Digital image analysis-based predictors of effective permanent make-up removal with laser and chemical remover

Unsatisfactory eyebrow permanent make-up (PMU) may negatively affect the well-being of patients. The aim of this study was to objectively assess the effectiveness of removing eyebrow PMU using laser or laser combined with chemical remover. It also analysed colour-related predictors of effective removal of permanent make-up. The study involved 75 patients (mean age 42.8 ± 10 years) who underwent eyebrow PMU removal using laser or laser and chemical remover. Standardised photographs were taken before and after completion of the therapy. Quantitative digital image analysis (DIA) of colour changes within the RGB and HSV and L colour spaces was performed for pre- and postprocedural colour samples from eyebrows. The total change in all the parameters and the total colour distance (ΔD) were calculated. None of the colour parameters correlated with the number of laser sessions required to obtain a satisfactory effect of PMU removal. The receiver-operating characteristic (ROC) curve for the model estimating the probability of the need to use chemical remover (additionally to lasers) showed an acceptable value of area under the curve (AUC = 0.703) for H cut-off value of 15.3. The designed model based on digital image analysis (DIA) of eyebrow PMU colour may serve as a tool for planning a method of PMU removal. The H parameter over cut-off value indicates the need for application of additional chemical remover (laser therapy alone was not effective). However, more variables should be incorporated in the model to prove its clinical utility.