Defocused CO2 laser on equine skin: a histological examination.
BACKGROUND
No studies have been published on effects of treatment with a defocused beam carbon dioxide (CO2) laser on equine skin histology. A better understanding of this will help to define how lasers should be used, in order to reduce potential side effects.


OBJECTIVE
To describe the acute effects of different doses of defocused CO2 laser, ranging from therapeutic to surgical levels, on equine skin.


METHODS
Defocused CO2 laser was administered to the skin in the hamstrings (91 J/cm2), fetlock (137 J/cm2) and loin (450 J/cm2) areas of 13 Standardbred horses. The acute effects on skin histology were examined 90 min after the end of therapy.


RESULTS
Mild changes with focal spongiosis and subepidermal clefts were found after 91 J/cm2 irradiation and more severe changes with diffuse subepidermal clefts after the 137 J/cm2 dose. A homogeneous eosinophilic acellular zone of dermis and destruction of adnexal structures, and significant thinning of the epidermis was observed after the 450 J/cm2 dose.


CONCLUSIONS
The present study indicates acute dose-dependent changes in equine skin histology after laser treatment Severe tissue damage was induced using a 450 J/cm2 dose.


CONCLUSIONS
To reduce the potential side effects of defocused CO2 laser treatment, the laser parameters must be carefully evaluated. Caution should be taken if doses higher than 91 J/cm2 (16 W, 4 min, and 42 cm2) are used in irradiation of equine skin.
Bergh
A
A
Department of Anatomy and Physiology, Division of Pathology, Pharmacology and Toxicology, Swedish University of Agricultural Sciences, SE- 750 07 Uppsala, Sweden.
Ridderstråle
Y
Y
Ekman
S
S
D000818:Animals; D002245:Carbon Dioxide; D062109:Dermatologic Surgical Procedures; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006736:Horses / Q000601:surgery*; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D007834:Lasers / Q000009:adverse effects; D008297:Male; D012867:Skin / Q000473:pathology* / Q000528:radiation effects
D002245:Carbon Dioxide