The KTP laser is very effective at treating veins. The laser emits a powerful light that is well absorbed by the color in the veins.
As the light is absorbed it is turned into heat and the veins are gone. The flash of light is so short that the heat does not have time to spread into your skin, and because there are no injections or scalpels scarring is most unlikely.
Facial Spider Veins, or Telangiectasia, are one of the most common facial skin conditions for which patients seek treatment. These unsightly dilated blood vessels are seen almost exclusively in patients with fair skin, and are often associated with chronic sun exposure, rosacea, overuse of cortisone creams and certain autoimmune diseases, and occasionally they may be hereditary. In many cases, the exact cause is unknown. Contrary to popular opinion, facial telangiectasia are not associated with alcohol abuse.
Unlike leg veins, which are induced and aggravated by gravity, facial telangiectasia are usually capillaries or small arteries (arterioles) in the papillary dermis, with weakened elastic fibers in their walls which allow them to dilate and become visible, and despite their common name, they are not true "veins". They can be classified according to their appearance as linear, arborizing (branching), spider, or punctate telangiectasia. The linear and arborizing type occur most commonly around the nose, and the spider type are most common on the cheeks.
Background: Before medical lasers were developed, facial telangiectasia were usually treated with pinpoint electrocauterization ("electric needle"). Besides being uncomfortable, cauterization often caused pinpoint scarring and discoloration, especially in the thick, oily facial skin areas where telangiectasia commonly occur. In the late 1970's and early 1980's, the continous wave (CW) CO2 laser was used, although results were little better than with electrocautery. The Argon Laser's blue-green light is effective for superficial vessels, but its shallow penetration and non-specific thermal effect limits its use on deeper vessels and dark skinned patients. In the late 1980's the Pulsed Dye Laser, emitting short pulses of yellow light was developed, and although it's effective, its short pulse duration (less than 1 millisecond) ruptures the telangiectasia, causing purpura, or black and blue marks, which can take up to 2 weeks to resolve. In the 90's the Copper Vapor Laser , Copper Bromide, and Krypton lasers were also used to treat facial telangeictasia. Later, the Frequency Doubled Q-Switched Nd:YAG laser, which is usually used to treat certain tattoo colors, was noted to be effective, but the short Q-Switched pulse also caused vessel rupture with purpura.
In the last few years, the "long pulsed" frequency doubled Nd:YAG laser (KTP Laser) has become the laser of choice for the treatment of facial telangiectasia.
Treatment of Facial Telangiectasia: Like most other lasers, the KTP laser makes use of the principle of selective photothermolysis to coagulate abnormal blood vessels while sparing the surrounding tissue. The KTP laser emits a brilliant green light at 532nm, close to a major absorption peak of hemoglobin in blood. The blood absorbs the laser energy more than the surrounding tissue, and by selecting a pulse width less than the thermal relaxation time of the blood vessel, the blood vessel can be selectively coagulated without causing purpura or damaging the skin.
Hemangiomas and Vascular Malformations: Hemangioma is used as a generic term to describe an abnormal growth or proliferation of blood vessels. More properly, the term hemangioma refers to lesions not present at birth, that appear and proliferate at some time after birth, and usually disappear, or involute. Growths present at birth that remain unchanged or that grow slowly are more properly referred to as a Vascular Malformation.
Hemangiomas occur in about 2-7% of newborns, more commonly in females and multiple births. They present as whitish, flat patches surrounded by dilated blood vessels, but enlarge over the first year of life. Most hemangiomas will begin to regress by age 4, eventually leaving a small, barely visible patch of slightly irregular skin, although incomplete regression is common. In a very few cases, these lesions may enlarge rapidly , become irritated and bleed, and even affect vital structures. Occasionally they may be associated with similar lesions inside the body, especially the larynx and trachea. Most of these lesions require no treatment-more aggressive growths can be treated with oral or injected cortisone, or even with Interferon. Laser treatment of these lesions is controversial. Some authorities recommend early treatment in infancy with the Pulsed Dye or KTP laser, which may limit the growth and encourage early regression of these unsightly lesions. Others reserve treatment for those lesions than have not begun to regress spontaneously after age 3 or 4. In either case multiple treatments are necessary.
Port Wine Stains are a type of vascular malformation present in about 1% of newborns, most commonly on the face and neck, and visible at birth as a pinkish or blushed area, which often occur in the distribution of an underlying nerve. A plexus of very small blood vessels is present in the papillary dermis, and with time, the vessels become progressively more dilated and eventually assume a pebbled or nodular appearance. Optimal treatment is with the Pulsed Dye Laser (PDL) beginning in infancy-treatment becomes more problematic as the lesion gets darker and thicker. Treatments are performed about 2 months apart, using topical anesthetic cream, often with the infant in a parent's arms. Mature lesions can be photocoagulated with the Argon or KTP laser. Multiple treatments are necessary in either case, and complete removal of the growth is not possible in every case.
Cherry Hemangioma (angioma) is
the most common of all the vascular malformations. These smooth red-to-purple 
papules
will rarely grow larger than about 1/4 inch, and occur mostly on the trunk in
persons over 30. Their exact cause is unknown, but they can be treated with a
variety of methods, including the CO2, Argon, or KTP lasers. Occasionally, they
may mistaken for nodular melanoma-note the large, dark cherry hemangioma on the
right.
Venous
Lake: Venous Lakes are most common
on sun-exposed areas in older individuals, especially on the vermilion of the
lip and on the ears. These smooth, easily compressible lesions are simply a
dilated or "varicose" vein. Because of their deep purple, almost black
color, they may be mistaken by patients for melanoma, and bleeding following
trauma or irritation may occur. Venous lakes are easily treated by needle point
electrocautery, or with the CO2, argon, or KTP lasers.
Unilateral Telangiectasia Syndrome can either be congenital or acquired; the acquired form often begins with increasing blood levels of estrogen, such as with oral contraceptives or pregnancy. Usually, the telangiectasia will occur on the face or neck, and follows the distribution of an underlying nerve. These lesions can be treated with the Pulsed Dye or KTP lasers.
Hereditary Hemorrhagic Telangiectasia: Also known as Rendu-Weber-Osler Disease, this is an inherited malformation of blood vessels. Small, flat or punctate telangiectasias appear in childhood and gradually become more visible in adulthood, mostly on the lips, tongue, nasal mucosa, and forearms, although any area of the body may be involved. These telangiectasias are delicate and can bleed easily, which at times may be severe and require transfusion. Nosebleeds are especially common and severe in these patients. Treatment is with electrocautery, argon, KTP or CO2 lasers. Persistent nosebleeds may be treated with skin grafts to affected areas inside the nose.