Photo-rejuvenation vs. Photo-modulation. Who and When?

photo-rejuvenation encompasses many procedures using light or laser-based technology to reverse the effects of photoaging. Non-ablative photo-rejuvenation refers to the controlled use of thermal energy to carry out skin rejuvenation without disturbing the overlying epidermis and with minimal to no downtime. Currently employed non-ablative modalities include primarily intense pulsed light (IPL), visible wavelengths including 585nm pulsed dye laser (PDL), and 532 nm green light (KTP laser). Different infrared wavelengths with water as the target are used for remodeling dermal collagen. The primary mechanism of action is thermal injury, either by heating the dermis to stimulate fibroblast proliferation or by heating blood vessels for photocoagulation. The newest way to deliver these wavelengths is by fractionating the dose. The non-thermal mechanism, which represents a fundamental change in thinking, is the theory of photo-modulation. This novel approach to photoaging uses non-thermal light treatments to regulate the activity of cells and not to invoke thermal wound healing mechanisms. The two types of Photo-facial (foto-facial) or Photo-rejuvenation are available are the Intense-Pulsed Light (IPL) and the Light-Emitting Diode (LED) treatments; however, to get the results you hope to do, it’s essential to understand the difference between these facial rejuvenation technologies before you book an appointment. Your best bet for minor skin problems is to schedule an LED (often called a non-IPL) treatment, and for more severe conditions, you’ll book to IPL.

What is Photo-rejuvenation/Photo-modulation

The gold standard for photo-rejuvenation, at least for fine wrinkles, has been ablative modalities. Although ablative tools can achieve predictable cosmetic enhancement, scarring, infection, dyspigmentation, and prolonged recovery times are less attractive. With the advancement of laser and non-laser light sources, photo-rejuvenation focuses on optimizing efficacy while minimizing recovery times.

Patients increasingly try to balance the efficacy of skin photo-rejuvenation within the downtime. Non-ablative skin photo-rejuvenation (NAR) typically mitigates injectable anesthesia and can often be performed with only topical or no anesthesia. Thus, non-ablative modalities have enjoyed a more significant role in skin photo-rejuvenation.


A clear definition of non-ablative skin photo-rejuvenation is essential because the term is sometimes used haphaz­ardly. Photo-rejuvenation improves skin quality without physical removal of the skin. At the same time, ablative modalities improve the skin via removal of a portion, or all, of the epidermis and sometimes may remove parts of the dermis.

Four basic approaches can selec­tively damage the dermis (and deeper epidermis):

  • They are targeting discrete chromophores in the dermis and at the dermal-epidermal junction.
  • I am using mid-infrared lasers in the 1.3- to 1.55-μm wavelengths. Water absorption is weak enough that deep beam penetration is allowed (there is only 50% beam attenuation at depths of 300 to 1500 μm).
  • Applying RF energy from the surface with cooled electrodes, temperatures are more significant in the dermis and fat than in the epidermis.
  • Non-ablative fractional lasers and RF needle devices deliver direct focal injuries to the skin with needles. These devices can perform multiple roles, from skin tightening to improvement in more superficial tone and texture (primarily dependent on the depth of the needle insertions).

Treatment of photodamage can be divided into various categories, and treatment protocols are based on a logical approach founded on the previous laser-tissue or RF–tissue interactions. The goal should be to maximize skin photo-rejuvenation from reducing telangiectasia and lentigines to enhancing dermal remodeling.


The laser and non-laser systems used for non-abla­tive photo-rejuvenation are a heterogeneous group of devices that emit wavelengths in the visible (400 to 760 nm), near-infrared (760 to 1400 nm), or mid-infrared (1.4 to 1.6 μm) ranges, intense pulsed light (IPL) devices, as well as light-emitting diodes (LEDs), and RF devices

Each of these tools can induce dermal remodel­ing, as well as target other components without epidermal ablation. Most investigators believe that photothermal heating of the dermis:

  • increases collagen production by fibroblasts and
  • Induces dermal matrix remodeling by altering glycosaminoglycans and other components of the dermal matrix. Others believe that the laser/light interaction with molecular and cellular components alters the cellular function of enzymes and cellular structural components.

