J AM ACAD DERMATOL
Table VI. Laser, Light, and Energy
Light and energy
Intense pulsed light
Er, Erbium; KTP, potassium-titanylphosphate; Nd, neodymium; YAG, yttrium-aluminum-garnet.
Other substances are constantly being created or tried for use in augmentation of scars. It is impossible to include each one and address them with the attention they deserve. Only 4 other products will be briefly mentioned. However, others exist that can be researched at the reader’s option (eg, Gore-Tex or SoftFoam that are typically reserved for facial implantation but can used for acne scarring reconstruction). Radiesse contains 25 to 45 mediameter calcium hydroxyapatite microspheres in polysaccharide (carboxymethylcellulose) aqueous gel. It is categorized as ‘‘semi-permanent’’ with earlier claimed durations of 2 to 5 years, but more recent estimates of a year to 16 months. There is little inflammation or side-effect profile and no allergy testing is required. Reviderm Intra consists of 40- to 60-m Sephadex (dextran) beads suspended in bacterial-derived hyaluronic acid. It stimulates inflammation and neocollagenesis. ProFill is a polyoxyethylene and polyoxypropylene polymer forming an injectable gel that must be refrigerated as a liquid until used. Skin testing is not necessary. Fibrel is patient plasma that is mixed with porcine gelatin plus epsilon-aminocaproic acid and lidocaine. It serves as a physical filler and a media for neocollagenesis. This product requires a patient blood draw and may be more painful on injection or lead to a local inflammatory response.
Light, laser, and energy therapy
The concept of selective photothermolysis bases treatment on the wavelengths of various chromophores, notably water, hemoglobin, and melanin. In 1983, Anderson and Parrish75 authored a study outlining selective photothermolysis. They noted that ‘‘selectively brief pulses of selectively absorbed optical radiation can cause selective damage to pigmented structures, cells, and organelles in vivo. Precise aiming is unnecessary in this unique form of radiation injury because inherent optical and thermal properties provide target selectivity.’’ Two key concepts are, first, ‘‘in choosing the laser wavelength for selective photothermolysis is to maximize selective optical absorption in the desired targets’’ and, next, that ‘‘the transition from specific to nonspecific thermal damage occurs as the laser exposure duration (pulse width) equals and then exceeds the thermal relaxation time.’’75 This established principle is used in all of the following laser or wavelengthbased treatments. Again, this is not an all-inclusive discussion and does not cover the nuances of variation between different companies’ products or all of the positives and negatives of a particular device, because that can be researched elsewhere if desired. However, each of the ablative or nonablative methods discussed (Table VI) includes key points with an attempt to include at least one fairly recent reference to its use.
The first category will include those methods of ablative skin resurfacing: carbon-dioxide laser, erbium: yttrium-aluminum-garnet (Er:YAG) laser, and fractionated lasers. The carbon-dioxide laser has a wavelength of 10,600 nm as its target chromophore is extracellular and intracellular water. This treatment is more aggressive and deeper than a chemical peel but remains at a specific depth of 20 to 30 m with thermal damage of 50 to 150 m. It is usually bloodless but still achieves total ablation of the epidermis and a portion of the dermis. In addition to the destructive nature, there may also be stimulation of collagen by the procedure. The usefulness is primarily for hypertrophic scars, boxcar scars (preferably shallow), and, less effectively, keloids. There are some who achieve fairly quick results, visible as soon as 2 weeks, but improvement because of the wound-healing phases continues for at least 18 months. Walia and Alster76 studied 60 patients (50 women, 10 men; age 18-53 years, mean age 38 years; Fitzpatrick I-V) after treatment with the carbondioxide laser. The average improvement was 69% at 1 month, 67% at 6 months (the decrease was attributed to resolution of edema with the temporary revisualization of some lesions), 73% at 12 months, and 75% at 18 months. Neocollagenesis and remodeling were persistent up to the 18-month period of observation. It is not usually necessary to repeat the procedure but the visible recovery time is prolonged, often 1 to 3 months or more. Other side effects could be protracted visible healing, prolonged erythema, eczema, hyperpigmentation or hypopigmentation, milia, acne, cysts, infection, telangiectases, or additional scarring.
Acne Scarring A review and current treatment modalities BACKGROUND and ACNE SCARS ACNE SCARS page 2 ACNE SCAR TREATMENT and MEDICAL MANAGEMENT SURGICAL MANAGEMENT PROCEDURAL MANAGEMENT PROCEDURAL MANAGEMENT page 2 TISSUE AUGMENTATION TISSUE AUGMENTATION page 2 TISSUE AUGMENTATION page 3 TISSUE AUGMENTATION page 4 Light, laser, and energy therapy Light, laser, and energy therapy page 2 Light, laser, and energy therapy page 3 Light, laser, and energy therapy page 4 Conclusion and REFERENCES Manufacturers of brand name drugs mentioned in this article