is able to simultaneously alleviate numerous skin problems and achieve the results of skin whitening, spot lightening, and skin toning.

  2. No wound or mark is left postoperatively, and there is no constraint of recovery time.

  3. Treatment is mild and not destructive and rarely has risks of darkening or scarring.

  4. No special wound care or maintenance is needed after the operation.

  5. The physician adjusts the pulsed light energy based on the response to the previous treatment, making the administration safer and more flexible.

  6. It is given to patients of any skin color or skin conditions.

  7. It is repeatedly conducted without any limitation to sustain the optimal skin conditions.

Treatment drawbacks

  1. Patients need to receive 4–6 treatments, so the treatment duration is relatively long.

  2. Treatment results may differ due to physician experience, parameter setup, or patient skin conditions.

  3. It is less effective against deep skin spots or chromophores (<20%).

  4. Improvement rate for pores or fine lines reaches only 30–40%.

  5. Durability of postoperative results may differ along with individual daily skin care.

  6. It is contraindicated for patients with skin light sensitivity

Chromophore model PL (515-, 550-, 570-, 590-, 615-, and 645-nm wavelength)

The chromophore model utilizes pulsed light in the wavelength of 500–600 nm to lighten various skin color patches or spots such as freckles, aging spots, sunburns, nevus zygomaticus (or black spots), or even pigmentation and birth marks. Unlike laser spot removal that directly damages the epidermis of the superficial skin, it is based on mild light thermal irradiation to a large area to stimulate the gradual emulsion of skin spots at different depths and allow them to be naturally metabolized by the human body. Therefore, no wound would be left, and the spots irradiated by the pulsed light would be tiny scars similar to coffee powder for 1 week postoperatively, which would be shed in the following 2-3 weeks, with the results able to be ascertained in approximately 1 month. The chromophore model entails the gradual accumulation of energy to treat relatively deep spots or pigment problems, and generally, 3-4 courses are needed to attain stable and obvious spot lightening and homogeneous skin color.

Compared with the rejuvenation model, the chromophore model is specific in the treatment of spots, so the energy is higher; thus, the improvement of superficial freckles or sunburns is most rapid and distinct where only approximately 2 courses could clear 70–80% of the spots. However, it is less effective against black spots such as nevus zygomaticus or chloasma hepaticum because 4 courses of treatment only deliver a clearance rate of 30–40%. The results in the treatment of pigmentation, laser darkening, or birth marks differ along with individuals. If there are residual spots after 4 chromophore model treatments, patients should consider undergoing laser spot removal.

General instructions

Preoperative

  • Suspend the use of healthcare products or drugs containing retinoic acids for 1 week preoperatively.
  • It is forbidden in patients with active acnes or acute infections of the skin.

Postoperative

  • Enhance skin moistening and care after 1 week.
  • Resume drugs containing retinoic acids after 1 week.
  • Avoid staying up late, smoking, or fried food during the treatment to facilitate the rapid onset of results.
  • Reinforce daily skin sunscreen and ultraviolet insulation during and after treatment.

Ideal candidates

  • Patients with congenital freckles
  • Those with skin spots at different depths
  • Those unable to accept the wound or recovery time of laser treatment
  • Those who underwent laser treatment resulting in darkening

Potential Complications

  • Temporary scarring
  • Skin sensitivity
  • Redness
  • Chromophore darkening

Treatment advantages

  1. The treatment is able to treatment various skin spots at the same time and effectively achieves spot lightening and skin toning effects.

  2. No wound or mark would be left on the skin postoperatively, and no recovery time necessary for laser spot removal is required.

  3. Treatment is mild and not destructive and is less likely to cause darkening.

  4. No special wound care or maintenance is needed postoperatively.

  5. There is no limitation on skin color or condition.

Treatment drawbacks

  1. Patients need to receive 3-4 treatments, so the treatment duration is relatively long.

  2. It is less effective against deep skin spots (such as chloasma hepaticum, black spots, or pigmentation) (only approximately 30–40%).

