Introduction: Elastic fibers are constituents of the dermal extracellular matrix, determining the histoarchitecture of the
dermal connective tissue. Organization and density of elastic fibers change as skin ages. The aim of this paper was to determine the similarities and differences between the photo-aging and the physiological aging of skin by examining organization and quantifying the elastic fibers in the dermis during aging. The material included samples of photoexposed and photoprotected skin, obtained from 90 cadavers aged 0-82 years. The samples were classified into five age groups: newborns, young age, middle age, mature age and the oldest age. Skin samples were stained using the Halmi modification of Aldehyd fucshin staining method, as well as Alcian blue staining (the Spicer method). Volume density (VD) of the elastic fibers was measured using Image J program.

Results: In the skin of newborns and young age group (neck and abdomen) elastic fibers appeared to form a network structure. In the photoexposed skin of the mature age and the oldest group, elastic fibers showed tendency to fragment, while the elastic material exhibited tendency to accumulate. VD of elastic network in the skin of the neck in the middle, mature and the oldest age group was greater than VD of abdominal skin of the respective age groups (3.66±0.28%, 5.61±0.22%, 6.24±0.21% respectively). Age-related statistically significant increase in VD of the elastic network in the skin of the neck, as well as a statistically significant reduction of elastic network VD in the abdominal skin, has been observed (middle age - oldest).

Conclusion: Correlation of the organization and quantity of elastic fibers with age exhibits different pattern in photoexposed compared to photoprotected skin. A quantitative evaluation of the volume density of elastic fibers correlates with clinically visible signs of photo-aging, primarily with solar elastosis.