Others believe that the laser/light interaction with molecular and cellular components alters the cellular function of enzymes and cellular structural components. Altering the different components of cells, from enzymes to cellular wall constituents to nucleic acids, may alter a given cell’s environment and productivity.

Photodynamic therapy (PDT) with aminolevulinic acid (ALA) has been shown to augment the effects of laser and other light sources in photo-rejuvenation.

Non-ablative skin photo-rejuvenation is commonly used to reverse photoaging in the dermis. This damage is directly correlated with the patient’s age and the extent of ultraviolet (UV) exposure. Ultraviolet B (UVB) light alters nucleic acids as it interacts with epidermal keratinocytes, inducing cellular atypia.

These UV-induced changes correlate with the clinical appearance of photoaged skin, including skin laxity, atrophy, and fragility, increased rhytid formation, telangiectasia, and alteration in the overall color, texture, and consistency of the skin. Thus, photo-rejuvenation aims to replace damaged epidermal and dermal constituents with more robust, newly created ones.

Photo-rejuvenation typically concentrates on improving fibroblasts’ function and durability. Photo-rejuvenation improves the quality of the skin cell keratinocytes and the pigment cells.

Although ablative skin photo-rejuvenation may achieve superior restoration of typical skin structures, especially for the Gloger grade III or IV patients, the downtime and potential risks are prohibitive for many patients. As non-ablative technologies evolve, restoring young, healthy skin with diminished risks and little recovery times is increasingly possible.

Phot-rejuvenation by Visible Light and Near-Infrared Laser

Visible light and near-infrared lasers are commonly used to treat vascular and pigmented lesions. Treatment of lesions with visible light lasers can achieve histologic correction of dyspigmentation, overall skin texture, dermal matrix abnormalities, and solar elastosis. Clinical improvement of solar lentigines, scars, including keloids and hypertrophic scars, and photoaging have all been observed.

Besides direct vascular heating and a resulting increase in dermal temperature, vessel targeting can also create an inflammatory cascade that results in new collagen formation. Commercially available PDLs emit wavelengths between 585 nm and 595 nm, penetrating deeper into the dermis and vessels. Newer PDLs have greater pulse duration ranges, generating pulse trains of up to forty ms, avoiding intravascular thrombosis in tiny vessels and subsequent purpura.


Other wavelengths that target hemoglobin in blood vessels have rejuvenated skin. The long-pulsed 755-nm alexandrite laser, the 810-nm diode, and the 1064-nm Nd: YAG lasers are used for more profound and larger-caliber vessels. The subsequent “coinciden­tal” dermal remodeling correlates with the depth of penetration of each respective laser.

Weng et al. have demonstrated that collagen synthesis by fibroblasts and antioxidant enzymes was significantly increased follow­ing irradiation with the 532-nm, 1064-nm Q-switched Nd: YAG, and 1064-nm long-pulse Nd: YAG lasers.

The 1064-nm Nd: YAG laser induces more profound remodeling than the 532-nm laser due to its lower degree of dermal scat­tering and chromophore absorption at 1064 nm. Thus, some physicians use multiple lasers, such as the 532-nm laser, to treat dyschromia and telangiectasia, followed by a pass with the 1064-nm laser to obtain some more profound remodeling in the same treatment session.

Near-infrared lasers have been used in a motion tech­nique for skin photo-rejuvenation. In one scenario, a 1064-nm laser equipped with a 5- or 7-mm spot size is deployed in a rapid back-and-forth fashion at 5 Hz and 12 to 15 J/cm2. The device is moved from region to region based on the surface temperature or when the heat becomes too uncomfortable for the unanesthetized patient.

photo-rejuvenation-modulation-BA crows feet
photo-rejuvenation-modulation-BA crows feet

Another tool for photo-rejuvenation is the Q-switched Nd: YAG laser, used in a motion technique at 5 to 10 Hz and 2 to 4 J/cm. The laser is applied with a 4- to 6-mm spot and multiple passes. The endpoints are mild erythema, and the laser can be applied in multiple sessions 2 to 4 weeks apart. A modest reduction in fine lines, scars, and dyschromia is often observed.

