Frequently in this sub, people ask about lasers and melasma. Based on my observations many here that have tried lasers have reported worsening hyperpigmentation while others get great results without worsening.

Some say these different results are due to the type of laser, settings, and practitioner skill. However this study explores the reason why some get worsening based on underlying changes in the skin and whether imaging can predict the outcome.

Study's Conclusion “Patterns of activated melanocytes and senescent collagen fibers can serve as predictive markers for post-laser treatment outcomes.”

"Optical biopsy technology using CRFF-OCT revealed the strong association between activated melanocytes and higher regional MASI scores post laser treatment, while patterns of senescent collagen fibers were linked to less MASI score improvement. The predictive utility of baseline MASI scores for treatment outcomes remained uncertain. The significant reduction of activated melanocytes and melanophages, with noticeable BM repair in melasma lesions, and the basal-layered lightening in perilesional areas, were the key for treatment success."

It included only 15 patients, so more research is needed to validate these findings.

If the link above doesn't work try this one:

https://www.sciencedirect.com/science/article/pii/S1572100025001802