Evaluation of elastin fibres in young and aged eyelids and abdominal skin using computational 3D structural analysis

Background Aging‐related degeneration of elastic fibres causes skin wrinkles and loss of elasticity. A correlation has been reported between dermal elastic fibre degradation and wrinkles. However, the mechanism of wrinkle formation is complex and unclear. To establish methods for treating wrinkles, it is necessary to understand the aging‐related morphological alterations underlying elastin fibre degradation or disappearance. Objectives To image and analyse aging‐related three‐dimensional (3D) morphological alterations of elastic fibres in the eyelid and abdominal skin. Methods Excised human eyelid and abdominal skin tissues were examined. The structure of elastic fibres in the skin tissues was examined via nuclear, tropoelastin and fibrillin‐1 immunostaining. Then, 3D imaging was performed using a confocal laser microscope and tissue decolourization technology. Images were analysed using a computational method. Results The decolourization technology made it possible to image elastin fibres in 3D, and we devised a method for analyzing the elastin fibre structure using computational methods. It was quantitatively shown that the eyelid skin has a more complex fibrous structure than the abdomen, and the fibres became curved, shortened and thickened with age. Conclusions We provide a novel 3D analysis method for elastin fibres and report age‐related alterations in elastin fibre structure in the human eyelid and abdominal skin. This method contributes to the understanding of elastin fibre degeneration in more detail than conventional methods. Applying this 3D analysis method to skin tissues will contribute to a better understanding of age‐related changes in fibres and to the development of novel wrinkle treatments.