Other devices that heat the mid-dermis include halogen lamps and xenon flashlamps. The output of the former ranges from 1100 to 1300 nm, and the output of the latter ranges from 600 to 1200 nm. These devices straddle skin tightening and photo-rejuvenation applications, an arbitrary distinction in which tightening has been defined as overall skin contour enhancement. Like their laser near-infrared counterparts, the effect is gentle heating of the mid-dermis and upper hypodermis.

Adverse effects associated with all vascular lasers range from dyschromia, purpura, and blistering to scarring. Epidermal cooling techniques decrease surface heating and minimize pigmentary alteration. This addition is imperative in patients with Fitzpatrick IV to VI type skin treated with visible light lasers. Patients with a recent tan may also warrant a test spot. Epidermal cooling may be Mid-infrared lasers. Clinical and histologic evidence of non-ablative, nonfrac­tional skin photo-rejuvenation has been observed after using mid-infrared lasers.

The 1320-nm Nd: YAG laser was the first commonly used non-ablative mid-infrared laser to rejuvenate skin. The 1450-nm diode laser has been used for non-ablative photo-rejuvenation in the same way as the 1320-nm Nd: YAG. When combined with surface cooling, collagen remodeling is achieved without epidermal damage.

With water as the chromophore, the nonspecific dermal thermal injury creates edema, vascular changes, and alterations in fibroblast assembly of dermal matrix constituents. The healing sequence can result in mild correction of rhytids.

The 1540-nm erbium: glass laser similarly induces tissue water heating, thermal injury, and neo-collagenesis. This laser penetrates to a depth intermediate between 1320 nm (deepest) and 1450 nm (shallowest) in this wavelength range. In planning strategies with all the mid-infrared wavelengths, the penetration depth should coincide with the depth of solar elastosis.

Each non-fractional mid-infrared laser uses a cooling system to minimize epidermal damage and pigmentary alteration.

The side effect profile of each of these lasers directly correlates with the fluences applied in the treatment of rhytids or acne scars. The efficacy of these devices has proven modest in most cases, and providers must be cautious to avoid pigmentary changes and the rare case of scarring, which is typically secondary to treatment using a fluence that is too high.

Photo-rejuvenation by Intense Pulsed Light (IPL) and ELOS?

Intense pulsed light. Photo-rejuvenation

IPL devices emit a broad spectrum of wavelengths between 400 and 1200 nm to target multiple structures. IPL targets specific chromophores by using available filters to select within the 400- to 1200-nm range. Although not emitting monochromatic, collimated, or coherent light, these devices still use selective photo­thermolysis.

Shorter wavelengths can be used to treat lighter-skinned patients. The spectrum can be “redshifted” through filters or electronic modulation to minimize melanin absorption in darker-skinned patients. Peaks of hemoglobin absorption can be selectively used to target vascular structures.


The utility and potential risks of the IPL are associated with its diversity. Many available IPL units have a wide array of designs and treatment parameters. An IPL can treat the most clinically relevant chromophores (water, melanin, hemoglobin) and thereby multiple dermatologic condi­tions. Newer systems have improved by adding sophisticated graphical user interfaces with preprogrammed applications.

However, one should become comfortable with one or two IPL systems because each has different interfaces, wavelength spectrums, filters, power outputs, pulse profiles, cooling systems, and spot sizes. Some parameter sets do not allow different IPL systems to be easily compared. For example, some IPL devices calculate their fluences based partly on theoretical modeling and photon recycling. Others determine fluence based solely on an actual output at the sapphire or quartz window on the handpiece tip.

