Which laser levels are appropriate for which procedures?
Laser therapy is a fairly new treatment modality, with the first laser developed in 1960 according to Ronald J. Riegel, co-founder of the American Institute of Medical Laser Applications.
It’s even newer within the United States when compared to other areas of the world, says Riegel. This type of therapy was recognized in Eastern Europe, the Soviet Union, and China by the 1970s, but it didn’t actually appear here until 1977, finally receiving approval from the U.S. Food and Drug Administration in 2002.
The 4 levels of laser therapy
The Laser Institute of America (LIA) further explains that are four basic laser levels, some with sublevels to differentiate them further. The category a laser is placed within is based on factors such as radiation exposure, potential damage to the eye, and whether it is subject to control measures.
These laser levels can be broken down as follows:
- Class 1 lasers. The LIA states that this level of laser is “incapable of producing damaging radiation levels” and is also exempt from control measures. There is a sublevel classification under class 1 (class 1M) that is subject to control measures and includes lasers incapable of doing damage unless a telescope or other optic device is used.
- Class 2 lasers. Lasers falling under this class are not subject to control measures and emit 400 nanometers (which is abbreviated as nm and refers to the wavelength of the laser) to 700 nm, which means that protection is required to keep from damaging the eye. Class 2 laser levels also have a sublevel (class 2M) that is capable of damaging the eye if optic devices are used, and requires control measures.
- Class 3 lasers. Class 3 lasers are separated into two sublevels: 3R and 3B. The Class 3R laser systems are those identified by the LIA as potentially hazardous visually, but adds that “the probability of actual injury is small” unless the eye is focused on the laser. The 3B lasers could be hazardous with direct viewing, so control measures are not required for 3R lasers, but are for 3Bs. Additionally, neither 3R or 3B laser systems are fire or diffuse-reflection hazards.
- Class 4 lasers. This class of lasers are the most intense, which means that control measures are required since they are hazardous to the eyes and skin if a direct beam is used. The LIA indicates that they are also a fire hazard, a diffuse-reflection hazard, and may produce hazardous radiation.
While laser levels are used to classify lasers in a variety of applications ranging from compact disc players to laser pointers and DVD writers, they also provide clues as to the type of healing properties provided when used for medical purposes.
Laser levels and healing
For example, research published in the journal MOJ Orthopedics & Rheumatology indicates that therapeutic lasers that fall under the 3R or 3B classification are commonly called low-level laser therapies (or LLLTs).
These lasers are generally used in 30-second to one-minute intervals and work by inciting biochemical changes on a cellular level, similar to how photosynthesis works in plants. Additionally, the four goals of LLLT are:
- To promote healing and cellular remodeling;
- To reduce edema and inflammation;
- To induce analgesia in the nerves; and
- To reduce tenderness in trigger points.
Some studies have connected LLLT with positive outcomes in cases of chronic pain conditions which afflict approximately 30% of Americans, though the exact mechanisms behind its positive results are not entirely understood. Researchers suggest that this is partially because of the various studies using different dosages and wavelengths, making it difficult to draw clear cause-and-effect conclusions.
Class 4 lasers, on the other hand, are the level of lasers typically used during hospital-based surgical procedures such as laser eye surgery, kidney stone removal, or to shrink tumors. According to the Occupational Safety & Health Administration (OSHA), these more intense lasers “are designed to deliver laser radiation for the purpose of altering biological tissue,” thus providing the desired result.
Medical laser benefits and risks
The Food and Drug Administration adds that medical lasers – those that generally fall in Class 3 or 4 – can provide a number of benefits for patients. Among them are reduced blood loss, less postop discomfort, lower infection risk, and better healing of the wound.
However, there are some risks associated with laser therapy says the FDA, some of which include scarring, changes in skin color, and risk of infection or bleeding. Thus, laser levels need to be considered by health care providers and patients before engaging in laser therapy treatment.