title: Effect of anterior chamber cannulation and acute IOP elevation on retinal macrophages in the adult mouse.
abstract: OBJECTIVE
  To assess the retinal macrophage response to cannulation of the anterior chamber (AC) and acute elevation of intraocular pressure (IOP) in adult mice.
  
  
  METHODS
  Eyes from 12-month-old C57BL/6J WT mice were subject to IOP increase (50 mm Hg for 30 minutes) by direct cannulation of the AC. Fellow eyes were either cannulated without pressure increase or left untreated. Electroretinography was carried out prior to IOP elevation and 1 week later. Immunofluorescence staining was performed on frozen sections and retinal wholemounts 1 week after sham and IOP elevation. Eyes were assessed by epifluorescence and confocal microscopy and the density of vitreal hyalocytes and subretinal macrophages was calculated.
  
  
  RESULTS
  The density of hyalocytes and subretinal macrophages was significantly increased 1 week after IOP elevation and AC cannulation compared with naïve eyes. CD68 and MHC Class II expression was upregulated in both cannulated eyes and eyes with elevated IOP. Electroretinographic signals derived from retinal ganglion cells were significantly reduced in response to acute IOP elevation, but not in response to cannulation alone.
  
  
  CONCLUSIONS
  Cannulation of the AC causes an increase in hyalocyte density, microglial activation, and accumulation of macrophages in the subretinal space. These macrophage changes are similar to those observed in eyes subject to IOP elevation. Additional IOP elevation led to significant Müller cell activation, which was not evident after cannulation alone. These data highlight the importance of using appropriate controls in models of acute retinal injury.
authors.affiliation: Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia. Jelena.Kezic@monash.edu
authors.forename: Jelena M
authors.initials: JM
authors.lastname: Kezic
authors.forename: Vicki
authors.initials: V
authors.lastname: Chrysostomou
authors.forename: Ian A
authors.initials: IA
authors.lastname: Trounce
authors.forename: Paul G
authors.initials: PG
authors.lastname: McMenamin
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Crowston
mesh_terms: D000208:Acute Disease; D000818:Animals; D000867:Anterior Chamber / Q000503:physiopathology*; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D002404:Catheterization; D002452:Cell Count; D004596:Electroretinography; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000378:metabolism; D009798:Ocular Hypertension / Q000503:physiopathology*; D012160:Retina / Q000166:cytology*; D012165:Retinal Ganglion Cells / Q000502:physiology; D015854:Up-Regulation; D014822:Vitreous Body / Q000166:cytology; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000949:Histocompatibility Antigens Class II; C081026:CD68 protein, mouse; D000097382:CD68 Molecule