PROCEEDINGS ARTICLE | March 4, 2014
Proc. SPIE. 8934, Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XVIII
KEYWORDS: Optical imaging, Light emitting diodes, Real time imaging, Photodynamic therapy, Optical coherence tomography, Skin, Biopsy, Optical diagnostics, In vivo imaging, Tissue optics
Photodynamic therapy (PDT) promotes skin improvement according to many practitioners, however the immediately in
vivo assessment of its response remains clinically inaccessible. As a non-invasive modality, optical coherence
tomography (OCT) has been shown a feasible optical diagnostic technique that provides images in real time, avoiding
tissue biopsies. For this reason, our investigation focused on evaluates the PDT effect on a rodent model by means of
OCT. Therefore, a normal hairless mouse skin has undergone a single-session PDT, which was performed with topical 5-
aminolevulinic acid (ALA) cream using a red (630 nm) light emitting diode (LED) which reached the light dose of 75
J/cm2. As the optical imaging tool, an OCT (930 nm) with axial resolution of 6.0 microns in air was used, generating
images with contact to the mouse skin before, immediately after, 24 hours, and 2 weeks after the correspondent
procedure. Our result demonstrates that, within 24 hours after ALA-PDT, the mouse skin from the PDT group has shown
epidermal thickness (ET), which has substantially increased after 2 weeks from the treatment day. Moreover, the skin
surface has become evener after ALA-PDT. Concluding, this investigation demonstrates that the OCT is a feasible and
reliable technique that allows real-time cross-sectional imaging of skin, which can quantify an outcome and predict
whether the PDT reaches its goal.
