Non-ablative lasers have lower energy than ablative lasers and cause damage within the dermal layer of the skin without removal of the outer epidermal layers.
The laser heating the dermal layers of skin causes collagen to be produced which helps the appearance of fine lines and wrinkles. Non ablative lasers are useful as they minimise downtime but the results overall are not as good as ablative lasers.
Types of Non-Ablative Lasers
Pulsed Dye: this laser uses a liquid dye (Rhodamine 64). It produces yellow laser which is delivered in short flashes. This is absorbed by the hemoglobin present in the blood and tissues and produces heat damage. This is therefore use to treat vascular lesions like Portwine stains, nevus flemmus, hemangiomas, keloids, hypertrophic scars. It is also used to treat pigmented nevi. Long pulsed dye laser is used to treat fine veins,telangiectasia and blushing.
Pulsed KTP: These lasers operate at a wavelength of 532nm. KTP means Potassium Titanyl-phospate. The laser targets selective irregular spots on the skin, specifically red (haemoglobin) and brown (melanin) areas on the skin. It is especially used to treat the appearance of redness, vessels or brown spots. The laser has a relatively high optical damage threshold (15 J/cm2) and has excellent thermal stability. The KTP Laser operates in the green spectrum and the energy is highly absorbed by oxyheloglobin content such as prostatics tissue.
Nd:Yag: Nd:Yag is a crystal that is used as a lasing medium for solid state lasers. Nd (neodymium) typically replaces a small fraction of the yttrium ions in the host crystal structure of the yttrium aluminium garnet (YAG), since the two ions are of smaller size. It is the neodymium ions which proves the lasting activity of the crystal, in the same fashion as red chromium ion in ruby lasers. These lasers optically pumped using a flashtune or laser diodes. They are a common type of laser. They typically emit light with a wavelength of 1064nm, in the infrared spectrum. There are also transitions near 940nm, 1120nm, 1320nm and 1440nm. They operate in both pulsed and continuous mode. Pulsed Nd:Yag are typically operated in the Q-switching mode: an optical switch is inserted in the laser cavity waiting for a maximum population inversion in the neodymium ions before it opens. The lightwave can then run through the cavity depopulating the excited laser making a maximum population inversion. Nd Yags absorb mostly in the 730nm to 760nm and 790 to 820nm wavelengths. Frequency doubled Nd:Yags are also available at a wavelength at 532nm.
The most common uses of Nd:Yags are: Tattoo removal, treatments for Melasma, freckles, inflammatory acne, nevus of ota, café au lait.
Diode: Diode lasers produce laser beams in the wave length of 800 nm. It is most popularly used for removal of black /brown hair. (white hairs are not targeted by laser beam). Innovative devices with cooling mechanisms give better results with less scarring. Diode lasers have been found to work well on dark skin also. The diode laser is a non-ablative laser so downtime after treatments are minimal. Other treatments for the diode laser include Skin Tightening and Acne treatments but are not as effective as other lasers for these indications.
Erbium Glass: Erbium Glass or Er:Glass has a wave length of 2940 nm. It produces laser in the infrared range. In pulsed mode it is used for treatment of wrinkles, acne scars (resurfacing), precancerous lesions and for ‘laser peels’.
The 1540 erbium glass laser is used for rejuvenation of skin.
Alexandrite: Alexandrite lasers operate at a wavelength of 755mn and are widely used for the treatment of hair removal. Their application is best suited for removal of fine hairs and can remove very light or grey hair when power is increased. They are also available in a Q-switched mode. Other indications for Alexandrite lasers are Pigmented and uneven skin tone, whitening, fine wrinkle reduction, large pores and skin rejuventation.
Ruby: Ruby laser produces red beam in the wavelength of 694 nm. In high energy rapid pulsed mode it is used to remove tattoos, brown pigmented disorders like actinic lentigenes, freckles, nevi and ‘cafe-au-lait’ spots,dilated blue veins,peri orbital pigmentation.
IPL: IPL describes the use of intense pulses of non-coherent light distributed over a range of wavelengths from 500nm to 1200nm. IPL uses short blasts of a polychromatic, high-intensity light to penetrate just below the skin’s surface, damaging either the melanin that makes up brown “age spots” or the blood vessels that create broken capillaries (Spider Veins). IPL also stimulates the production of collagen, which give the skin a more refreshed look. The latest IPL Machines are also useful for hair removal.