Model-guided non-whitening endpoint for 755-nm picosecond laser treatment of acquired bilateral nevus of Ota-like macules (ABNOM) in pigmented skin: A randomized split-face trial.

Abstract

Post-inflammatory hyperpigmentation (PIH) is a major concern in laser treatment of dermal melanocytosis in pigmented skin, particularly when immediate whitening is used as the therapeutic endpoint. To compare a computational model-guided non-whitening endpoint with the conventional whitening endpoint for treating acquired bilateral nevus of Ota-like macules (ABNOM) using a 755-nm picosecond alexandrite laser. In this prospective, randomized, evaluator-blinded, split-face trial, 30 Asian patients (Fitzpatrick skin types III-V) underwent 3 sessions at 6-month intervals. One facial side received a larger spot size and lower fluence designed by a melanosome-disruption threshold fluence model to achieve a nonwhitening endpoint. The contralateral side received a smaller spot size and higher fluence to achieve immediate whitening. Both endpoints achieved comparable and high clearance after 3 sessions (Global Aesthetic Improvement Scale >3.85/4). However, the whitening endpoint resulted in higher rates of PIH (22.6% vs 4.8%, P < .05) and scabbing (61.9% vs 9.5%, P < .05). Patient satisfaction was high for both approaches, with 68% preferring the non-whitening endpoint. Single-center study with limited inclusion of Fitzpatrick skin types III-V. The model-guided nonwhitening endpoint achieved comparable efficacy with less PIH and scabbing, supporting a safer strategy for ABNOM in pigmented skin.