The relationship between light and health has been observed for millennia: Hippocrates often advised his patients to expose themselves to sunlight to treat a variety of ailments. Herodot, a citizen of ancient Cairo, opined that the strength of the human skull was related to amount of sunlight to which a person was exposed (vitamin D?) In more recent times, light (or rather lack of it) has been recognized as causative in seasonal affective disorder (SAD), a depressive condition in which lack of light upon the retina decreases CNS secretion of melatonin and serotonin.
Light has found a home in medicine for more than a century. It was first employed as a skin treatment in 1895 when a carbon arc light source was used to treat a patient with lupus vulgaris. Ultraviolet phototherapy has been a recognized treatment for a number of skin conditions for decades, psoriasis, eczema, and pityriasis rosea among them. Neonatal jaundice has long been treated using artificial blue light. It has been used to treat acnes since 1978 and SAD since the 1980’s.
Light, in numerous manifestations, found a home in aesthetics years ago. It is one of the most widely used forms of energy in skincare with new modalities constantly evolving. Let’s take a look at the role of light in aesthetics – how it’s used and what benefits it offers.
The Miracle of Lasers
The word laser is an acronym for Light Amplification by the Stimulated Emission of Radiation. The light emitted is profoundly different from sun light, or light emitted by common artificial light sources. Laser light can be immensely intense, powerful enough to cut through steel or destroy a rocket in mid-flight. It can also be incredibly precise and delicate, even used to cauterize tiny bleeding vessels in the retina of the eye. Lasers are now everywhere: office copiers, surveying equipment, computer mice, industrial measurements, even “pointers” to direct an audience’s attention to PowerPoint slides.
The laser was invented in 1957 by a graduate student in physics at Columbia University. He devised a cylinder with mirrors at both ends facing inwards, with one of the mirrors being slightly less reflective than the other. His theory was that when a light source was introduced, the light source within the cylinder would bounce back and forth, gaining energy to the point that some of the light would emerge through the less reflective mirror. He was right, although now lasers have two highly reflective surfaces with one of them having a small transparent window to allow light to emerge. In more technical terms:
“A laser is an optical oscillator, which is made out of a solid, liquid or gas with mirrors at both ends. To make the laser work, the material is excited or “pumped,” with light or electricity. The pumping excites the electrons in the atoms, causing them to jump to higher orbits, creating a “population inversion.” A few of the electrons drop back to lower energy levels spontaneously, releasing a photon (quantum of light). The photons stimulate other excited electrons to emit more photons with the same energy and thus the same wavelength as the original. The light waves build in strength as they pass through the laser medium, and the mirrors at both ends keep reflecting the light back and forth creating a chain reaction and causing the laser to “lase.”
The combination of spontaneous emission first, and then stimulated emission, causes the laser to “lase,” which means it generates a coherent beam of light at a single frequency. The wave length of the light emitted is dependent upon the substance being used to generate the photons within the laser. Wavelengths are measured in nm (nanometers) and lasers in medicine have particular clinical applications that are best treated using machines with certain wavelengths.
Lasers in Aesthetic Medicine
The unique ability of optical technologies to target specific structures and layers in tissues to cause chemical, mechanical, or thermal changes makes them a powerful tool in cutaneous rejuvenation, hair removal, fat removal, and treatment of vascular lesions such as port-wine stains, among many other procedures. With the development of epidermal cooling, lasers and optical technologies have become more versatile and safe. They are constantly being improved to provide safer, easier, more quantifiable, and more individualized therapy.
Lasers have become particularly useful in the management of photoaging, with protocols involving single or combination systems depending on degree of skin damage. Treatments can be aggressive with extensive tissue damage, significant healing “downtime”, and increased risks of untoward pigmentation and scarring, or superficial and subtle, sometimes requiring multiple treatments to achieve desired results. In recent years, there has been a trend toward less invasive or minimally invasive treatments, with the aim of reducing the risk of side effects, complications, and downtime.
A compromise treatment utilizes fractional resurfacing or photothermolyis, where the laser injuries are tiny and performed in a grid-like pattern, leaving large percentages of undisturbed skin.. These are less aggressive than CO2 resurfacing and result in much less patient down-time. The physician tailors the skin resurfacing procedure to each person’s unique needs. The technology can be used on light, medium and deep settings depending on the amount of improvement and the number of days for complete rehabilitation along with the number of treatments desired. It does not have the previous CO2′s high risk of discoloration, long healing times and prolonged erythema.
Obviously, lasers and light-based treatments alone might not be sufficient to control all aging symptoms. For this reason, many other treatments (botulinum toxin, dermal filling agents, chemical peels, systemic and topic Improved therapeutic results. Overall, there is a transition in antiaging aesthetics from aggressive surgical interventions like facelifts, to more natural looking and subtle changes.
Most Common Lasers Used in Medical Aesthetics
The CO2 laser system works on 10600 nm wavelength and can be used in several ways: “focused” for cutting skin without bleeding; “defocused” for superficially vaporizing skin; and “ultra pulsed” for facial resurfacing. By delivering very powerful, rapid pulsing or scanning of the latest generation of CO2 lasers, laser surgeons are able to resurface the skin for cosmetic improvement. This technique removes fine lines and wrinkles of the face, smoothes acne scars, and rejuvenates aging and sun-damaged skin as it contours the skin surface. When the CO2 laser’s energy is defocused and not continuous (pulsed), the dermasurgeon can treat warts, shallow tumors and certain precancerous conditions. When the CO2 laser energy is continuous and focused into a small spot of light, the beam is able to cut the skin. It is used in this way to remove skin cancers, to treat a variety of non-vascular and pigmented lesions and for eyelid operations. This technique is also used to remove warts and for some surgical incisions.
