Hydradermabrasion through the lens of Line‐Field Confocal Optical Coherence Tomography

Abstract

Background

Hydradermabrasion, also known as “HydraFacial,” is an exfoliative cosmetic procedure for skin rejuvenation that has gained popularity. Despite its increasing popularity, clinical studies validating its efficacy with non‐invasive assessment of histological changes to the skin, are scarce. In this study, we used Line‐Field Confocal Optical Coherence Tomography (LC‐OCT), an optical imaging device, to non‐invasively visualize microscopic changes to skin anatomy after hydradermabrasion treatment.

Materials/Methods

Eight volunteers (Fitzpatrick skin types II–V) were recruited for this study. Images, using LC‐OCT (DeepLive, DAMAE medical) were obtained before and after hydradermabrasion and at 2 weeks post‐treatment. A commercially available hydradermabrasion device was utilized to perform the dermabrasion.

Results

In the epidermis, initially, a decrease in the average thickness of the stratum corneum, from 9.42 to 6.67 µm was visualized in LC‐OCT images after hydradermabrasion. However, at 2 weeks of follow‐up, the average stratum corneum thickness was 9.75 µm, resulting in an overall increase in the average thickness after treatment. Improved homogenization of the stratum corneum and decreased number of undulations in the epidermis post‐treatment were also visualized. In all the subjects, the superficial dermis appeared stretched, which returned to baseline by the 2‐week follow‐up. At the 2‐week follow‐up, there were no visible differences in the quality and quantity of collagen fibers in the dermis.

Conclusion

In our study, LC‐OCT images of the epidermis and dermis demonstrated microscopic features of skin rejuvenation when treated with hydradermabrasion. Thus, not only highlighting the efficacy of hydradermabrasion but also the potential of LC‐OCT to serve as a tool for visualizing the microscopic effects of cosmetic procedures on skin anatomy.

1. INTRODUCTION

Hydradermabrasion, also known as “HydraFacial (HF)” or “wet dermabrasion,” is an alternative to traditional microdermabrasion, using abrasive crystals for skin rejuvenation. It involves a combination of suctioning and gentle cleansing of the skin with water and other additive serums to give the skin a more youthful appearance. ¹ During the procedure, a handheld suctioning wand emitting a stream of water is moved across the skin, traditionally on the face. ¹ A process claimed to gently exfoliate, cleanse, and hydrate skin by delivering water and other hydrating serums such as hyaluronic acid. It is also marked to unclog pores, remove dead skin cells, and nourish the skin.

Although previous studies demonstrated clinical improvement of skin appearance with hydradermabrasion, studies evaluating its microscopic effects on the skin are scarce. ¹ , ² In this study, we used Line‐Field Confocal Optical Coherence Tomography (LC‐OCT) to visualize subsurface cellular‐level early changes associated with hydradermabrasion treatment. LC‐OCT is a non‐invasive diagnostic modality that combines the high resolution of reflectance confocal microscopy (RCM) (1.3 µm) and the vertical depth of optical coherence tomography (OCT) (500 µm) to create three‐dimensional block skin images. ³ LC‐OCT studies on healthy skin have enabled qualitative and quantitative analysis of epidermal thickness, dermal‐epidermal junction undulation, cell density, and the number of cell layers. In addition, LC‐OCT has been used to visualize features of dermatological pathologies including pustular skin disorders, psoriasis, eczema, lichen planus, melanoma, dysplastic nevi, nevus, basosquamous carcinoma, basal cell carcinomas, squamous cell carcinoma, and actinic keratosis. ⁴ , ⁵ , ⁶ , ⁷ , ⁸ , ⁹ , ¹⁰ , ¹¹ Therefore, using LC‐OCT, we aim to better elucidate the early cutaneous surface and subsurface kinetic effects of hydradermabrasion, through LC‐OCT, as its use in cosmetic dermatology continues to grow.

