Laser Hair Removal and the Influence of Spot Size

Abstract

Introduction:

The purpose of this study is to critically and prospectively examine the role of spot size in laser hair treatment when all other variables are kept the same.

Materials and Methods:

Fifteen women aged 17 to 37 years were enrolled in this prospective study. Laser hair removal was performed in the axillae, using a 755-nm alexandrite laser with an 8-mm and a 12-mm spot size. Each patient underwent a minimum of 3 and a maximum of 4 treatment sessions spaced 6 weeks apart.

Results:

Results 6 months after the last treatment were quite good (83% reduction) with the 12-mm spot size but far less impressive (56% reduction) with the 8-mm spot size. In other words, treatment with the 8-mm spot size resulted, on average, in 2.6 times more residual hairs than treatment with the 12-mm spot size.

Discussion:

Fluences in the range of 30 to 40 J/cm² with spot sizes of 12 mm or greater are highly effective at achieving long-term hair reduction with a 3-ms-pulse-width 755-nm Alexandrite laser.