  3. Treatment results may differ due to physician experience, parameter setup, or patient skin conditions.

  4. Spots may recur due to sun exposure or inadequate application of sunscreen.

  5. It is contraindicated for patients with skin light sensitivity.

Comparison between  Intensive pulsed light and laser spot removal

Intensive Pulsed light sot removal Laser spot removal
Ideal candidates Patients with multiple or irregular spots or chromophores Patients with independent or deep spots or chromophores
Treatment device Intensive Pulsed light chromophore mode probe Q-switch neodymium-doped (Nd):YAG or ruby laser
Treatment principle Melanin thermal condensation Mechanical photoacoustic epidermal injury and thermal condensation
Acting wavelength Continuous wavelength, adjustable Single wavelength, fixated
Action depth Epidermis and dermis Epidermis
Treatment scope Square or rectangular homogenous heat source Spot blast
Skin wound No Temporary injury (5–7 days)
Pain Low Relatively obvious
Number of treatments 3-4 times on average Approximately 1-2 times
Result onset Relatively slow Fast
Treatment characteristics Able to lighten both deep and shallow spots or chromophores Mainly used for the treatment of deep spots or tattoos or removal of moles
Skin improvement Able to concurrently whiten the skin No
Recovery time No 5–7 days
Darkening risk Low Relatively high
Postoperative nursing No special caring is needed Application of sunscreen or insulation should be highlighted

Vascular mode (515-, 550-, 570-, 590-nm wavelength)

Based on its penetration energy of homogenous irradiation, Intensive pulsed light can also be used for the treatment of numerous superficial facial thread veins such as congenital port-wine stains, microaneurysms, spider veins with exposed capillaries, capillary marks having a predilection for both alar sides, or even red face caused by rosacea, seborrhea, or chronic skin sensitivity. As the energy of pulse light in the wavelength of 580–600nm can penetrates the subcutaneous layer by up to 5–8 mm, it instantly closes and shrinks capillary walls via tepidity effects to rapidly make the capillaries originally predisposed to blood congestion become narrow and atrophic. This vascular treatment presents higher depth and energy than the common chromophore model, but it still retains the mild and scarless characteristics; therefore, it is less likely to induce pigmentation or uneven color spots and other sequelae seen in the traditional vascular staining laser. The number of treatment courses is flexibly adjusted based on the characteristics of patient lesions, but generally, 4–6 courses are necessary to achieve an improvement rate of over 50%.

General instructions

Preoperative

  • Suspend the use of healthcare products or drugs containing retinoic acids for 1 week preoperatively.
  • It is forbidden in patients with active acnes or acute infections of the skin

Postoperative

  • Enhance skin moistening and care for 1 week.
  • Resume drugs containing retinoic acids after 1 week.
  • Reinforce daily skin sunscreen and ultraviolet insulation during and after the treatment.
  • Try to avoid high-fat, spicy, or fried food during the treatment to facilitate the rapid onset of results.

Ideal Candidates

  • Patients with congenital microaneurysms or port-wine spots
  • Those with obviously thread veins at the nasal tip or bilateral alar sides
  • Those with prolonged red cheeks due to seborrhea, rosacea, or skin chronic sensitivity
  • Those with dark or black lips due to microvascular stasis
  • Those unable to accept the risks and recovery time of a staining laser

Potential complications

  • Temporary skin redness
  • Desquamation

Treatment advantages

  1. The treatment is mild and progressive and is free of pigmentation possibly seen using the vascular laser.

  2. No wound or mark would be left postoperatively, and there is relatively no limitation to the recovery time.

  3. No special wound care or maintenance is necessary after the operation.

  4. It partially improves light allergy.

Treatment drawbacks

  1. Patients need to receive 4–6 treatments, so the treatment duration is relatively long.

  2. The average clearance rate reaches only approximately 50–60%.

  3. Treatment results may differ due to physician experience, parameter setup, or treated site conditions.

  4. Hemangioma may recur or enlarge after treatment.

  5. Treatment results may appear relatively indistinct in patients with dark skin.

Hair removal mode HR (695-, 755-nm wavelength)

