Definition & Overview
Nd:YAG, or neodymium-doped yttrium aluminum garnet, is one of the more advanced types of laser technology now commonly used for the treatment of a wide range of skin and eye disorders. It is marketed under different brand names, including Cutera, RevLite Q-Switched, and Fotona, among others. Each machine is uniquely designed to treat specific problems.
Light amplification by stimulated emission of radiation or laser, is a widely used medical technology that uses the wavelength of high-energy light to penetrate the deeper layers of the skin without damaging its surface, destroying diseased cells by heating them in the process.
Who Should Undergo and Expected Results
Nd:YAG laser treatment can be recommended for patients who require:
- Treatment for skin disorders
- Treatment for certain eye disorders
- Permanent hair removal
- Tattoo removal
- Treatment for certain nail disorders
Nd:YAG treatments are widely used in the field of dermatology for the management of a wide range of skin conditions, including:
- Spider, varicose, and thread veins on the face and legs
- Vascular birthmarks or capillary vascular malformations
- Facial veins
- Haemangiomas or vascular tumours in the face and surrounding the mouth
- Brown age spots
- Mongolian spots
Aside from removing unwanted spots and vascular abnormalities, Nd:YAG can also improve the overall appearance of the skin by reducing wrinkles and treating some inflammatory skin diseases, such as hidradenitis suppurative.
Permanent Hair Removal
The Nd:YAG technology is also a highly effective permanent hair removal solution that be can be safely used on the face, neck, back, chest, legs, underarms, and the bikini area. It works better on patients with dark brown or black hair with light-coloured skin when compared to those with light-coloured or blonde hair with tanned or dark skin.
The Q-switched system, a specific type of Nd:YAG laser system, removes certain tattoos such as those with blue, black, and grey colours. However, outcomes may differ depending on the depth of the tattoo’s pigment.
How is the Procedure Performed?
An Nd:YAG laser treatment requires the use of a special opaque eye cover or goggles to protect the patient's eyes all throughout unless the procedure is meant to treat an eye condition. A special hand piece is then pressed against the skin of the targeted area and activated to emit light pulses. While some patients find it tolerable, others require local anaesthetics.
The level of laser light pulses released by Nd:YAG machines are controlled based on the type of treatment being performed.
For the treatment of vascular skin disorders or discolourations, the procedure specifically targets the haemoglobin, or the red pigment in the cells, as well as the melanin.
For the treatment of vascular conditions affecting sensitive areas such as the face, the ideal pulse is a 50-millisecond pulse duration, with an output energy of 150 to 250 J/cm2. The patient may require 1 to 3 sessions for small red vessels, but may need more if the treatment area is bigger.
When used for hair removal, the laser light pulses damage the hair follicles causing the hair to fall out and preventing them from growing back. For this purpose, longer-pulse Nd:YAG laser systems such as the 1064-nm system, are deemed safer and more effective compared to the nano-second or Q-Switched systems. Typically, 2 to 20 millisecond pulses are used with an output energy of 10 to 40 J/cm2. As skin surface cooling is necessary for this procedure, most hair removal laser systems come with a built-in cooling device. Patients with light skin usually need 2 to 6 treatments with an interval of 4 to 6 weeks in between, whereas patients with darker skin may require more sessions to achieve the desired results.
For tattoo removal, the laser pulses work by selectively destroying the ink molecules, which are then absorbed by macrophages before they are removed from the body. For this purpose, the typical treatment setting is 10-nanosecond pulse durations with a 300-500 Mj output energy. Patients may require anywhere between 5 and 20 sessions with an interval of at least 7 weeks in between depending on the colour and depth of the tattoo.
For the treatment of onychomycosis (nail disorder), there are currently two approved laser devices namely PinPointe Footlaser by Cynosure and the Cutera GenesisPlus by Cutera. Both of them use pumped short-pulse Nd:YAG 1064 nm lasers emitted at 100-3000 microsecond pulses with an energy output of 25.5 J/cm2 for every 1mm of skin. The treatment requires 4 sessions with a 1-month interval in between.
Following an Nd:YAG treatment, an ice pack is applied to the treated area to soothe it. To prevent accidental abrasion, the patient may be given a bandage or patch, especially if the treatment involves some sensitive areas.
Possible Risks and Complications
It is normal for patients to experience some redness, itching, blistering, and swelling in the treated area following the procedure but these resolve on their own without treatment after a couple of days. Aside from these, some complications may also occur. These include:
- Leukoderma - When performed on tanned or dark-skinned patients, there is a risk that white patches will appear on the skin as the laser energy destroys the melanin.
- Post-inflammatory pigmentation
- Hyperpigmentation, or dark patches of skin
- Hypopigmentation, or pale patches of skin
- Bacterial infection, which can be prevented with the use of post-treatment antibiotics
- Laser injuries to the macula, when used as a treatment for eye conditions
Generally, Nd:YAG laser treatments are safer for patients with light skin, but should be used with caution in patients with darker skin.
Goel A. “Clinical applications of Q-switched Nd:YAG laser.” Indian Journal of Dermatology, Venereology and Leprology. http://www.ijdvl.com/article.asp?issn=0378-6323;year=2008;volume=74;issue=6;spage=682;epage=686;aulast=Goel
Nosrati N., Hunter L., Kelly E. “Efficacy of Nd:YAG laser for the treatment of hidradenitis suppurativa.” Journal of Cosmetics, Dermatological Sciences and Applications. http://www.scirp.org/journal/JCDSA/