/ drdavinlim
More on acne scars & how to treat
Lasers for acne scars
Picosure was the first picosecond laser made by Cynosure. This KZfaq post outlines my personal experience with this laser. This viewpoint may not be shared by other Dermatologists.
Background: Pico lasers have been marketed as the next generation Q-switch laser. Pico is the term used to describe the pulse duration of these lasers. Originally developed for faster and more effective tattoo removal, the employment of pico lasers extend to treatment of pore sizing, pigmentation, dermal remodelling/wrinkle treatments and acne scars.
Dermal science: in the context of acne scars, pico lasers perform two biological effects to remodel collagen. The first effect is on the top layer of the skin called the epidermis. With ultra-short pulse durations keratinocytes are literally blown apart. The result of this controlled epidermal injury is the formation of LIOB or laser induced optical breakdown. Picosure’s LIOBs are primarily located in the epidermis due to higher absorption of melanin, whist longer wavelength lasers such as Picoway, & PicoPlus have LIOBs in the upper dermis.
The proposed effects on collagen remodelling is secondary to the release of cytokines and growth factors generated from epidermal injury with a flow on effect in the dermis.
The second proposed effect of pico lasers in the context of scar remodelling is the ‘spring effect’ to the dermal layers. Shock waves from high energy and very short pulse travels into the dermal layers causing a cascade of events that results in stimulation of fibroblasts. This leads to new collagen formation.
Clinical practice: In the context of Picosure there are clinical indications that I select this laser over other energy devices. Firstly is the treatment of green tattoos. The 755 wavelength has a high absorption coefficient for greens over other wavelengths. The second indication is in the treatment of ethnic skin types (higher melanin content). This operating window is small- namely skin type 3 and above with off label over-pass with the focus fractional handpiece. In the context of a no downtime procedure to address pores, wrinkles and actinic pigmentation the pico laser has no peers. Clinical studies on Picosure, Picoway, and PicoPlus have all demonstrated similar outcomes.
Acne Scars and Pico: The first few papers sponsored by Cynosure outlined the somewhat spectacular claims of Picosure in the context of acne scars. One paper even stated that the outcome was ‘comparable to fractional CO2 lasers’, without the risks or downtime. I have tried to replicate the statements made by Cynosure from 2015- 2016 however I have not been successful, even with off label high energy over-passes. The histology and physics of this laser can not explain sufficient scar remodelling, except in the treatment of grade 1 acne scars, namely PIH or skin colour changes (darkening of skin). This improvement is based upon colour and NOT significant volume - depth of scar.
Subjective viewpoint on Picosure/Picoway & other pico lasers: Picosure was the first generation of pico lasers. The pros of this laser is the fact that it has the most amount of data. The cons include the lack of meaningful power, and the consumable Focus handpiece. The addition of both the 532 and 1064 filter for the Picosure is both futile and embarrassing as the laser lacks any meaningful power. IMO the Picoway - PicoPlus platforms are more flexible in the context of treating conditions such as birthmarks and resistant tattoos.
Summary: Acne scars should be treated according to the scar type. Picolasers are useful in the management of grade 1 scars. There are many more effective treatments for established acne scars.
Dr Davin S. Lim