The first lasers used to treat skin conditions occurred over 40 years ago. Argon and carbon dioxide (CO2) lasers were commonly used to treat benign vascular birthmarks such as port-wine stains and hemangiomas. Although these birthmarks could be effectively lightened, a side effect was the unacceptably high rate of scar formation. In the last 20 years major advances in laser technology has revolutionized their use in the treatment of many skin conditions and congenital defects, including vascular and pigmented lesions, and the removal of tattoos, scars and wrinkles. Nowadays there is a wide spectrum of laser and light technologies available for skin resurfacing and rejuvenation.
Properties of Laser light
- Laser’ is an acronym: light amplification by the stimulated emission of radiation.
- Lasers are sources of high intensity light with the following properties, Monochromatic, i.e., the light is of a single wavelength, Coherent, i.e., the light beam waves are in phase, Collimated, i.e., the light beams travel in parallel
- Laser light can be accurately focused into small spots with very high energy.
- The light is produced within an optical cavity containing a medium, which may be a gas (e.g., argon, krypton, carbon dioxide), liquid (e.g., dye) or solid (e.g., ruby, neodymium:yttrium-aluminium-garnet, alexandrite). The process involves excitation of the molecules of the laser medium, which results in the release of a photon of light as it returns to a stable state. Each medium produces a specific wavelength of light, which may be within the visible spectrum (violet 400 through to red 700nm) or infrared spectrum (more than 700 nm).
- Vascular skin lesions contain oxygenated hemoglobin, which strongly absorbs visible light at 418, 542 and 577 nm, whereas pigmented skin lesions contain melanin, which has a broad range of absorption in the visible and infrared wavebands. Infrared lasers are broadly destructive because they are absorbed by water in and between skin cells (these are composed of 70-90% water).
- The aim is to destroy the target cells and not to harm the surrounding tissue. Short pulses reduce the amount that the damaged cells heat up, thereby reducing thermal injury that could result in scarring. Automated scanners aim to reduce the chance of overlapping treatment areas.
Pulsed Dye Laser
- This Laser emit high-energy laser light in ultrashort pulse durations with relatively long intervening time periods between each pulse.
- Active wavelength is 585-595 nm.
- Lasers have been used successfully to treat a variety of vascular lesions including superficial vascular malformations (port-wine stains), facial telangiectases, hemangiomas, pyogenic granulomas, Kaposi sarcoma and poikiloderma of Civatte.
- More recently PDL has been used to improve hypertrophic scars and keloids. This may require multiple treatment sessions or the simultaneous use of intralesional injections to gain good results. The PDL has been reported to reduce the redness as well as improving texture and pliability of the scar.
- Lasers are sometimes used to remove viral warts destruction of the dermal blood vessels (PDL)
- Q Switched neodymium (Nd): yttrium-aluminum-garnet (YAG).
- Active wavelength is 1064 nm
- Laser systems can successfully lighten or eradicate a variety of pigmented lesions.
- Pigmented lesions that are treatable include freckles and birthmarks, common nevi
- Tatttoo pigment can be removed without causing much damage to the surrounding skin. The altered pigment is then removed from the skin by scavenging white blood cells, tissue macrophages. Only effective for black tattoos. We do not remove tattoos at our office.
- Can remove excessive and cosmetically disabling hair
Adverse effects of Lasers
Laser treatments are basically burns, so it is not surprising that sometimes the following effects may occur:
- Temporary pain, redness, bruising, blistering and/or crusting
- Infection including reactivation of herpes simplex
- Pigment changes (brown and white marks), which may be permanent
- Scarring, which is luckily rare