ISSN:
1435-604X
Keywords:
Copper vapour laser
;
Electron microscopy
;
Illumination time
;
Numerical modelling
;
Optimal treatment
;
Port-wine stain
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Physics
,
Technology
Notes:
Abstract This paper reports the electron microscopy results obtained from two patients who were treated with 5 W of yellow (578 nm) light from a copper vapour laser with an illumination time of 3.6 ms and a 0.3 mm spot diameter. The endpoint of treatment was transient blanching. Following treatment, erythema was observed. There was minimal damage to the epidermis and non-vascular tissue such as the nerve fibres. There was severe damage to the endothelial cells of the ectatic vessels. Twenty-four hours after treatment, platelet activation and collagen were present, indicating that these vessels were no longer viable. Theoretical calculations are used to determine the flow of heat within and away from a 50μm diameter vessel. From this, heating of the entire vessel is shown to occur with illumination times of 4 ms, with minimal heating of the non-vascular tissue. Shorter illuminations do not heat the entire vessel, while the use of longer illumination times will cause excessive damage to the surrounding non-vascular tissue. Illumination times close to 4 ms must be regarded as optimal.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02150846
Permalink