2. MATERIALS AND METHODS

In this prospective study, we assess and quantify early subsurface anatomical changes seen in the skin after facial hydradermabrasion. Eight volunteers with Fitzpatrick skin types (II–V) were recruited for this study. Written consent was obtained from all subjects after explaining the study procedures. Imaging was performed before and after hydradermabrasion, and at 2 weeks post‐treatment, using LC‐OCT (DeepLive, DAMAE medical) and VISIA (CANFIELD Imaging Systems, NJ, USA). Prior to the procedure, subjects were instructed to wash their faces with a mild cleanser and wait for the skin to dry. Subjects were advised to wear a headband and a goggle. A commercial hydradermabrasion device was utilized to perform the dermabrasion. Suction intensity and the number of passes were decided depending on the desired results and subjects’ sensitivity. The direction of the handheld wand is shown in Figure 1. Contiguous passes were applied on the entire face and the “kiss and twist” method was applied over the nostrils. The forehead was performed first followed by cheeks, chin, mouth, and nose. The skin was stretched with two fingers while moving the handheld wand to allow for smooth gliding. Patients were surveyed on the improvement of skin texture immediately after HF by self‐tactile evaluation of the face to report either no change, improved, or worsened skin texture. In addition, patients were asked to evaluate self‐tactile smoothness. After a week, patients were called to ask if they experienced any adverse effects and if they were satisfied with the treatment.

FIGURE 1.

Direction of hydradermabrasion wand on the face.

3. RESULTS

3.1. LC‐OCT

3.1.1. Epidermis

On OCT,vertical view (figure 2), the pre‐treatment epidermis had abundant peaks and troughs on the surface and the stratum corneum appeared thick. Changes in the thickness of the stratum corneum were measured (Chart 1). After hydradermabrasion, initially, there was a visible reduction in the thickness of the stratum corneum. The average thickness before treatment was 9.42 µm, and the thickness after treatment was 6.67 µm. However, at 2 weeks post‐treatment, there was an increase in stratum corneum thickness in five subjects, which resulted in an overall increase in the average thickness. The average stratum corneum thickness was 9.75 µm at 2 weeks post‐treatment. Visible exfoliation was seen and calculated in all subjects except one. There was also a visible reduction in the number of peaks and troughs. The number of undulations was calculated, and the average number of undulations before treatment was 7.12. After treatment, there was a significant reduction in the average number of undulations, which decreased to 5.75. Two weeks post‐treatment, the average number of undulations was 5.87.

FIGURE 2.

Vertical,optical coherence tomography, view of LC‐OCT. (1.A) Pre‐hydradermabrasion (abundant peaks and troughs on the surface and the stratum corneum appears thick). (1.B) 10 mins post‐hydradermabrasion (visible reduction in the thickness of the stratum corneum). (2.A) Pre‐hydradermabrasion (abundant peaks and troughs on the surface and the stratum corneum appears thick). (2.B) 10 mins post‐ hydradermabrasion (visible reduction in the thickness of the stratum corneum). White scale bar represents 100 µm.

CHART 1.

Assessment of thickness of stratum corneum pre and post‐hydradermabrasion.

In confocal, enface view (Figure 3), inflammation was visible in subjects after treatment. Subjects who underwent mild treatment exhibited few small bright inflammatory cells (Figure 3B). In comparison, subjects who underwent moderate/severe treatment showed a greater level of inflammation, characterized by a greater number of bright inflammatory cells, spongiosis, and larger size of blood vessels after treatment (Figure 3C). This pattern of inflammation is mild compared to other inflammatory patterns (pinpoint inflammation and globular inflammatory cells) seen in another exfoliative procedure, chemical peel. ¹²  Before treatment, the average size of blood vessels was 13.5 µm. After treatment, the average size increased to 28.5 µm, indicating an increase in blood flow caused by the treatment. Two weeks post‐treatment, the average blood vessel size was 20.87 µm, reflecting an increase in blood supply to the facial skin, 2 weeks post‐treatment. Inflammation was not visible at 2 weeks after treatment.  

FIGURE 3.

Confocal microscopy, enface, view of LC‐OCT. (A) Pre‐HF (B) 10 mins post‐HF (mild HF, small bright inflammatory cells). (C) 10 mins post‐HF in another subject (moderate HF, greater number of bright inflammatory cells, and spongiosis after treatment). White scale bar represents 100 µm.

3.1.2. Dermis

After hydradermabrasion, the superficial dermis appears stretched as demonstrated by an increase in the size and spacing between collagen fibers (Figure 4B). This temporary effect may be explained by the inflammatory response, increased blood circulation, and heat generated by the procedure. At the 2‐week follow‐up, subjects who underwent mild treatment had their dermis return to baseline level (Figure 4C). Even in subjects with moderate/severe treatment, there was no visible difference seen in the quantity and quality of collagen fibers as compared to baseline images.

FIGURE 4.

Confocal microscopy, enface, view of LC‐OCT. (1.A) Pre‐HF. (1.B) 10 mins post‐HF (moderate HF, dermis appears stretched as demonstrated by an increase in the size and spacing between collagen fibers). (2.A) Pre‐HF. (2.B) 2 weeks post‐HF (moderate HF, dermis returns to baseline level, there is no visible difference seen in the quantity and quality of collagen fibers as compared to baseline images).

