Light-based therapy has become the darling of cosmetic medicine, with such treatments holding the key to treating a wide variety of skin, fat, tissue and hair afflictions. So what are your options?
Light therapy’s wide range of applications has made it a popular modality amongst consumers and medical and beauty practitioners. For cosmetic indications, light-based treatments can be broadly categorised as intense pulsed light therapy, photodynamic therapy and laser therapies.
Laser
Laser light is different to normal light for many reasons: it travels in a synchronised fashion; retains its intensity over a long distance; is monochromatic (of the same wavelength or colour) and it can be pulsed.
Laser therapies work by targeting tissue and can be used for a number of treatments, including pigmentation, scarring, unwanted hair, spider veins, sun-damaged skin, wrinkle reduction and overall complexion rejuvenation.
The principle behind lasers is light absorption. The same as a black car will be hotter than a white car because it absorbs more wavelengths of light, certain target tissues will absorb certain wavelengths of light more effectively. As the laser light is monochromatic the target tissue will take on maximum absorption while the surrounding tissues won’t. This allows the target to be isolated and treated. In other words, the laser emits a single frequency of light with all the light waves going in the same direction, allowing the target tissue to absorb the maximum amount of heat.
The target tissue is all-important when treating skin problems with a laser. For pigmentation it is melanin; for spider veins and other vascular conditions it is haemoglobin (blood); and for wrinkles it is water. Each of these target tissues absorbs a different wavelength of light, meaning a different laser is needed for each specific problem.
Recent advances in laser technology mean that laser skin resurfacing – once reserved for the treatment of severe conditions such as acne scarring due to the extensive downtime involved – has become an effective option for many people seeking reduction of lines and wrinkles and uneven skin colour, tone and texture.
Most resurfacing lasers work by removing microscopic quantities of skin and stimulating the production of new collagen. Non-ablative lasers uses wavelengths which do not burn away skin and are suitable for the treatment of melasma, scarring, fine lines and wrinkles and typically do not require any downtime.
Ablative lasers include carbon dioxide (CO2) and Erbium: YAG lasers. These use a process where the upper layers of aged or damaged skin are vaporised by the controlled laser. It is this damage that stimulates the healing and restructuring of the skin, resulting in a more even complexion and a significant reduction in lines and wrinkles.
Carbon dioxide lasers can dramatically reduce wrinkles but downtime and side effects such as redness and peeling are extended, usually taking many weeks to heal. Erbium lasers have a great accuracy with fewer side effects but cannot treat deep wrinkles as successfully.
Fractional laser technology
The advent of fractionated laser, where microscopic columns of skin are treated while surrounding skin is left intact, has made it possible to achieve results comparable results to traditional CO2 laser resurfacing with fewer side effects and profoundly less downtime.
Fractional skin resurfacing can utilise both non-ablative and ablative lasers – the breakthrough difference of this technology is the fractionated delivery system of light.
Fractional laser technologies break up light beams to allow columns of untreated tissue to activate healing mechanisms beneath the skin’s surface, treating skin conditions ranging from scars and birthmarks to wrinkles.
These lasers work by creating microscopic thermal injuries that trigger collagen production, stimulating cell renewal and plumping out the tissues. In other words, the laser works by creating tiny holes, or ‰Û÷dots’, in the skin’s surface, penetrating deep into the dermis. It leaves the skin around each dot intact, enabling the surrounding tissue to heal these microscopic thermal injuries by stimulating the production of new collagen.
The anti-ageing benefits of fractional laser technology include improving evenness of skin tone and texture, reducing pore size and the appearance of lines and wrinkles, and helping to reverse the effects of sun damage. A more mild treatment may take several sessions, while one procedure is usually sufficient for a more aggressive treatment.
Because laser treatments use heat, a mild to moderate burning sensation is experienced during treatment and slight swelling, redness and bronzing afterwards. This can be covered with makeup and normally subsides after a few days, however full healing can take several weeks, depending on the intensity of treatment and the areas targeted.
Results of laser resurfacing vary, depending on the technique and experience of the doctor and the individual patient. Patients should always ask their practitioner how new the laser is and when it was purchased. Recent models are far superior to earlier ones in terms of achieving predictable and precise results.
Intense pulsed light
Intense pulsed light (IPL) in cosmetic therapy uses light wavelengths that safely target either melanin or haemoglobin in the skin. It can be used to fade brown spots and cauterise enlarged or broken capillaries and port wine stain birthmarks. Some laser treatments have been developed specifically to treat rosacea. While it was developed for skin concerns, a side effect of the treatment recognised and harnessed is permanently reducing unwanted hair growth.
Unlike lasers, IPL devices produce a broad spectrum of light in a range of wavelengths. The emitted light is further adjustable through the use of filters, allowing any skin colour to be treated. This versatility allows the characteristics of the light energy to be adjusted according to each patient’s skin type, specific condition and location of the condition.
Another difference is in the area that can be treated in one session. Generally IPL treatment heads are up to eight times larger than the small spot produced by lasers, so treatments are quicker but not as targeted as laser.
In terms of safety, the two types are similar, but with lasers both the practitioner and the patient need to use eye protection. Light from IPL systems may also be harmful to the eyes so protection should be worn for IPL treatments.
While lasers and IPL treat many of the same conditions, IPL is a single technology for a multitude of applications – from unsightly veins and birthmarks to ageing and sun-damaged skin, unwanted hair and rosacea.
During the procedure pulses of intense light are fired at the skin through varying filter which isolate specific wavelengths of light. Various targets (such as haemoglobin in the blood to remove vascular lesions, or melanin to treat hyperpigmentation) are preferentially absorbed, heated and selectively destroyed by certain light wavelengths (called selective photothermolysis) without damaging surrounding tissues.
IPL treatment cannot typically address extensive sun damage and skin discolourations but it can reduce surfaced capillaries, brown spots, as well as help revitalise and even out the overall complexion. Typically four to six treatments are required for optimal results.
The usual downtime with IPL modalities is minimal to none, depending on the intensity of the treatment. However, full recovery can take around two weeks in some cases. Straight after IPL a slight burning sensation can occur for a few hours but there is generally little discomfort. Temporary discolouration can occur for around three to four days after the procedure and will flake off slowly. Short-term side effects include reddening of the skin (erythema), temporary bruising and oedema. Reactions such as scabbing and blistering are possible though rare. It’s important to protect skin from UV light with daily sunscreen application.
Photodynamic therapy
Photodynamic therapy uses a chemical reaction activated by light energy to selectively destroy specific tissues and treat sunspots, certain types of skin cancer, rosacea, acne and sun-damaged skin. A photosensitising medication is applied topically on the skin and a narrow band of (red or blue) light is administered to cause a moderately deep exfoliation and target damaged tissue and sebaceous glands.
When skin is exposed to a light source of an appropriate wavelength, its photosensitiser molecules are activated to produce oxygen intermediates that destroy the targeted cells. Recovery time is around two weeks after each treatment and usually one to three sessions are required.
