PEER-REVIEW | HAND REJUVENATION |
Figure 2 (A) Before and (B) after treatment with a Ruby laser
overall improvement of photodamage13 . . Lentigines,
telangiectasias and epidermal pigment have been successfully treated with IPL26, 27
The global improvement of dyspigmentation and
vascularity seen with IPL (515–1200 nm) is a result of the fact that the device targets both melanin (400–755 nm) and haemoglobin (580 nm)28
. Furthermore,
histologic neocollagenesis, as well as an increase in extracellular matrix proteins, can be seen 6 months after treatment19, 29
(ALA) prior to an IPL treatment has shown greater pigmentary and vascular improvement, as well as a more pronounced improvement of fine rhytides following two monthly treatments30, 31
. Cut-off filters are used in IPL therapy so that treatment
parameters, different targets and depth of desired penetration, can be adjusted based on the patient’s skin type2, 28
. In 2011, Sasaya et al32 treated solar lentigines on
the dorsal hands with a 500–1200 nm non-coherent, filtered broadband pulsed flash lamp. They demonstrated a moderate to marked improvement of solar lentigines in 62% of patients and a patient satisfaction survey revealed that 65% of patients were satisfied to very satisfied with the results. The group used a 515 nm filter for shallower penetration into the dermis and higher absorption of melanin32
.
Light-emitting diode therapy Light emitting diodes (LEDs) encompass another category of non-thermal light therapy that has no reported side-effects. It has been shown to accelerate wound healing after thermal-based rejuvenation treatments with the activation of fibroblasts, as well as showing anti-inflammatory properties33–41
. LED
treatment can enhance the efficacy of photodynamic therapy owing to multiple wavelengths and a large, uniform beam profile, as well as reduce pain associated with the procedure39, 40
.
Improvement of photodamaged and aged skin can be seen with a variety of narrow-band LEDs that stimulate natural intracellular photobiochemical reactions. Additionally, non-thermal photobiological processes are
28 ❚ October 2013 |
prime-journal.com . The addition of 5-amminolevulinic acid responsible for accelerating wound repair38, 42–46 . Multiple
clinical trials using a 590 nm wavelength LED to treat photoaged skin were shown to effectively stimulate collagen synthesis, as well as reduce elastosis, erythema and pigmentation in 60–90% of patients35, 38
.
Radiofrequency therapy RF devices were developed in order to increase penetration depth and cause collagen shrinkage with skin tightening47
. Traditional lasers create heat by
targeting selective chromophores, while RF technology produces an electric current that generates heat through resistance in the dermis and subcutaneous tissue48–50
.
The tissue is heated to a temperature of 65–75°C, the critical temperature that causes denaturation and contraction of collagen and consequently, tissue tightening48, 51, 52
. The energy produced by RF develops a
heat that is regulated according to the tissue depth, from the superficial dermis down to the muscle border. Tissues with higher impedance, such as adipose tissue, will produce a greater heat and therefore a greater thermal effect53
. Based on the
principles of selective photothermolysis, the sequential exposure of these wavelengths on target tissue chromophores results in selective thermolipolysis and thermodenaturation of collagen fibres, causing enhanced skin retraction and contraction54
. With the
use of RF technology, shorter wavelengths are more effective at targeting pilosebaceous, vascular and pigmentary changes, while longer wavelengths are most effective in the reduction of wrinkles through dermal remodelling55
.
The first RF device developed was the monopolar RF device ThermaCool (Thermage, Inc., Hayward, CA, USA; now Solta Medical, Inc.), which demonstrated improvement of skin laxity on the face and neck. The concept
The energy produced by RF develops a heat that is regulated according to the
tissue depth, from the superficial dermis down to the muscle border.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100