title: A histological analysis of the protective effect of ischemic preconditioning in the rat retina.
abstract: OBJECTIVE
  Ischemic preconditioning (IP) protects the retina from the damaging effect of subsequent ischemia in vivo. We aimed to investigate the histological alterations induced by the protective effect of IP to the retina.
  
  
  METHODS
  The eyes of the rats were rendered ischemic by intra-ocular pressure (IOP) elevation. IP procedure consisted of producing ischemia for 5 minutes. Sham operation was similar to IP procedure except the pressure elevation. The operational eyes of sham and IP group underwent 60 minutes of ischemia 24 hours after the first procedure. The eyes contralateral to the experimental eyes made up the control group. The eyes were histologically analysed one week after the ischemia.
  
  
  RESULTS
  The total retinal thickness of the sham group was significantly less than total retinal thickness of the control group (p < 0.001). There was not a significant difference between control and IP group regarding the total retinal thickness (p > 0.05). The thickness of the inner retinal layers of the sham group were significantly less than corresponding retinal layers of the control group (p < 0.001). The inner plexiform layer (IPL) and inner nuclear layer (INL) thickness values of the sham group were significantly less than same layers of the IP group (p < 0.001). Ganglion cell layer (GCL) thickness of the IP group was significantly less than GCL thickness of the control group (p < 0.001). IPL thickness of the IP group was significantly less than that of control group's (p < 0.05). The GCL and total retinal thickness of the IP group were significantly more than thickness of the corresponding layers of the sham group (p < 0.05).
  
  
  CONCLUSIONS
  IP considerably protects inner retinal layers from subsequent ischemic damage in a high IOP ischemic model. This endogenous process could further be utilized to tailor specific neuroprotective strategies for retinal cells.
authors.affiliation: Department of Ophthalmology, Celar Bayar University, Manisa, Turkey. abaris@superonline.com
authors.forename: Ahmet Baris
authors.initials: AB
authors.lastname: Toprak
authors.forename: Kemal
authors.initials: K
authors.lastname: Ozbilgin
authors.forename: Verda
authors.initials: V
authors.lastname: Toprak
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Tuglu
authors.forename: Cenap
authors.initials: C
authors.lastname: Guler
mesh_terms: D000818:Animals; D035061:Control Groups; D019194:Ischemic Preconditioning; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000473:pathology* / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012171:Retinal Vessels