title: The effects of variable pulse width of Er:YAG laser on facial skin.
abstract: BACKGROUND
  The use of CO2 and Er:YAG lasers for resurfacing has increased significantly in the past few years. Er:YAG laser causes pinpoint bleeding during and after treatment with a typical pulse width of 250 microsec. A longer pulse of Er:YAG laser can potentially coagulate dermal blood vessels and increase the residual thermal damage (RTD).
  
  
  OBJECTIVE
  To evaluate the effects of various pulse durations of Er:YAG laser on the depth of RTD and bleeding.
  
  
  METHODS
  The preauricular skin of a volunteer was exposed to Er:YAG laser at 250-, 350-, and 700-microsec pulse durations, with a fluence of 5 J/cm2. The number of passes varied between 6 and 16. The treated skin was excised and a histologic evaluation was done.
  
  
  RESULTS
  The maximum depth of RTD was 50 microm and there was decreased bleeding with a 700-microsec pulse duration.
  
  
  CONCLUSIONS
  The increased pulse duration of Er:YAG laser of 700 micros does not increase the maximum reported RTD and therefore would not change the recovery time and may have a beneficial effect on hemostasis.
authors: The Skin and Laser Surgery Center of New England, 777 Concord Ave., Suite 206, Cambridge, MA 02138, USA. skinlaser@aol.com
authors: K A
authors: KA
authors: Khatri
mesh_terms: D062109:Dermatologic Surgical Procedures; D005145:Face; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D008875:Middle Aged; D012867:Skin / Q000473:pathology*