Skin Photoaging

Compared to healthy skin, chronic and continuous sun exposure, or tanning, results in an aberrant and disorderly maturation of keratinocytes and an increase in cellular binding and adhesion.Desquamation will diminish due to the mentioned factors, resulting in a rough and thicker stratum corneum with a decreased barrier function. The skin’s rough texture causes dullness (yellow-gray) and skin discoloration.Water loss and dehydration occur due to the epidermis’s malfunction and inability to act properly as a barrier. The penetration of the irritant will dramatically increase, producing allergic responses and erythema.Additionally, photoaged skin exhibits pigmentary alterations due to hyperactive melanocytes and disordered melanin deposition in the epidermis. Regions with an excess of melanin show hyperpigmentation, whereas regions with a deficiency of melanin appear to have hypopigmentation.

Photoaging Causes

Chronic UV exposure has several detrimental consequences on the extracellular matrix in the dermis. Collagen and other structural proteins are destroyed and weakened due to the increased activity of enzymes (e.g., matrix metalloproteinases).The combination of collagen degradation and decreased collagen synthesis creates fine lines, wrinkles, and scars. Solar elastosis occurs in some cases of severe photoaging and is characterized by tangled masses of degraded elastin protein in the dermis. It manifests clinically as coarse wrinkling, sallow colouring, and skin thickness.It is typical for cutaneous blood vessels to dilate abnormally, resulting in noticeable face erythema and telangiectasia.

Photoaged skin and skin Rejuvenation

The gold standard of treatment for photoaged skin indications and lesions is laser treatment. Other treatments, such as PRP, microneedling and Hyrdafacial, could also be used effectively.

• Microdermabrasion combines a mechanical peel with an injection of serums such as salicylic acid.
• Fraxel nonablative dual fractional laser for skin tightening.

Lasers

Colour-blind lasers

The laser affinity for water determines the penetration depth of these lasers. Short wavelengths, such as 1320 nm, absorb less water and penetrate deeper into the skin, whereas longer wavelengths, such as 1450 nm, absorb more water and penetrate superficially. These lasers are suitable for use on all skin types.Water-targeting fractional lasers (1410 nm, 1440 nm, 1540 nm, 1550 nm, 1565 nm, and 1927 nm) are the most recent addition to the class of nonablative lasers used for skin resurfacing. The Fraxel 1550 nm was the first fractional non-ablative wavelength to treat photoaged skin.The depth of penetration of these lasers is also determined by their affinity for water, with shorter wavelengths, such as 1550 nm, exhibiting lower water absorption and greater cutaneous penetration. This results in more significant dermal effects such as collagen remodelling and reduction of dermal dyschromia such as melasma.Longer wavelengths, such as 1927 nm, absorb more water and penetrate deeper into the skin, making them ideal for treating epidermal pigmented lesions such as lentigines and ephelides. These lasers are safe for all skin types, but caution is suggested for darker skin types due to the possibility of photo-induced hyperpigmentation.Other devices, such as the Icon Max1540 TM, Cynosure/ Palomar, use a stamping technique in which a lens inside the handpiece fractionates the beam each time the laser pulses and all pixels are generated simultaneously.Certain systems employ scanners to fractionate the beam into successive pixels, either in a predetermined pattern or randomly scattered throughout the skin treated during the pulse.

Colour Sensitive Lasers

These lasers target melanin and Oxyhemoglobin. Non-fractional lasers (532 nm, 585 nm, 595 nm, 755 nm, 1064 nm, strong pulsed light) target melanin and Oxyhemoglobin. They are generally utilized to treat vascular ectasias and pigmented lesions due to their strong absorption by coloured tissue chromophores.Historically, vascular lesions have been treated using 532 nm and pulsed dye 585 nm and 595 nm lasers. Recent technological developments in these devices (bigger spot sizes and longer pulse widths) have increased cutaneous penetration and improved their safety profiles, allowing them to be used for wrinkle removal while minimizing the danger of purpura.

The Yag Laser

The 1064 nm (Nd:YAG) laser is a non-fractional laser frequently used for skin resurfacing. This laser targets multiple chromophores (water, melanin, and Oxyhemoglobin). However, the long wavelength enables deep dermal penetration and effectively skips epidermal melanin, making it suitable for all skin types.

The Yag laser has three pulse widths:

Long pulse mode (e.g., Laser Genesis TM, Cutera) in the millisecond rangeShort pulse modes (e.g., RevLite ®, Cynosure/ ConBio) are Q-switched lasers in the nano-second rangeUltrashort Pulse modes are in the pico-second rangeThe Yag has demonstrated histological and clinical reductions in wrinkles and other collagen remodelling effects, such as pore size reduction, smoother skin texture, and reduction of superficial acne scars.The Q-switched 1064 nm lasers are frequently used to correct cutaneous pigmentation such as melasma and tattoo removal.Read more about the topicPost 1022Post 1023Post 1024Post 1205