Finally, although the utility of IPL devices allows for the treatment of a wide variety of conditions, the addition of RF has been used to supplement and improve outcomes with the use of IPL devices (Elos, Syneron-Candela).

Electro-optical Synergy (ELOS) Photo-rejuvenation

Bipolar RF exhibits a preference for warmer tissue. This technology considers this property by using the IPL system to preheat the target chromophore and then using the RF technology to heat the tissue target further. Contact cooling helps to avoid epidermal damage. ElOS is and add to photo-rejuvenation armamentarium.


One of the goals of ELOS applications is to increase the ratio of dermal to epidermal heating by decreasing the optical fluence. This synergistic technology has shown its efficacy in the treat­ment of photoaging and in helping to reduce wrinkles, lentigines, and telangiectasias.

Light-emitting diode (LED) Photo-modulation


Light-emitting diodes (LEDs) for photoaging consist of a panel(s) of numerous small lamps that emit high-intensity light. Some companies have miniaturized these devices to handheld units used at home, whereas most professionals use panels that can treat the entire face in one treatment session. One advantage of LED devices is that patients tolerate them well. With no pain, It can treat large surface areas of skin simultaneously.

Typically LED devices emit a range of wavelengths. These devices are available in various wavelengths, from blue to infrared. Depending on the wavelength and treat­ment parameters, LEDs emit milliwatt light in a small range around a peak wavelength. Thus, for example, if one were to select an LED with a dominant wavelength of 500 nm, the device would emit light from 480 to 520 nm. However, more advanced LEDs with tight temperature controls are now available with smaller bandwidths and less wavelength “drift.”

The interaction of LED devices with the skin is unclear, although most believe that photo-modulation of cell recep­tors, organelles, or existing protein products is par­tially responsible. Unlike many of the devices discussed previously, nonthermal interactions with the extracellular matrix and fibroblasts remodel existing collagen, increase collagen production by fibroblasts, inhibit collagenase activity, and result in rhytid reduction.

One early LED system was the Gentle Waves device (Light BioScience, LLC, Virginia Beach, Virginia). The system generates 588-nm yellow light pulses with an on-time of 250 ms and off-times of 10 ms for 100 pulses, resulting in a total light dose of 0.1 J/cm2.

Although some trials showed significant improvement in pore size, skin tone, and texture, the most comprehensive controlled clinical trial showed no significant skin changes in objective outcomes after a series of treatments.


Boulos found a strong placebo effect with the 588-nm Gentle Waves system, and blinded raters observed slight objective improvement. Despite the subjective improvement in two trials, objective improve­ment in blinded studies is unproven.

In a 633- and 830-nm LED bio-stimulation study, two treatments showed increased collagen production and mild wrinkle improvement over four weeks. In a study using a reconstructed skin substitute irradiated with 633-nm LED panels, increases in collagen produc­tion were also observed. In addition, in the clinical arm of the study, patients receiving treatment three times a week for four weeks (12 treatments) were found to get mild-to-moderate wrinkle improvement compared with sham treatment.

How Photo-rejuvenation/Photo-modulation is Done?


Eye protection is placed on patients and provides people in the rooms are locked, appropriate signage is placed on it, and a pair of more glasses are left for staff to use if they come into the room during treatment. A topical anesthetic may be used and left on for a proper time and then washed off. The skin is cleansed of all makeup. One to 2 device activations are performed on the intended area, skin reaction assessed, and parameters adjusted based on response. The treatment is completed, and posttreatment sun avoidance and instructions are reinforced.

Non-ablative Fractional Laser Photo-rejuvenation

Their original device used this technology-induced column of necrosis within the epidermis and dermis while leaving the stratum corneum histologically intact and without removing any of the skin and was thus termed non-ablative fractional photothermolysis (NAFR).

One of the main advantages of NAFR is limited dis­comfort and minimal recovery after the procedure. In contrast to conventional resurfacing devices, fractional photothermolysis treats only a fraction of the skin, allow­ing for rapid repair from undamaged areas.