3.2. VISIA skin analysis

VISIA skin analysis was done (Figure 5). Subjects that underwent mild treatment did not experience any visible redness post‐treatment. At the 2‐week follow‐up, there was no improvement in fine lines, overall red areas of the face or clogged pores. However, subjects that underwent moderate/severe treatment experienced visible erythema post‐treatment. At the 2‐week follow‐up, a decrease in red areas and fine lines were visible.

FIGURE 5.

Clinical pictures acquired by VISIA. (A) Pre‐HF. (B) 10 mins post‐HF. (C) 2 weeks post‐HF (improvement in global appearance). Red area analysis (D) pre‐HF (E) 10 mins post‐HF (F) 2 weeks post‐HF (reduction in red areas). Clinical pictures showing improvement in fine lines (G) Pre‐HF (H) 10 mins post‐HF (I) 2 weeks post‐HF (reduction in fine lines on forehead).

3.3. Subjective assessment

All subjects (8/8) reported a difference in texture and smoothness after tactile evaluation of their face.

3.4. Post microdermabrasion follow‐up and adverse effects

All subjects reported satisfaction with the procedure. No subjects reported acne breakouts, skin irritation, skin dryness, or post‐inflammatory hyperpigmentation after the treatment. Subjects that underwent mild HF did not experience any visible redness but subjects who underwent moderate/severe HF experienced visible redness that resolved after 2–5 days.

4. DISCUSSION

Hydradermabrasion combines microdermabrasion without using abrasive exfoliants. A study by Freedman et al. used antioxidant serum with hydradermabrasion and compared them to volunteers without hydradermabrasion. ¹ In the group treated with the combination of antioxidant serum and hydradermabrasion, histology revealed statistically significant increases in epidermal thickness, papillary dermal thickness, and polyphenolic antioxidant levels. ¹ In addition, improvements were seen in the dermis including collagen hyalinization and increased fibroblast density which were corroborated by decreased visual appearance of rhytids, pore size, and dyspigmentation. ¹ Thus, hydradermabrasion also allows for enhanced and simultaneous penetration of the product.

Another multicenter, open‐label study by Storgard et al. showed increased efficacy of hydradermabrasion when combined with the application of blue light therapy for the treatment of acne vulgaris. ² In the study, more than 80–100% of both investigators and patients agreed or strongly agreed there was improvement in skin appearance, at final treatment. ² Therefore, for difficult‐to‐treat conditions such as acne scars, a multimodal approach may be preferable.

LC‐OCT is a potential non‐invasive tool for treatment monitoring and studying the effect of cosmetic procedures on skin anatomy. ¹³ , ¹⁴ Without histologic criteria, the evaluation of clinical and cosmetic improvement is subjective. In our study, LC‐OCT correlates with histologic features of increased epidermal thickness after microdermabrasion, when measured after 2 weeks. The advantage of LC‐OCT is that the patient can be monitored over long periods to study the progressive effects of treatments which would be limited in studies using only a histologic approach. This non‐invasive modality also reduces the risk of scarring, infection, or dyspigmentation. Furthermore, the use of LC‐OCT for treatment monitoring, enables cosmetic treatments to be individualized to optimize results.

5. CONCLUSION

In summary, this study highlights the unique position of LC‐OCT in studying the kinetics of sequential changes and treatment monitoring of hydradermabrasion. Our results indicate that mild treatment is indicated for individuals wanting smoother skin without any erythema or bruises. Moderate/severe treatment is indicated for individuals wanting improvement in skin redness and fine lines but are content with erythema and bruises for 3–5 days. This tool has the potential to evaluate the efficacy and further the understanding of the cellular physiological effects of various dermatological procedures. Further studies evaluating the use of LC‐OCT findings and how it may be used to guide treatment decisions or management are needed to determine its feasibility.

CONFLICT OF INTEREST STATEMENT

The authors declare no conflict of interest.

ETHICS STATEMENT

All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by Advara, Pro00035376.

INFORMED CONSENT

The authors affirm that patients signed informed consent regarding publishing their data and photographs.

Razi S, Truong TM, Khan S, Sanabria B, Rao B. Hydradermabrasion through the lens of Line‐Field Confocal Optical Coherence Tomography. Skin Res Technol. 2024;30:e13684. 10.1111/srt.13684

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.