Medical Research
 

Scarring

Definition

Scars are the result of an unpredictable "disorder" occurring during the healing process, whether from a "clean" surgical scar or post-traumatic scar.

Different techniques are used to reduce inflammatory scarring or to revive stagnant cicatricial processes; pulsed light is one of the treatments that respond to this process.

When a post-surgical scar occurs, collagen fibres, blood vessels, nerve endings and muscle fibres are partially destroyed. The body therefore triggers a series of reactions:

  • Inflammation phase,
  • Granulation phase,
  • Remodelling phase.

The process evolves over several months, between 6 and 36 months depending on individual cases, before the final and lasting appearance of a scar is determined.

Scarring varies from one individual to another because it largely depends on nutritional (malnutrition), metabolic, endocrinal and medicinal (prolonged use of corticosteroids) factors. Age is also an important factor, as is skin colour; this can have an impact on the appearance of the scar, which can be keloid and may well feature a protuberance.

Aim of the study

The aim of our study was to verify the impact of treatment using the W-O75 pulsed light device on target cells and to measure the decrease in side effects linked to the cicatricial process.

Operating W-O75

Due to W-O75’s characteristics, it’s possible to select just a portion of the light spectrum emitted by a flash tube at the moment of flashing. This is achieved by interposing one or more filters between the tube and the skin.

Optimum filtration provides a spectrum of light that’s absorbed selectively by the target area (fibroblast) – producing collagen, hyaluronic acid and elastin.

W-O75 has a filtration system adapted for the clinical indication being treated.

In addition, near infrared rays such as those emitted by W-O75 are already clinically used today in numerous applications that aim to improve skin quality, including the stimulation of endogenous collagen synthesis. In fact, infrared light significantly raises the temperature of tissue fluid, which is the effect of this application.

Finally, W-O75 has a flash duration determined by the treated target (fibroblasts), and is in correlation with the perfect homogeneity of the luminous intensity of the emitted flash.

Context

Pulsed light has been used for 20 years, either alone or in conjunction with other techniques or medication, to treat minor ailments or skin disorders such as hirsutism and hairiness, wrinkles, scar tissue and pigment disorders.

The light produced by pulsed light devices is absorbed by melanin (hairiness) or by haemoglobin (wrinkles, scars). The light energy is then converted into thermal energy, which, depending on the temperature reached, can:

  • either stimulate collagen generation (treatment of wrinkles, scarring or pigment disorders)
  • or, at higher temperatures, cause coagulation of protein (treatment for hairiness, for example).

With E-One then E-O75, E-Swin has used pulsed light to treat hirsutism and hairiness in general. E-O75’s foundation has been used to create W-O75 by changing the HMI (Human Machine Interface).

Study

The test was carried out with W-O75, using the same parameters as the mass-produced E-Swin devices: operating principle, settings, and identical optical, electronic and mechanical characteristics. It’s therefore a medical device entirely equivalent to the one currently marketed.

E-Swin deliberately chose to conduct its clinical study in vitro (cell culture) to measure W-O75’s performance, so that the results of this study would not be open to criticism. Indeed, published studies are usually performed on individuals and the performance demonstrated through before/after pictures. However, this method is questionable because the pictures can be edited afterwards or photos can be taken in different conditions: angle, light, etc.

A summary of the clinical study of W-O75

The only way to conclusively measure the performance of W-O75 was to measure, in vitro, changes in the following 3 parameters:

  • Collagen I
  • Elastin
  • Glycosaminoglycans

Several flash configurations were tested, and it was found that one stood out more than the others in increasing the production of collagen I, elastin and glycosaminoglycans. We chose this configuration for W-O75.

Only one patient was selected – a female patient in this instance – to sample cells because fibroblasts within the base of wrinkles are identical, irrespective of the person. Therefore it wasn’t necessary to select different people in order to have different sources for fibroblasts within the base of wrinkles.

Fibroblasts within the base of wrinkles are present in everyone from adulthood. However, they’re found in much larger amounts in the elderly. The choice finally fell on a 64-year-old – the most favourable age group for a rich sample of this type of cells.

This device requires prior training for professional use. The training covers two separate areas: the principles of pulsed light and its action on the target, and how to use the device.

Safety

The treatment’s safety was checked for skin types I to IV.

We note the characteristics of the energy implemented with W-O75, in comparison to a certified medical device that’s already been marketed for over 1 year for the treatment of hirsutism (E-O75). Luminous energy is distributed throughout the duration of the flash with W-O75. Thus, with a higher fluency than E-O75, the instantaneous luminous power delivered onto the skin, across the entire flash, is actually almost 4 times lower than that used in hair removal with E-O75.

The test conducted with W-O75 (identical to that marketed) also demonstrates the benefit of flashes on several types of cells:

  • Damaged cells, altered by surgery (scarring), as well as ageing cells.
  • Also, healthy cells remain viable; they’re not degraded by the flash.

In addition to establishing the optimal pulse duration, this test enabled operational safety at maximum power to be checked.

Finally, the risk of overheating or even burning was also taken into account and assessed during the risk analysis. No unacceptable risk was identified after control measures were applied.

Summary of key findings

The test demonstrated:

  • the lack of cytotoxicity of IPL flashes for healthy fibroblasts within the base of wrinkles
  • an increase (within certain parameters) in the production of collagen, elastin and glycosaminoglycans for cells involved in wound healing.

The technology behind W-O75, as demonstrated on fibroblasts, increases the secretion of these 3 elements. As these 3 elements are heavily involved in post-surgical wound healing, an increase in their secretion will therefore bring about a welcome improvement in the healing process.