Quantitative and kinetic evolution of wound healing through image analysis

To define a healing function based on parameters measured on digitized imag es of wounds, and to use it to compare the rate of healing of two skin graf t donor sites, one treated with petrolatum gauze (Pg) and the other with a topical preparation containing alginates (A), Digital photographs of donor sites (depth 0.6 mm) taken every two days betw een day 6 and day 12 were analyzed blind using the same algorithm, followin g changes in color and homogeneity. Analysis of variance was used to identi fy those parameters that changed during healing, The healing function was c onstructed using measurements made in six patients (group 1) randomly chose n from ten requiring skin grafts, and was applied and validated using data from the remaining four patients (group 2). The results given by this heali ng function were compared with those provided by principal component analys is. The most significant healing parameters were those measuring wound homogene ity, and our healing function reflects how these change with time. The time -dependent curves of the function calculated for groups 1 and 2 matched wel l enough to be considered as being derived from the same set of measurement s. The results given by this healing function explained, by analogy, the me aning of the first principal component of principal component analysis. From day 6 to day 12, the healing function followed the same time-course fo r the Pg and A treatments, but healing was achieved significantly earlier ( 4 days, p < 0.03) with A. This suggests that the effect of A on wound heali ng is achieved in the first six days, before the visual changes from epider malization are analyzable.