Intense pulsed light

Intense pulsed light (IPL) is a technology used by cosmetic and medical practitioners to perform various skin treatments for aesthetic and therapeutic purposes, including hair removal, photorejuvenation (e.g. the treatment of skin pigmentation, sun damage, and thread veins) as well as to alleviate dermatologic diseases such as acne. IPL is increasingly used in optometry and ophthalmology as well, to treat evaporative dry eye disease due to meibomian gland dysfunction. Intense pulsed light (IPL) is a technology used by cosmetic and medical practitioners to perform various skin treatments for aesthetic and therapeutic purposes, including hair removal, photorejuvenation (e.g. the treatment of skin pigmentation, sun damage, and thread veins) as well as to alleviate dermatologic diseases such as acne. IPL is increasingly used in optometry and ophthalmology as well, to treat evaporative dry eye disease due to meibomian gland dysfunction. The technology uses a high-powered, hand-held, computer-controlled flashgun to deliver an intense, visible, broad-spectrum pulse of light, generally in the visible spectral range of 400 to 1200 nm. Various cutoff filters are commonly used to selectively filter out shorter wavelengths, especially potentially damaging ultra violet light. The resulting light has a spectral range that targets specific structures and chromophores (e.g. melanin in hair, or oxyhemoglobin in blood vessels) that are heated to destruction and reabsorbed by the body. IPL shares some similarities with laser treatments, in that they both use light to heat and destroy their targets. But unlike lasers that use a single wavelength (color) of light which typically matches only one chromophore and hence only treats one condition, IPL uses a broad spectrum that when used with interchangeable filters, allows it to be used against several conditions. This can be achieved when the IPL technician selects the appropriate filter that matches a specific chromophore. Intense pulsed light is the use of intense pulses of non-coherent light over a range of wavelengths from 500 nm to 1200 nm. Xenon flashlamps produce high output bursts of broad spectrum. Cooling is used to protect the skin in contact with the device. Regulations governing IPL vary by jurisdiction. 'Intense Pulsed Light' is not a registered trademark. A distinction is sometimes made between beauty-grade and medical-grade machines, mainly to get around regulations. Under the CE marking system no such distinction exists. The first FDA approval of IPL was for telangiectasias in 1995. Use quickly spread to a variety of medical and cosmetic settings. Treatment is generally safe and effective, but complications can occur such as hyperpigmentation. The polychromatic light can reach multiple chromophores in human skin: mainly hemoglobin, water, and melanin. This results in selective photothermolysis of the target, which can be blood vessels, pigmented cells, or hair follicles. IPL can reduce hair growth, most effectively in darker, coarser hair. There are many names and devices for pulsed light treatments such as E-Light, ELOS, and M-Light. Laser hair reduction is different and uses coherent, monochromatic laser light. IPL is NOT a laser. Broad-spectrum light is applied to the surface of the skin, targeting melanin. This light travels through the skin until it strikes the hair shafts or the bulb (root). The bulb is usually where the highest concentration of melanin is located. As the light is absorbed, the bulb and most of the hair shaft are heated, destroying the hair-producing papilla. It is also claimed that heat conversion occurs directly in the darker capillaries that bring blood to the follicle. At any one time, not all hair follicles are ‘active’, and only active hair follicles can be affected by the treatment. ‘Inactive’ hair follicles can be treated as they become ‘active’ over time. For IPL treatments, an average of 8–10 treatments are required to remove most visible hair. No common treatment protocol exists and it depends on the equipment used and patient skin type. The area to be treated should be clean shaven and free of sunburn. Treatment sessions are usually 4 to 6 weeks apart. Treatments are often given in doctors' offices and so-called 'medspas' by trained practitioners. Contrary to what is often claimed, photoepilation is not a permanent hair removal method but a permanent hair reduction method. Although IPL treatments will permanently reduce the total number of body hairs, they will not result in a permanent removal of all hair. This distinction is only relevant in the USA because of FDA wording.