We present a new method of videodermatoscopy called the FAV method (Fluorescence-Advanced-Videodermatoscopy). The FAV method uses an opto-electronic system with a monochromatic light source with a wavelength of 405 nm (± 5nm). The optical device allows manual focusing of the image on different superficial layers of the skin. The field of view is 340μm. The image sensor of the device is highly sensitive (>50% at λ = 400-810nm) and has a high frame rate (1 frame/8.33 ms). The principle of operation of the FAV is based on the ability of endogenous molecules to absorb specific wavelengths and emit fluorescence (Fluorescence is a phenomenon characteristic of some substances. When illuminated, they absorb radiation and emit visible light, i.e. light at higher wavelengths. This emission ceases as soon as the external illumination is removed).
The test is carried out in vivo and the optical device is applied directly to the skin. By adjusting the optical device, we can view different depths of the skin. The images are visualised on the screen in real time on a grey scale according to absorption levels (black without fluorescence, maximum fluorescence). To avoid energy diffusion at the surface due to corneum stratus, the skin surface is coated with glycerol. Under normal conditions, the optical penetration depth ranges from 200 to 400 μm, which allows visualisation of skin structures down to the papillary dermis.
The FAV technique allows a rapid, non-invasive (without skin damage) assessment of the status of superficial skin structures at the cellular level, providing additional information that may be relevant for the diagnosis and treatment of premalignant and malignant tumours of the skin (lenticular malignancy, melanoma, epithelial malignancy). The FAV method is also useful in the diagnosis of parasitic skin diseases, directly visualising pathogens in selected skin infections.
As an example, you can see two visually similar pigmented tumours, one of which is still an altered mole (atypical mole) and the other is an early melanoma.