Although multiple treatment sessions are required to achieve the desired outcome, downtime is limited to 3 days of redness and swelling instead of an average of 7 to 10 days of an open wound after aggressive nonfractional ablative resurfacing. Combined with an excellent safety profile, NAFR has become the cornerstone of laser skin rejuvenation for the treatment of photoaging, acne scar­ring, and a variety of other clinical applications.

Fractional resurfacing is new, with advances in treatment parameters and innovative technology applications evolving every month. The technol­ogy is purported to cause limited epidermal disruption while creating a more comprehensive, conical injury zone within the dermis. Technological advances in fractional photothermolysis will continue to be made as the field evolves further.

Many patients have both pigmentary changes and rhytids associated with photoaging. A hybrid approach combining two non-ablative fractional resurfacing wave­lengths optimizes outcomes. Alternating 1927-nm with 1550-nm treatments addresses both concerns.

An alternative approach uses IPL to address photoaging dyschromia and uneven pigmentation, whereas 1550-, 1540-, or 1440-nm NAFR devices address wrinkling. Combining technologies in what is sometimes called “mega sessions” produces striking improvement in texture and color. Some combinations include NAFR preceded by Q-switched alexandrite laser, Q-switched Nd: YAG laser, long-pulsed green laser, or IPL.

Photodynamic therapy Photo-rejuvenation

Since 1999, photosensitizing agents have increased in medical and cosmetic dermatology. Twenty percent of 5-aminolevulinic acid (5-ALA, a “prodrug”) is absorbed by rapidly proliferating epidermal and dermal cells and converted into photoreactive products of the hemoglobin pathway most notably protoporphyrin IX (see Fig. 5.1). Protoporphyrin IX is subsequently activated by specific wavelengths of light, as highlighted by the absorption peaks, resulting in singlet oxygen production and resultant cellular destruction.

Many variables affect the immediate PDT response, among them the ALA incubation time, pre-ALA skin preparation regimen, degree of skin photodamage, anatomic region, light dose, wavelength range, skin temperature, and power density. This variety is owing to multiple absorption peaks by protoporphyrin IX. The most significant peaks are at 417, 540, 570, and 630 nm. The PDL, IPL, and LED devices have all been used to activate protoporphyrin IX.

Lower power densities (i.e., continuous wave light sources) create more singlet oxygen than pulsed light. In addition, we have found that applying anesthetic creams simultaneously with the ALA solution can accelerate ALA absorption and accelerate protoporphyrin formation, leading to a much more robust response.

Radiofrequency Motion Technique Large electrode-heating Devices

In the case of motion techniques, one moves the handpiece usually in a circular or back-and-forth fashion over areas ranging from approximately 5 × 10 cm2). For example, a specific region might be a cheek where for 5 to 10 minutes, the device achieves a surface temperature of 39°C to 42°C.


These temperatures are typically monitored externally by an inexpensive temperature monitor or a built-in tempera­ture sensor at the device’s tip. These procedures are carried out without topical anesthesia because feedback from the patient is essential in avoiding overheating the skin.

The intent is to establish a long-term-temperature combination that can initiate some modest neocollagenesis in the upper and middle dermis. These procedures are well-tolerated and safe, but results are often modest.

Radiofrequency Microneedling

Depths of penetration range from approximately 0.6 to 3.5 mm. Some devices deliver energy just along the surface, whereas others are depth-adjustable and can reach the dermal–subcutaneous junction. Both insulated and non-insulated designs are available.

The goal is to deliver focal injuries to the skin in a pattern of coagulation zones strategically placed to reverse the presenting pathology. One to three passes are typically made, depending on the specific technology.


Cross-sectional densities range from 5% to 20%. Often one will hear that RF devices are “color blind.” This is true for the surface-heating motion devices; however, if one applies the injuries superficially, post-inflammatory hyperpigmentation is possible for the needle devices.

A primary reason for skin aging is a loss of elasticity; RF needles, more than any other technology, enhance elastogenesis. The loss of elastic tissue in scars contributes to cosmetic and functional deficits.

