title: Corneal aldehyde dehydrogenase and glutathione S-transferase activity after excimer laser keratectomy in guinea pigs.
abstract: BACKGROUND
  The free radical balance of the eye may be changed by excimer laser keratectomy. Previous studies have demonstrated that excimer laser keratectomy increases the corneal temperature, decreases the superoxide dismutase activity of the aqueous, and induces lipid peroxidation in the superficial corneal stroma. Aldehyde dehydrogenase (ALDH) and glutathione S-transferase (GST) are known to play an important role in corneal metabolism, particularly in detoxification of aldehydes, which are generated from free radical reactions.
  
  
  METHODS
  In three groups of guinea pigs mechanical corneal de-epithelialisation was performed in group I, superficial corneal photoablation in group II, and deep corneal photoablation in group III, and the corneal ALDH and GST activities measured after 48 hours.
  
  
  RESULTS
  The mean ALDH and GST activities of group I and II showed no differences compared with the controls (p > 0.05). The corneal ALDH activities were found to be significantly decreased (p < 0.05) and GST activities increased (p < 0.05) in group III.
  
  
  CONCLUSIONS
  These results suggest that excimer laser treatment of high myopia may change the ALDH and GST activities, metabolism, and free radical balance of the cornea.
authors.affiliation: Gazi University Medical School, Ankara, Turkey.
authors.forename: K
authors.initials: K
authors.lastname: Bilgihan
authors.forename: A
authors.initials: A
authors.lastname: Bilgihan
authors.forename: B
authors.initials: B
authors.lastname: Hasanreisoğlu
authors.forename: N
authors.initials: N
authors.lastname: Turkozkan
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000032:analysis*; D000818:Animals; D003315:Cornea / Q000201:enzymology* / Q000528:radiation effects; D005131:Eye Injuries / Q000201:enzymology / Q000209:etiology; D005982:Glutathione Transferase / Q000032:analysis*; D006168:Guinea Pigs; D054018:Lasers, Excimer; D018903:Photorefractive Keratectomy / Q000009:adverse effects*
chemical_list: D000444:Aldehyde Dehydrogenase; D005982:Glutathione Transferase