Erbium (Er:YAG) Laser
One of the latest tools available for the treatment of wrinkles, acne scars, aged and sun-damaged skin, the Erbium is a cool light laser that resurfaces the skin. This method results in less post-procedure redness, less swelling and faster healing time and much less risk of side effect than with other strong laser skin resurfacing methods. The Erbium laser can be used on the face, neck, chest and hands. The erbium:YAG 2940 nm (Er:YAG) laser produces energy in a wavelength that gently penetrates the skin, is readily absorbed by water and scatters the heat effects of the laser light. These properties enable laser doctors to remove thin layers of aged and sun-damaged skin tissue with exquisite precision while protecting healthy surrounding tissue. The Er:YAG laser is commonly used for skin resurfacing to improve moderate facial wrinkles, mild surface scars or splotchy skin discolorations. Newer Er:YAG lasers have an extended pulse duration that allows them to act in a similar manner to the CO2 laser.
Through the use of an organic dye, short pulses of yellow-colored light (578 nm) are produced. A popular yellow light laser is the pulsed dye laser. Because yellow light is more precisely absorbed by the hemoglobin than other colors, these lasers are effective in the treatment of blood vessel disorders, such as port wine stains, red birthmarks, enlarged blood vessels, rosacea, hemangiomas and red-nose syndrome. Certain yellow light lasers may also be used to treat stretch marks and are safe and effective for infants and children.
Green Light Laser
The green light (511 nm), in contrast, is used for the treatment of benign brown pigmented lesions, such as café-au-lait spots, the “old age” spots commonly found on the backs of the hands and lentigines or freckles. Green light lasers are also used for the treatment of small blood vessels on the face and legs.
Red Light Laser
The red light spectrum produced by the ruby or alexandrite light laser is emitted in extremely short, high-energy pulses due to a technique known as Q-switching. The Q-switched ruby or alexandrite laser systems were initially used to remove tattoos, but are now commonly used to treat many brown pigmented lesions, such as freckles or café-au-lait spots.
When the pulse duration of the ruby or alexandrite lasers is lengthened, it is effective in removing unwanted hair for long periods of time, sometimes even permanently.
Q-Switched Neodymium YAG (Nd:YAG)
Delivering infrared light, it is used to remove tattoos and deep dermal pigmented lesions, such as nevus of Ota. This laser can also be tuned to produce a green light for the treatment of superficial pigmented lesions like brown spots, as well as orange-red tattoos.
The KTP emits a green light and is capable of treating certain red and brown pigmented lesions. When the pulse duration is lengthened, the Nd:YAG laser is also effective in removing hair and an inflammatory condition termed pseudofolliculitis barbae for months and sometimes permanently. This is particularly useful in the treatment of dark-skinned patients.
Non-Ablative Lasers and Light Sources (IPL)
Instead of heating and removing the top skin tissue, non-ablative (non-wounding) lasers work beneath the surface skin layer to improve skin tone and texture and minimize fine lines with few side effects and a speedy recovery. Light-based devices that produce a broad spectrum of light (wavelengths) with computer-controlled parameters of energy delivery (Intense Pulsed Light, or IPL) can be adjusted according to a patient’s skin type and condition. This technology is primarily used for the treatment of benign red and brown lesions, hair removal and facial skin rejuvenation.
Results Can Indeed be Impressive
Cautions and Contra-indications
Certain skin conditions, health irregularities, and medications can impact whether it is safe for a person to receive a light based treatment. This list applies to both IPL and conventional laser treatments.
- Recent use of depilatory creams or sprays
- Recent waxing, tweezing, or sugaring
- Contagious skin diseases: not always contraindicated but requires special preparation
- Herpes I and II in the area to be treated: not always contraindicated but requires special preparation
- Skin trauma, lesions, sores or open wounds
- Keloid or hypertrophic scarring
- Moles or skin cancer: treatment can blanch skin marks, making melanoma difficult to detect
- Suntan, real or fake: hyperstimulates melanin in skin which provides a confusing target for light
- Epilepsy or other seizures potentially caused by flashing light
- Polycystic Ovarian Syndrome (PCOS): condition needs to be normalised with medication before treatment
- Hyperthyroidism: condition needs to be normalised with medication before treatment
- Breastfeeding and pregnancy: increased hormone levels greatly decrease treatment efficacyHirsutism: not contraindicated but will require a greater number of treatments]
- Tattoos or permanent makeup in area to be treated
- Photo-sensitising topical creams or medication: Tetracycline, Minomycin, Doxycycline, St John’s Wort, any citrus essential oils
- Black garments: can singe or combust if struck directly by the light flash
- Pain during treatment: if a person feels more than mild discomfort during treatment, the machine settings are wrong
- According to Remington, manufacturer of an IPL hair remover, all IPL and laser devices should only be used on light to medium skin tones, and work best on darker hair.