Understanding Lasers and Skin

Laser skin rejuvenation is a powerful cosmetic technique that uses concentrated light energy to address various signs of skin ageing and imperfections. As technology has advanced, lasers have become an integral part of skin aesthetics, helping to target fine lines, wrinkles, age spots, acne scars, pigmentation, and overall skin tone and texture. Here, we’ll explore the science behind lasers for skin rejuvenation, the different types of lasers available, what each type can achieve, and how these treatments work to renew and revitalise the skin.

How Laser Skin Rejuvenation Works

Lasers work by delivering concentrated beams of light to specific areas of the skin. This light energy is absorbed by target molecules within the skin. These molecules are termed ‘chromophores’ and each chromophore differs for the wavelength being utilised. The chromophores we target are: haemoglobin (blood), melanin (pigment) and water . When absorbed, the energy converts to heat, creating controlled damage that stimulates the body’s natural healing process. During this healing, new collagen and elastin fibres are formed, leading to firmer, smoother, and healthier-looking skin.

Laser treatments differ in terms of their wavelength, intensity, and how deeply they penetrate the skin. The two primary categories are ablative and non-ablative lasers:

• Ablative Lasers: These are more aggressive and remove the outer layer of skin (epidermis) while heating the underlying layer (dermis). This dual action promotes collagen production and is highly effective for deep wrinkles, significant sun damage, and scarring. Ablative lasers generally require a longer downtime but deliver more dramatic results.
• Non-Ablative Lasers: These do not remove the outer layer of skin. Instead, they penetrate into the dermis, heating the tissue to stimulate collagen production without significant downtime. Non-ablative lasers are often used for less severe ageing signs, improving skin texture and tone with fewer side effects but may require multiple sessions.

Types of Lasers for Skin Rejuvenation

1. Fractional Lasers

   • How They Work: Fractional lasers can be either ablative or non-ablative, and they work by creating microscopic treatment zones in the skin. This means only a portion of the skin is treated at a time, leaving surrounding tissue intact, which speeds up healing.
   • Popular Technologies: The Fraxel laser is one of the most recognised fractional devices. In the clinic we utilise the Enlighten SR - a picosecond device, with an attachment hand piece that allows for fractionation.
   • Ideal For: Reducing fine lines, sun damage, age spots, acne scars, and improving skin texture.
   • Benefits and Downtime: Fractional lasers offer effective results with less downtime compared to traditional ablative lasers, but they still may require multiple sessions for optimal results.

2. CO₂ (Carbon Dioxide) Lasers

   • How They Work: CO₂ lasers are ablative lasers that vaporise the top layers of skin, creating deeper, controlled wounds that stimulate intense collagen production during healing.
   • Ideal For: Treating deep wrinkles, significant sun damage, texture issues, and acne scars.
   • Benefits and Downtime: CO₂ lasers produce dramatic results, but they come with considerable downtime (up to two weeks) and a risk of side effects like redness, swelling, and hyperpigmentation, especially in darker skin tones.

3. Er (Erbium) Lasers

   • How They Work: Er lasers are often used as an alternative to CO₂ for ablative resurfacing, but they’re more precise and cause less heat damage to surrounding tissue.
   • Ideal For: Fine to moderate wrinkles, acne scars, and pigmentation issues.
   • Benefits and Downtime: Er treatments are effective at resurfacing lighter skin tones but they come with considerable downtime (up to two weeks) and a risk of side effects like redness, swelling, and hyperpigmentation, especially in darker skin tones.

4. Pulsed-Dye Lasers (PDL)

   • How They Work: Pulsed-dye lasers target blood vessels under the skin by emitting light that is absorbed by haemoglobin, making them effective for vascular lesions and redness.
   • Ideal For: Rosacea, broken capillaries, and vascular birthmarks.
   • Benefits and Downtime: Minimal downtime, with side effects often limited to temporary redness or bruising. Results are typically seen after a series of sessions.

5. Nd:YAG Q-Switched Lasers

   • How They Work: These lasers emit a wavelength that can penetrate deep into the skin, allowing for effective treatment of deeper pigmentation issues and blood vessels.
   • Ideal For: Treating vascular lesions, melasma, deep pigmentation, and some types of tattoos.
   • Benefits and Downtime: Nd:YAG lasers are particularly effective for darker skin tones, with minimal downtime, but require multiple sessions for best results.

Key Considerations in Laser Skin Rejuvenation

1. Skin Type and Colour: Different lasers interact with skin pigmentation in various ways. For example, non-ablative lasers like Nd:YAG are safer for darker skin tones, while ablative lasers like CO₂ are generally more suitable for lighter skin to reduce risks of hyperpigmentation.
2. Condition Severity: Ablative lasers may be better suited for those with deeper wrinkles or scars, while non-ablative lasers are effective for mild to moderate signs of aging.
3. Downtime: The choice between ablative and non-ablative lasers largely depends on how much downtime you can accommodate. Ablative lasers require longer healing, while non-ablative lasers allow for quicker recovery.
4. Number of Sessions: Non-ablative and fractional lasers often require a series of treatments for optimal results, while ablative lasers may achieve desired results in one session but with more downtime.

The Science of Collagen Stimulation

One of the primary goals of laser skin rejuvenation is to stimulate collagen, the structural protein that maintains skin firmness and elasticity. As we age, collagen production naturally declines, leading to wrinkles and sagging. The controlled damage from lasers kickstarts the body’s healing response, prompting the fibroblasts in the dermis to produce new collagen. Over the weeks following treatment, this collagen remodelling smooths out fine lines and wrinkles and improves skin elasticity and texture.

Potential Side Effects and Risks

While lasers are generally safe and effective, potential side effects include:

• Redness and Swelling: Common with both ablative and non-ablative lasers, typically subsiding within a few days.
• Pigment Changes: Hyperpigmentation or hypopigmentation, especially in darker skin tones, can be minimised by choosing the appropriate laser and using proper post-care.
• Crusting/Oozing: Oozing and crusting can occur with the more aggressive lasers, like Erbium and CO2, where the epidermis is generally fully traumatised and often oozes plasma - known as exudate.
• Scarring: Rare but possible with aggressive treatments like CO₂ lasers. Choosing an experienced provider helps mitigate this risk.

Laser Skin Rejuvenation Results

The results from laser treatments are cumulative, meaning that the effects improve over time as collagen continues to regenerate. Many patients start seeing improvements in skin texture and tone within a few weeks, with full results appearing after several months. Results from ablative lasers can last for several years, while non-ablative treatments may require maintenance sessions.

All in all laser skin rejuvenation is an effective option for patients looking to improve skin texture, tone, and signs of ageing. Understanding the differences among laser types, and choosing a treatment suited to your skin type and goals, is essential for achieving optimal results. Consulting a qualified clinician can help determine the best laser approach for your individual needs, ensuring a safe, effective path to renewed, youthful skin.