title: The protective effect of prophylactic ozone administration against retinal ischemia-reperfusion injury.
abstract: BACKGROUND
  Retinal ischemia-reperfusion (IR) injury is associated with many ocular diseases. Retinal IR injury leads to the death of retinal ganglion cells (RGCs), loss of retinal function and ultimately vision loss. The aim of this study was to show the protective effects of prophylactic ozone administration against retinal IR injury.
  
  
  METHODS
  A sham group (S) (n = 7) was administered physiological saline (PS) intraperitoneally (i.p.) for 7 d. An ischemia reperfusion (IR) group (n = 7) was subjected to retinal ischemia followed by reperfusion for 2 h. An ozone group (O) (n = 7) was administered 1 mg/kg of ozone i.p. for 7 d. In the ozone + IR (O + IR) group (n = 7), 1 mg/kg of ozone was administered i.p. for 7 d before the IR procedure and at 8 d, the IR injury was created (as in IR group). The rats were anesthetized after second hour of reperfusion and their intracardiac blood was drawn completely and they were sacrificed. Blood samples were sent to a laboratory for analysis of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), total oxidant score (TOS) and total antioxidant capacity (TAC). The degree of retinal injury was evaluated according to changes in retinal cells and necrotic and apoptotic cells using the TUNEL method. Data were evaluated statistically with the Kruskal-Wallis test.
  
  
  RESULTS
  The number of RGCs and the inner retinal thickness were significantly decreased after ischemia, and treatment with ozone significantly inhibited retinal ischemic injury. In the IR group, the degree of retinal injury was found to be the highest. In the O + IR group, retinal injury was found to be decreased in comparison to the IR group. In the ozone group without retinal IR injury, the retinal injury score was the lowest. The differences in the antioxidant parameters SOD, GSH-Px and TAC were increased in the ozone group and the lowest in the IR group. The oxidant parameters MDA and TOS were found to be the highest in the IR group and decreased in the ozone group.
  
  
  CONCLUSIONS
  IR injury is also positively correlated with the degree of early apoptosis. This study demonstrated that ozone can attenuate subsequent ischemic damage in the rat retina through triggering the increase of the antioxidant capacity.
authors.affiliation: a Department of Ophthalmology.
authors.forename: Ali
authors.initials: A
authors.lastname: Kal
authors.affiliation: b Department of Nephrology , and.
authors.forename: Oznur
authors.initials: O
authors.lastname: Kal
authors.affiliation: c Department of Pediatric Surgery , Baskent University, Medical Faculty , Konya , Turkey.
authors.forename: Ishak
authors.initials: I
authors.lastname: Akillioglu
authors.affiliation: d Department of Pathology.
authors.forename: Esin
authors.initials: E
authors.lastname: Celik
authors.affiliation: e Department of Histology and Embryology.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Yilmaz
authors.affiliation: f Department of Ophthalmology.
authors.forename: Saban
authors.initials: S
authors.lastname: Gonul
authors.affiliation: g Department of Histology and Embryology , and.
authors.forename: Merve
authors.initials: M
authors.lastname: Solmaz
authors.affiliation: h Department of Anesthesiology and Reanimation , Medical Faculty, Selcuk University , Konya , Turkey.
authors.forename: Ozkan
authors.initials: O
authors.lastname: Onal
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000097:blood; D008315:Malondialdehyde / Q000097:blood; D016877:Oxidants / Q000627:therapeutic use*; D010126:Ozone / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000097:blood / Q000473:pathology / Q000517:prevention & control*; D012160:Retina / Q000187:drug effects / Q000473:pathology; D012164:Retinal Diseases / Q000097:blood / Q000473:pathology / Q000517:prevention & control*; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D016877:Oxidants; D008315:Malondialdehyde; D010126:Ozone; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase
keywords: Antioxidant; apoptosis; ischemia reperfusion injury; ozone; retina