| Glossary |
| A |
| Absorption |
| The act of tissue taking up laser energy, causing a reaction within the tissue |
| |
| Absorption peak |
| Place on an absorption curve where light absorption by a chromophore in tissue is significant |
| |
| Acne |
| A disorder of the skin caused by inflammation of sebaceous glands and hair follicles |
| |
| Aiming beam |
| A second low power coaxial laser which provides a defined visible target area. Used with infrared or other invisible wavelengths |
| |
| Anatomical parts of hair |
| Follicle, bulb, bulge, vascular, supply (matrix) and hair shaft |
| |
| Angioma (Cherry, spider) |
| Capillary hemangiomas. Flat or raised tumor composed of a mass of tiny blood vessels, bright red in color, usually 2-5mm in size |
| |
| ANSI |
| American National Standards Institute - voluntary nationally recognized group establishing standards for equipment use. The ANSI Z136.3 standard pertains to the use of medical lasers |
| |
| Articulated arm |
| A laser delivery system that utilizes a jointed arm and mirrors |
| |
| Atrophic |
| A wasting, progressive degeneration and loss of function of any part of the body |
| |
| B |
| Becker's nevus |
| Similar to but less common than Café-au-lait macules, and typically larger (5-40cm). Also have course hair present within the patch, and usually located in the shoulder area |
| |
| C |
| Café au lait |
| Light tan to light brown macules often apparent at birth, epidermal in depth, ranging from 1cm -20cm in diameter |
| |
| Cavitation |
| Formation of a cavity or erosion |
| |
| Chloasma/Melasma |
| Light to medium brown discoloration of the face commonly associated with pregnancy; called "mask of pregnancy" |
| |
| Chromophore |
| A target that absorbs light. |
| |
| Class of lasers |
| Broad classification of lasers based on the ability to cause injury, Class I-IV, Class IV devices are the most dangerous / powerful |
| |
| Coherent |
| All the waves of the laser beam are lined up in phase with each other in time and space |
| |
| Collagen |
| An insoluble fibrous protein that is the chief constituent of the fibrils of connective tissue (as in skin and tendons) and of the organic substance of bones |
| |
| Collimated |
| All the waves of the laser beam are parallel to each other and don't converge or diverge |
| |
| Congenital nevi |
| Nevi which are present at birth |
| |
| Congenital vascular malformation |
| General term for vascular lesion present at birth, such as Port Wine Stains, hemangiomas, and venous malformations |
| |
| Corneal Shield |
| Protective covering which is inserted under the eyelid and placed directly onto the surface of the eye. |
| |
| Cryogen |
| A substance used to induce a low temperature in an object |
| |
| D |
| DCD |
| Dynamic Cooling Device which sprays a cryogen cooling agent on the skin prior to the laser pulse being fired or during a laser procedure |
| |
| Delivery system |
| Components used to apply laser energy to a patient, ie. Articulating arm, fiber, handpiece |
| |
| Dermatitis |
| Inflammation of the skin |
| |
| Dermis |
| The deeper, thicker layer of skin beneath the epidermis which contains blood vessels, nerves and hair |
| |
| Distance gauge |
| A spacer between the handpiece lens and the treatment site, which if placed in contact with the skin, ensures that the beam is the proper focal distance |
| |
| E |
| Ectatic |
| Dilatation of a hollow organ or tubular structure such as an enlarged blood vessel |
| |
| Edema |
| Swelling due to collection of fluid in interstitial space |
| |
| EMLA |
| Topical anesthetic cream –containing 2.5%lidocaine and 2.5%prilocaine |
| |
| Energy density |
| The amount of energy contained within a given spot size - see Joules |
| |
| Epidermis |
| The outermost thin layer of skin |
| |
| Epilation |
| The removal of hair |
| |
| Erythema |
| Redness of the skin |
| |
| F |
| Facial Telangiectasia |
| Dilation of a group of capillaries on the face, also called spider veins |
| |
| Fiber |
| A quartz or glass filament used as a delivery system for laser energy |
| |
| Fitzpatrick skin types |
| Classification system of skin types based on tanning characteristics and melanin content (Types 1-6). Type 1 being fair skin, easily burned - to type 6 never burn very dark skin |
| |
| Flashlamp-excited |
| Utilizing high intensity flashlamps to excite a lasing medium to produce laser energy |
| |
| Fluence |
