Direct intraindividual comparison of wound healing after fractional picosecond laser-induced optical breakdown at 0.2 versus 0.3 J/cm² under topical postprocedural care: a prospective intraindividual case series

Abstract

This prospective intraindividual case series evaluated early visible wound healing after fractional 1064 nm picosecond laser-induced optical breakdown (LIOB) at two intermediate fluence settings under standardized topical postprocedural care. Ten adult volunteers with Fitzpatrick skin type II underwent paired treatment of volar forearm fields at 0.2 and 0.3 J/cm². Six predefined topical preparations were applied to adjacent areas: Bepanthen wound and healing ointment, Medigel, Laser doctor cream, SkinCeuticals RGN 6, Teoxane post procedure, and Vichy collagen specialist 16 serum. Dermatoscopic images were obtained on days 1, 4, and 8 using non-polarized, polarized, and 405 nm illumination and were rated by two blinded dermatologists on a seven item 5-point scale. The complete case-series dataset included 10 participants, 6 products, 2 fluence levels, and 3 time points. Across all 18 product-timepoint composite comparisons, scores were higher at 0.3 than at 0.2 J/cm², with median paired differences of 1.0 to 3.5 points. After Holm adjustment, the day 4 comparison for Vichy collagen specialist 16 serum remained significant. Item-level signals mainly involved crusting/scabbing, surface texture, vascularization, irritation, and overall assessment, while surface level remained unchanged. Both fluence settings showed progressive visible improvement by day 8. This case series suggests that a moderate increase from 0.2 to 0.3 J/cm² increases short-term visible post-LIOB reaction without evidence of delayed early healing in this small Fitzpatrick type II cohort.