KTP laser treatment
- Categoria: General
What is a laser?
The term LASER stands for light amplification by stimulated emission of radiation. Lasers produce an intense beam of light of a particular color and wavelength that can vary in intensity and pulse duration.
Lasers can be used for the treatment of various dermatological conditions depending on the wavelength, pulse characteristics and fluence (energy output) of the laser.
A variety of lasers are available; they are differentiated by the medium that produces the laser beam and the wavelength generated.
What is a KTP laser?
A KTP laser is a solid-state laser that uses a potassium phosphate titanate (KTP) crystal as its frequency doubling device. The KTP crystal is trapped by a beam generated by a neodymium:yttrium aluminum garnet (Nd:YAG) laser. This is directed through the KTP crystal to produce a beam in the visible green spectrum with a wavelength of 532 nm.
How does a KTP laser work?
- The KTP laser works on the principle of selective. photothermolysis.
- The selected wavelength of laser light is highly absorbed by the target structure (called chromophore) and less absorbed by the surrounding tissue.
- The skin chromophores targeted by the KTP laser are melanin, oxyhemoglobin and red tattoo pigment.
- The pulse duration of the laser energy is shorter than the thermal relaxation time of the target structure (the time it takes for the target to cool to 50% of its maximum temperature after irradiation).
- This ensures that the impact of the thermal energy is limited to the target structure and does not affect the surrounding tissue. Modern KTP lasers also have integrated cooling systems to help protect the epidermis, particularly when doing vascular work.
- When KTP laser light hits the skin, it is reflected, transmitted or absorbed.
- The absorbed light energy is converted into thermal energy (heat) by the intended targets (chromophores), thus killing the target cells.
- Complications occur when energy destined for the target chromophore is diffused and absorbed non-selectively by surrounding tissues and structures. Because melanin is the target of this wavelength, the KTP laser is rarely used on darker skin.
- The effects of the KTP laser on the skin can be modified by altering the pulse width and the degree of cooling. In the case of tattoo pigment, the pulse width is reduced to nanoseconds (Q-Switched KTP) and the clinical effect is photomechanical / acoustic. Picosecond lasers may be more effective for pigment fragmentation, but with very short pulse widths, the creation of a plasma veil is a limiting factor.
What is the KTP laser used for?
The following skin disorders can be treated with KTP lasers using an FDA-approved machine, such as The Excel V® (Cutera). The Revlite SI (ConBio) is a Q-Switched KTP laser. Both lasers also have a 1064 nm modulus.
Cutaneous vascular lesions
- The KTP laser is useful in the treatment of some superficial port wine stains (vascular malformation) and a variety of acquired cutaneous vascular lesions, including telangiectasia, cherry angiomas and poikiloderma of Civatte.
- The light energy emitted by the Kd pumped Nd:YAG laser is absorbed mainly by the oxyhemoglobin contained within blood vessels, thus minimizing thermal damage to other structures.
- Laser treatment parameters are based on several factors, including lesion location, lesion morphology and skin phototype of the patient.
- Lower energy densities are needed for anatomical locations with a higher risk of scarring, such as the anterior chest, neck and periorbital area. Skin cooling is essential.
- Only patients with Fitzpatrick skin types I to III are eligible.
- Successful treatment of Civatte’s poikiloderma can be achieved with several treatment sessions. The KTP laser is especially suitable for facial treatment. telangiectasia.
Pigmented and non-vascular skin lesions
- KTP lasers can be effective for freckles, superficial dyspigmentation (e.g. epidermal melasma) and lentigines.
- In the removal of pigmentation, the energy of the KTP laser light is selectively absorbed by the melanin that causes the pigmentation. Skin cooling is reduced, resulting in a photo-thermal melanin lesion.
Rosacea
- KTP lasers can be effective in erythematotelangiectatic rosacea.
What does the laser procedure consist of?
The patient should wear eye protection, consisting of an opaque covering or goggles, during the entire treatment.
- Treatment with the KTP laser consists of placing a handpiece against the surface of the skin and activating the laser. Many patients describe each pulse as feeling like the snap of a rubber band against the skin.
- Current anesthetic or forced air cooling may be applied to the area, but is not necessary if a cooling system is in place.
- Immediately after treatment, a cold pack can be applied to soothe the treated area.
- Care should be taken in the first few days after treatment to avoid scrubbing the area and/or the use of abrasive skin cleansers.
- After treatment, patients should protect the area from sun exposure to reduce the risk of post-inflammatory pigmentation.