| The amount of energy delivered to the tissue calculated by Watts x Time divided by the spot size in cm2 |
| |
| Focal length |
| Distance between the lens and the focal point, or the distance from the lens which provides the proper beam size |
| |
| Focusing lens |
| Lens used to focus the laser beam to a specific spot size |
| |
| G |
| Gating or shuttered pulse |
| Method of using a mechanical shutter to produce a "pulsed" effect in a laser beam |
| |
| H |
| Hair anatomy |
| Folicle, bulb, bulge, vascular supply, matrix, shaft |
| |
| Hair growth cycle |
| The growth phases of hair |
| |
| Hemangioma |
| Benign tumor made up of blood vessels |
| |
| Hirsuitism |
| Excessive hair growth on cheek, chin, lip or chest; especially in women due to an increase in androgenic production |
| |
| Hyperpigmentation |
| Increased pigmentation in tissue or skin |
| |
| Hypertrophic |
| Enlargement of an organ or part due to the increased size of the cells composing it. |
| |
| Hypopigmentation |
| Decreased pigmentation in tissue or skin |
| |
| I |
| Incoherent light |
| White light, many wavelengths present, i.e. does not have the properties of a laser |
| |
| Inflammation/inflammatory response |
| Tissue reaction to irritation, infection, or injury marked by localized warmth, swelling, redness, and pain |
| |
| Intraoperative |
| Meaning "during" the surgical procedure |
| |
| J |
| Joule (J /(cm2) |
| A measurement of energy density within a given spot size |
| |
| K |
| Keloid |
| A nodular mass of scar tissue which has grown well outside the original boundaries of a scar |
| |
| L |
| LASER |
| Light Amplification by Stimulated Emission of Radiation |
| |
| Laser parameters |
| Characteristics of a laser beam, or the settings used on the laser device, which may include |
| |
| Lentigines |
| Small tan to brown epidermal lesions or macules usually arising from sun exposure which increase in number as a person ages. |
| |
| M |
| Medium |
| Substance which produces laser energy |
| |
| Melanin |
| Pigment which is produced by melanocytes in the skin |
| |
| Melanocytes |
| Pigment producing cells in the skin |
| |
| Melanocytic nevi |
| Medium to dark brown macules which are dermal in depth and tend to occur on the trunk and extremities. Can be from .5cm to several centimeters in diameter, and have a relative higher risk of becoming malignant. |
| |
| Melanosomes |
| Melanin containing organs within the melanocytes |
| |
| Microseconds |
| 10-6 seconds, or .000001 seconds |
| |
| Milliseconds |
| 10-4 seconds or 1/1000th of a second |
| |
| Monochromatic |
| Meaning one color; one specific wavelength of light. |
| |
| Monte Carlo Simulation |
| Computer optical simulation of photons moving through tissue based on optical properties |
| |
| N |
| Nanometer |
| 10-9 meters, or .000000001 meters |
| |
| Nanoseconds |
| 10-9 seconds, or .000000001 seconds |
| |
| Nevus of Ota |
| Blue gray lesion on the face most commonly seen in Asian populations. Dermal in depth, and usually seen around the eye, temple and cheek area. |
| |
| Non-ionizing/ionizing radiation |
| Non-ionizing forms of radiation include |
| |
| O |
| Optical density |
| Resistance of a substance to light energy |
| |
| OSHA |
| Occupational Safety and Health Administration |
| |
| P |
| Perifollicular edema |
| Swelling due to collection of fluid in the interstitial space in the area around the depression in the skin from which the hair emerges. Positive sign of proper energy delivered for hair removal |
| |
| Photo-ablation |
| The act of removing tissue by vaporization with light |
| |
| Photo-acoustic |
| Light that generates an acoustic shock wave effect in tissue |
| |
| Photo-chemical |
| Act of light causing or initiating a chemical reaction |
| |
| Photo-thermal |
| Action of turning light energy into heat. |
| |
| Photons/ molecules of light |
| Light energy given off by an excited atom |
| |
| Photosensitivity |
| Increased sensitivity to light |
| |
| Pigmented Lesions |
| Congenital or acquired brown to black skin lesions |
| |
| Poikiloderma of Civatte |
| Hyperpigmentation and telangiectasias of the sides of the neck and chest associated with chronic sun exposure |
| |
| Port Wine Stain (PWS) |
| A pink to purple macular congenital vascular malformation of dermal vessels. Also called nevus flammeus. |
| |
| Post-inflammatory pigmentation |
| Area(s) of darkening or increased pigment in a laser treated area after treatment. |
| |