With relatively high wavelength of pulsed light (700–800-nm red light) and stronger energy, it allows thermal energy to effectively penetrate into the skin to the inferior epidermal layer and make the follicles rich in melanin shrink or become atrophic, thus achieving the purpose of permanent hair removal. Therefore, as long as they are actual hairs (except fine hairs), regardless of the large-area hairs at the armpits, perineum (bikini line), hairline, forearm, or even calf, they are effectively removed by the hair removal mode. Compared with traditional laser hair removal (such as ruby or Alexander laser), pulsed light has a broader spectrum of light waves of different colors and better thermal permeability, whose results are less likely to be affected by race, skin color, or hair site. Moreover, the large probe of pulsed light can also expand the treatment scope and enable the affected site be homogeneously heated and is less prone to incur folliculitis or hair residue. Regarding its drawbacks, the treatment results are inferior to laser hair removal in the treatment of thin hairs; the number of treatment courses is relatively higher, and treatment results differ due to energy adjustment by the physician.

According to Dr. Chuang’s experience, pulsed light is most effective against thick hairs (such as armpit or leg hairs) but is not significant against thin or fine hairs (such as female fake beards or hand hairs). Generally, multiple courses are necessary to reach a clearance rate of over 90% (permanent hair removal), and the first 2-3 courses demonstrate the most distinct effects as they are able to remove approximately 30% of the hairs at each course, but the results gradually wane due to the growth period of hairs. Besides, the number of treatments for hairs at different sites also differs. Generally, 4–6 treatments are needed for armpit and perineal hair removal and 6–8 times are needed for forearm hairs; as calf hairs are abundant and widely distributed, over 8 treatments are usually required, which should be conducted at an interval of at least 1 month.

General instructions

Preoperative

  • It is contraindicated for patients with open wounds or acute infection at the skin of treated site.

Postoperative

  • Abstain from other mechanical hair shaving or shedding activities during treatment.

Ideal candidates

  • Patients with exceedingly low forehead hairlines
  • Those with abundant armpit, perineal, or extremity hairs (thick hairs)
  • Those with whiskers or abundant facial hairs

Potential complications

  • Temporary skin redness
  • Uneven skin color
  • Folliculitis

Treatment advantages

  1. Compared with laser hair removal, it is less painful and leaves no traces.

  2. Treatment is extensive and homogeneous and is less likely to cause hair residue or omission.

  3. Treatment results are stable and less likely to be affected by skin thickness or skin or hair color.

  4. Progressive hair removal effectively covers the growth cycles of various hairs, with a low hair regrowth rate (<10%).

Treatment drawbacks

  1. Numerous treatment courses are needed and it is relatively long.

  2. Less effective against thin or fine hairs

  3. Number of treatments may differ along with quantity of individual hairs.

  4. The physician’s experience or energy setup may affect hair removal effects.

Comparison between Intensive pulsed light and laser hair removal

Intensive Pulsed light hair removal Laser hair removal
Ideal candidates Patients with large-area or excess hair Patients with regional hair hyperplasia
Hair removal device HR hair removal mode probe Ruby or Alexander laser
Treatment principle Follicles become atrophied due to heat trapping Follicles are damaged due to photoacoustic effects
Wavelength 512–1200-nm continuous wavelength Single 694- or 755-nm wavelength
Action depth Relatively deep Relatively shallow
Treatment scope Square or rectangle homogenous heat source Spot or circular heat source
Number of courses Dependent on treatment site; approximately 6–8 times 3–5 times on average
Result onset Relatively slow Rapid
Treatment characteristics Remarkable effects against thick or black hairs Both thick or black hairs could be removed
Follicle residual rate Relatively low Relatively high
Hair re-growth rate <10% <5%
Folliculitis Low Probable