Digital Measurement of Melasma: Towards Eliminating Subjectivity from Treatment Evaluation

The document presents a study on a digital measurement system for melasma, aiming to reduce subjectivity in treatment evaluation. The traditional Melasma Area and Severity Index (MASI) relies on subjective assessments by doctors, which can be inconsistent. The proposed digital system uses cross-polarization to overcome skin reflectivity and photographs the patient's face from multiple angles. A computer algorithm then analyzes the images, using calibration patches and a hidden Markov model to classify pixels as affected or unaffected by melasma. In a preliminary validation on a single patient, the system correctly identified 92% of the affected area and had a 5% false-positive rate for unaffected areas. The study concludes that further development is needed to integrate multiple views into a single model and to automate facial feature detection, with future work to evaluate the system on a larger patient group. No commercial support was identified for this study.