| Postoperative |
| Pertaining to after a surgical procedure. |
| |
| Preoperative |
| Pertaining to prior to a surgical procedure |
| |
| Protons, neutrons, electrons |
| Basic components or building blocks of atoms |
| |
| Pruritis |
| Itching |
| |
| Pseudofolliculitus Barbae (PFB) |
| Beard bumps or razor bumps |
| |
| Psoriasis |
| A common chronic skin disease characterized by varying sized reddish patches with white/silver scaly appearance. Occurs mostly on the elbows, knees, scalp, and trunk. |
| |
| Pulse duration/length |
| The length of time a laser pulse lasts, usually in nanoseconds, microseconds, or milliseconds. |
| |
| Pulse repetition rate |
| The rate at which a laser fires pulses, usually in pulses per second or Hertz (Hz) |
| |
| Pulsed dye |
| Laser that produces light from an organic dye in solution |
| |
| Pulsed vs. CW lasers |
| Lasers that generate short bursts or pulses of light vs. lasers that emit a continuous beam of light |
| |
| Purpura |
| A purplish or blue/black discoloration of the skin after laser treatment, a bruise. |
| |
| Q |
| Q-switching |
| The use of a pockel cell to generate very high peak power for a very short period of time, usually in the nanosecond range |
| |
| R |
| Reflection |
| The act of light bouncing off of a surface after striking it |
| |
| Resonator |
| Laser head or laser cavity, or laser tube. The place where the lasing medium is housed and the laser energy is produced |
| |
| Rhytides |
| Wrinkles, lines or creases that appear most notably on the face as a person ages. Can increase with sun damage and smoking |
| |
| Rosacea |
| Dilation of capillaries in the cheeks, nose, forehead and chin; adult onset acne and blushing or flushing induced by a variety of triggers |
| |
| S |
| Scars |
| Fibrous tissue formed during the healing of a wound |
| |
| Scattering |
| Process in which a light beam is split apart in many different directions after striking a object or tissue |
| |
| Sclerotherapy |
| The injection of a chemical into a vein to obliterate the vessel |
| |
| Sebaceous Hyperplasia |
| Enlargement of sebaceous glands. |
| |
| Seborrheic Keratosis |
| A benign pigmented lesion which is raised, tan, brown or black colored, usually on the face, back and chest of older adults; may have a greasy wart-like appearance |
| |
| Selective Photothermolysis |
| Theory on which lasers are designed which states that one chooses a laser wavelength that a target absorbs strongly, while surrounding structures do not, and having an exposure time less than the thermal relaxation time of the target |
| |
| Selectivity |
| Absorption by a particular target, without effecting surrounding structures |
| |
| Skin Rejuvenation |
| Erasing fine lines and wrinkles through the use of laser or light-based treatments |
| |
| Spider Hemangioma |
| Arterial spider. A dilated arteriole of the skin with radiating capillary branches. |
| |
| Spot size |
| Usually denotes the size of the treatment beam, can be expressed in circular diameter, or in the case of scanner handpieces, other geometric shapes. |
| |
| Stimulated emission |
| Process by which a molecule emits two photons of light after absorbing one |
| |
| T |
| Target |
| Tissue or substance a laser beam is directed at |
| |
| Telangiectasia |
| Dilation of a group of capillaries, also called spider veins |
| |
| Thermal injury |
| Damage to tissue from a heat source or photo-thermal reaction |
| |
| Topical anesthesia |
| Anesthetic applied to the surface of the skin, usually a cream, liquid, or gel. |
| |
| Transient / Transitory |
| Temporary |
| |
| Transmission |
| The passage of energy through a medium |
| |
| TRT |
| Thermal Relaxation Time - the time a target takes to release ½ the heat it had gained after being heated |
| |
| U |
| Ulceration |
| A depressed or eroded area in the skin |
| |
| V |
| Vascular Lesions |
| Vascular tissue exhibiting altoreal pathology. |
| |
| Venous Lake |
| A superficial vein-like malformation usually located on the lips or ears. It is soft, compressible, flat or slightly elevated, bluish/red. |
| |
| W |
| Warts |
| A small horny outgrowth on the skin, usually of viral origin, also called verucca |
| |
| Wavelength |
| The distance between two consecutive peaks on a wave of light. Usually measured on micrometers or nanometers. Also determines the color of the light. |
| |
| Wheal |
| Round or ridge-like transitory swelling on skin. |
| |
| |
|
