Border Sharpness Index: A Proof-of-Concept Approach for Quantifying Pigmentary Transition Morphology in Vitiligo

Area of Science:

• Dermatology
• Medical Imaging
• Computational Biology

Background:

• Traditional vitiligo assessment relies on lesion extent and activity scores like VASI and VIDA.
• Objective characterization of vitiligo lesion border morphology is underexplored.
• Pigmentary transition zones are key indicators of disease stability.

Purpose of the Study:

• To explore an image-analysis approach for objective quantitative characterization of vitiligo pigmentary transition morphology.
• To introduce a novel Border Sharpness Index (BSI) for quantifying border characteristics.
• To assess the utility of grayscale intensity profiling in vitiligo assessment.

Main Methods:

• Utilized Wood's lamp images from a vitiligo patient.
• Applied grayscale intensity profiling using Fiji/ImageJ software.
• Developed and applied a Border Sharpness Index (BSI) integrating intensity variation and transition distance.

Main Results:

• Grayscale intensity profiling revealed reproducible directional transitions at lesional borders.
• Healthy skin showed minimal fluctuation, while depigmented areas had oscillatory patterns.
• The proposed BSI quantitatively described pigmentary transition morphology.

Conclusions:

• Grayscale intensity profiling can objectively characterize the spatial architecture of vitiligo's pigmentary transition zone.
• The BSI offers a potential quantitative descriptor for vitiligo morphology.
• This methodology introduces a new quantitative dimension for vitiligo assessment, complementing existing methods.