How Many Sessions of Photo-rejuvenation/ Photo-modulation Do I Need?

After each treatment, patients can return to normal activities. The skin will be slightly pink when you leave but easily covered with makeup. Post care is accessible and may include ice pack administration to cool the patient’s skin immediately after the procedure.

I should use high-quality sunblock (sun protection factor 30+) daily, and avoiding outdoor activities after IPL treatment is minimal to zero. Low potency corticosteroid cream may be used for 2 to 3 days (twice a day) to increase comfort and shorten healing time. Patients must refrain from direct sun exposure for one week.

How Do I Look after Photo-rejuvenation/Photomodulation Skin Treatment?

The number of IPL photo facials you need will vary depending on the condition you are being treated, the results you want, and how your skin responds. Foto facials work best in conjunction with MSI skincare products developed for you. It can be offered as a stand-alone treatment or part of a more comprehensive rejuvenating MSI Peel. After the first series of treatments, more Foto-facial sessions are recommended once every 3 to 4 months to keep up with the results.

Overview of Photo-rejuvenation/ Photo-modulation Strategy

Patient selection is essential to obtain the best expectation–outcome match. Patients may be present to treat wrinkles and not the other characteristics of photoaging, even though telangiectasia or lentigines may be present.

The treatment modality is also essential as each light device offers unique advantages. For example, if the patient presents with a concern of excessive tel­angiectasia, I may warrant the use of the 532-nm KTP, a PDL, or an IPL device. If the goalkeeper dermal remodeling, one could consider longer-wavelength modalities, such as mid-infrared or RF devices.

Due to the widespread use and versatility of IPLs, many dermatologists are treating multiple photoaging charac­teristics simultaneously, including hyperpigmentation, telangiectasia, rhytids, and skin texture abnormalities.

Often a patient presents with multiple telangiectasias and actinic keratoses. If the patient presents with actinic keratosis or seba­ceous hyperplasia, PDT can be performed at the same appointment or before or after visible pulsed light treatment for red and brown dyschromia.

If one uses only a vascular laser or IPL, the actinic damage and the associated telangiectasias within the actinic keratoses will persist or relapse; accordingly, pretreatment with 5% fluorouracil cream or PDT will enhance the total photo-rejuvenation effect and decrease the likelihood of an incomplete response-.

With all lasers or light modalities, preparation of the patient and the clinical setting are essential. I should place all required items (gauze, gel, eye protection, etc.) on an easily accessible Mayo stand. The treating hand­piece should be cleaned according to the manufacturer’s instructions, and the device is positioned so that no cords or fibers are under tension.

Many physicians advocate pretreatment using a topical retinoid to maximize medical photo-correction and reduce the risk of dyspigmentation following treatment. Just before the procedure, I should cleanse the patient’s skin. Any residual debris, including oil, makeup, lotions, or topical anesthetics (if administered), may impede light delivery to the skin and be removed with alcohol. This alcohol should be allowed to dry before treatment completely.

The physician should always obtain pretreatment pho­tographs. The patient should be placed and draped to allow full access to the treatment area. This is typically achieved by placing the patient supine to treat such photodamaged areas as the face, neck, chest, and forearms. Appropriate goggles or eye shields (internal or external, depending on the treatment area) are then applied to ensure proper ocular protection.

It is helpful to inform the patient, even with appropriate eye protection, about the likelihood of seeing a flash of light during the procedure. Many patients become anxious regarding lasers when they see a flash of light, even when they have goggles or shields over them that they are protected puts them at ease.

The Conclusion

Non-ablative photo-rejuvenation remodels photodamaged dermal constituents without inducing an epidermal wound. Minimal recovery times make this approach appealing to physicians and patients alike. Reversal of dyschromia (pigment and vascular) is predictable. Unfortunately, at this point, in the eyes of many clini­cians, objective clinical and histologic outcomes with non-ablative technologies do not correlate with clinician expectations, except for novel fractional lasers and visible light technologies that target pigmented and vascular lesions.

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