Chronic inflammatory skin diseases, such as atopic dermatitis, psoriasis, acne, or pemphigus vulgaris, significantly impact patients’ quality of life and overall health. To better understand these conditions and evaluate potential treatments, researchers rely on preclinical dermatology models, mostly in mice. Traditionally, they require post-mortem sampling. Imavita proposes an innovative shift: applying Optical Coherence Tomography (OCT), a non-invasive imaging technique, to perform in vivo skin lesion assessment. Discover our results, presented at AFSTAL, La Rochelle, France.
Advantages of Optical Coherence Tomography (OCT) in Preclinical Dermatology ModelsOCT offers multiple advantages over conventional techniques:
These features make OCT ideally suited for longitudinal, in vivo evaluation of inflammatory skin lesions. |
The clinical context: High prevalence of inflammatory skin diseases
Inflammatory skin diseases are highly prevalent and burdensome, both clinically and socially.
Atopic dermatitis (AD) affects 10–30% of children, depending on the population studied. This makes it one of the most common pediatric dermatological conditions worldwide. Its impact extends into adulthood, with nearly 10% of individuals aged 20–30 affected (Vidal), highlighting its chronic and relapsing nature. Clinically, AD is characterized by erythematous, excoriated plaques associated with intense pruritus, leading to disrupted sleep, psychological distress, and impaired quality of life.
Another common inflammatory skin condition is psoriasis. Although less prevalent than atopic dermatitis, it affects 1–3% of the global population, including both children and adults, and remains a considerable public health concern. In addition to its cutaneous manifestations, psoriasis is associated with serious systemic comorbidities. Approximately 20% of patients develop severe forms, often accompanied by joint involvement (psoriatic arthritis), which significantly worsens patient outcomes (Inserm). Chronic inflammation and social stigma linked to the disease, further contribute to mental health deterioration in affected individuals.
Given the burden and complexity of these diseases, there is a pressing need for innovative preclinical models to advance our understanding and accelerate the development of effective therapies.
Optical Coherence Tomography (OCT): A powerful imaging technology
Optical Coherence Tomography is a relatively recent, non-invasive medical imaging technique. Comparable to ultrasound, it uses near-infrared light instead of sound waves. OCT enables high-resolution visualization of the superficial layers of the skin, reaching several millimeters in depth.
How it works?
An electromagnetic wave (in the near-infrared range) is partially reflected by biological tissues. These reflections are compared with a reference beam, and the data is processed to reconstruct highly detailed cross-sectional images, with a resolution of a few microns.
Physical principle of OCT: the Michelson interferometer
OCT is based on the principle of the Michelson interferometer, an optical setup that measures interference patterns between electromagnetic waves.
Light from the source is split into two beams:
- One beam travels through the reference arm, is reflected by a mirror, and passes back through the beam splitter.
- The other beam travels into the sample arm, where it is reflected by tissue structures.
When the two beams are recombined, they produce interference patterns. Analyzing these patterns allows for the highly precise visualization of tissue microarchitecture, with resolution on the order of one micron.
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Limitations of traditional approach to validating skin inflammation models
Preclinical skin models are typically assessed using post-mortem histology, which requires sacrificing animals and delays results by several weeks. Validation is based on parameters such as:
- Epidermal and dermal thickness
- Hyperkeratosis, Parakeratosis
- Lipid barrier status
- Immune cell infiltration
- Cytokine levels
While precise, these approaches lack the ability to track changes dynamically over time in the same subject.
Imavita’s experimental: A non-invasive shift
Imavita implemented OCT in a validated oxazolone-induced atopic dermatitis model in hairless SKH-1 mice.
Protocol and study timeline:
- Day 1: Sensitization with oxazolone (control group: ethanol)
- Days 8–29: 11 challenges + treatments + clinical evaluations
- Day 30: Final measurements, clinical scoring, and tissue collection
Epidermal thickness was measured in vivo at multiple time points using OCT. These measurements were then compared to traditional histological analyses (microscopic examination of skin sections).
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Comparison of tomography and histology results
Notable results on the benefits of tomography compared with histology:
- Strong correspondence between OCT and histological measurements
- OCT enables rapid follow-up (5 minutes per scan), compared with several weeks for histological analysis
- Effective visualization of epidermal thickening in inflamed areas
Supporting scientific evidence
The relevance of OCT in skin research is also supported by the literature:
- Wu et al. (2012) demonstrated that OCT can quantify epidermal thickness and optical attenuation coefficients, distinguishing between chronological and photoaged skin in mice.
- Schuetzenberger et al. (2020) showed that OCT allows longitudinal, volumetric assessment of intradermal hydrogel implants, confirming its precision and repeatability for tracking tissue changes over several months.
These findings align with Imavita’s observations and reinforce the scientific legitimacy of OCT in preclinical dermatology models.
(CTA)
Contact Imavita to explore how Optical Coherence Tomography can enhance your dermatology research models.
Why is OCT a turning point for animal models?
This imaging technique offers a more ethical approach, aligned with the 3Rs principles adopted by Imavita, while also being more efficient and scientifically robust.
- Fewer animals required
- Dynamic follow-up over time on the same subject
- No pain or heavy anesthesia
- Immediately usable results
Perspectives: expanding the use of Optical Coherence Tomography to other research areas
Following its success with atopic dermatitis, other models are currently being validated at IMAVITA:
- Psoriasis model in mice
- Pemphigus vulgaris in mouse
- Medical device validation (micro-needles)
- Ophtalmology / ocular disease
- Wound healing models
- Potential expansion to oncology
Optical Coherence Tomography has the potential to transform preclinical dermatological research. Non-invasive, fast, and repeatable, it offers a powerful alternative to conventional histological methods. This marks a step toward more modern, 3Rs-compliant, and efficient science.
Discover our advanced preclinical imaging solutions
Sources :
Communication presented at the 45th Afstal Colloquium (La Rochelle, France, 2019)
Eric Lacoste et al. IMAVITA, Canal Biotech 1, Parc Technologique du Canal, 3 rue des Satellites, 31400 TOULOUSE, FRANCE. Site: www.imavita.com E-mail: info@imavita.com