Comparison of 585 and 595 nm laser-induced vascular response of normal in vivo human skin
Article first published online: 9 FEB 2005
Copyright © 2005 Wiley-Liss, Inc.
Lasers in Surgery and Medicine
Volume 36, Issue 2, pages 117–123, February 2005
How to Cite
Pikkula, B. M., Chang, D. W., Nelson, J. S. and Anvari, B. (2005), Comparison of 585 and 595 nm laser-induced vascular response of normal in vivo human skin. Lasers Surg. Med., 36: 117–123. doi: 10.1002/lsm.20147
- Issue published online: 9 FEB 2005
- Article first published online: 9 FEB 2005
- Manuscript Accepted: 29 DEC 2004
- Institute of Arthritis, Musculoskeletal, and Skin Disease at NIH. Grant Numbers: AR47996, AR47751
- Texas Higher Education Coordinating Board
- Candela Corporation
- bathochromic shift;
- blood coagulation;
- laser therapy;
- port wine stain;
- selective photothermolysis
Background and Objectives
Two wavelengths, 585 and 595 nm, are currently common options for treating vascular malformations such as port-wine stains (PWS). Controversy exists as to which wavelength induces greater photothermal damage to the blood vessels and subsequent resolution of the malformations.
Study Design/Materials and Methods
We irradiated normal, human skin in vivo at 585 and 595 nm wavelengths using fluences of 10–30 J/cm2 with a 1.5 millisecond laser pulse. The level of purpura, total vascular damage, maximum coagulation depth (MCD), and perivascular damage were quantified by gross observation and histological analysis.
Results demonstrated that 585 nm light caused greater purpura, vascular damage, maximum coagulation depth, and perivascular damage than 595 nm. Purpura showed a positive correlation with total vascular damage to a certain extent beyond which the total vascular damage did not change. For equivalent purpura, 585 and 595 nm produced no statistically significant difference in vascular damage. The difference in the laser-induced vascular damage between 585 and 595 nm, although statistically significant, was no more than 50%.
The bathochromic (red) shift and formation of met-hemoglobin, which reduces the 585 nm light absorption and increases that of 595 nm compared to native oxy-hemoglobin, play a considerable role in creating more parity in vascular damage between the two wavelengths than would be expected based on their respective “native” absorption coefficients alone. Lasers Surg. Med. 36:117–123, 2005. © 2005 Wiley-Liss, Inc.