Light Therapy Glossary

If you’re interested in working in a medispa, one of the best things you can do is familiarize yourself with the treatments and the jargon that accompany them. For a look at what’s what in light therapy, you can check out this handy guide put together by Lumiere Light Therapie/Photo Therapeutics Inc.

Ablate – to remove or dissipate by vaporization, melting or erosion, as the removal of abnormal growths from the skin of the body by surgical means, such as a laser or scalpel.

Acne – caused by blocked, inflamed sebaceous (oil) glands and the p. acnes bacteria.  Acne can occur on the face, chest, shoulders and back, and in other areas as well. The types of acne range from mild (Grade 1), to severe (Grade 4). If the inflammation is deeper in the pore, blockages can enlarge to form painful cysts that leave scars or cause craters in the skin, if not properly treated.

Apoptosis (natural cell death) – the last line of defense of the immune system, where cells severely damaged by stress, aging, infection, UV or other aggressors, are selectively killed off, or commit “cell suicide,” so as not to replicate more damaged cells that can cause cancer. 50 to 70 billion cells die naturally each day in the average adult.

Collagen – a high-strength, fibrous protein material found in abundance in skin, bones, tendons, and connective tissue. It is responsible for skin support and elasticity, and its degradation leads to the sagging and wrinkles that accompany aging. There are 28 different types of collagen.

Continuous Light – Light that is emitted in a continuous, constant stream.  This light is the most efficient way to stimulate cell receptors and mitochondria as well as activate photosensitive materials.

Elastin – The body’s structural protein, elastin is found in the skin, arteries, lungs and intestines. It functions in partnership with collagen, with collagen providing rigidity and elastin allowing for stretch and recoiling of tissues.

Fibroblasts – primary cells of the dermis (skin) that produce collagen, elastin and reticular fibers that are extremely important to tissue repair; they also produce other cells to form bone, fat, and smooth muscle cells.

IPL (Intense Pulsed Light) – Pulsed Light is emitted by Intense Pulsed Light sources such as a cosmetic lasers. The light of this “gentle laser,” which is cooler than most CO2 lasers, is transmitted in pulses to reduce thermal damage to the skin and is administered in a series of applications to reduce pain and swelling. IPL generally ablates only 15 to 20% of the skin surface, whereas CO2 Lasers ablate a larger surface area, but both can produce skin inflammation and require healing time following application.

LED (Light emitting diode) – a small semiconductor chip about 1 mm2, in circumference that emits a selective, single wavelength of light when an electrical current is passed through it. The light is cool, focused and does not burn skin.

Mitochondria – the powerhouse of the cell that manufactures and regulates production of ATP (adenosine triphosphate) which powers cellular function and replication.  Contains the photoacceptors within the cell.

Nanometer (nm) – very small unit of measure equal to a billionth of a meter; used to measure wavelengths of light.

PDT (Photodynamic Therapy) – This treatment modality involves administration of a photosensitizing compound to targeted cells, followed by selective irradiation of the treatment area with non-thermal (usually visible) light. The combination of two non-toxic elements, a drug substance and a light source; the light converts naturally occurring tissue oxygen to short-lived, highly toxic singlet oxygen or superoxide with a life of only about 1 microsecond. Used for treating certain cancers and acne.

Phototherapy – a term which includes all types of treatment which use light to induce reactions or changes in the body to benefit a patient; includes the simpler forms of light used to treat jaundiced newborns, or SAD (Seasonal Affective Disorder) as well as more specialized light sources such as LED and Lasers.

Photoacceptors – Part of a cell structure than can induce or regulate a metabolic reaction.  In order to initiate a cellular response to light, exact molecular keys are needed to unlock specific photo-biological processes within the cell; photoacceptors are selective in their ability to absorb a specific narrow band wavelength to produce cell changes.

Photobiomoudulation – biological stimulation produced by certain wavelengths of light at specific intensities and for a specified time period by LED, laser or monochromatic light sources, to aid in tissue regeneration, reduce inflammation, or relieve pain. Cell changes include increased cell permeability, up-regulation and down-regulation of ATP (cell energizer), and does not involve heat, which can damage surrounding cells.

Porphyrins – A group of naturally occurring pigmented photosensitisers that play an important part in various biological processes.  They can be excited by certain selective wavelengths of light to initiate photodynamic therapy.

Singlet Oxygen - a highly toxic, yet short-lived species of free radical that efficiently destroys cells by urging them to shut down naturally (apoptosis).  This process does not evoke a scarring of fibrotic reactions, as in tissue necrosis, where injury takes place and cells are not disposed of naturally. Since singlet oxygen has a very short life (< 1 microsecond) its destructive effects are confined to one cell.

Visible light spectra – wavelengths in the rage of 400 to 700 nm; Ultraviolet: < 400 nm; Infrared: > 700 nm