title: Rat chronic glaucoma model induced by intracameral injection of microbeads suspended in sodium sulfate-sodium hyaluronate.
abstract: OBJECTIVE
  To establish a rat glaucoma model with chronic intraocular pressure (IOP) elevation induced by microbeads suspended in sodium sulfate-sodium hyaluronate.
  
  
  METHODS
  Chronic elevation of IOP was induced unilaterally by injecting polystyrene microbeads, suspended in 4 % sodium sulfate and 3 % sodium hyaluronate, into the anterior chamber. The microbead suspension was injected through either the clear corneal (CC) or sclerocorneal (SC) tunnel. IOP changes were monitored up to 8 weeks after injection. The loss of retinal ganglion cells (RGCs) was assessed using fluorogold retrograde labeling of RGCs. RGC axons were evaluated by immunohistochemistry and immunoblotting.
  
  
  RESULTS
  The resulting IOP elevation was maintained up to 3 weeks after the intracameral injection of microbeads through the CC route and up to 4 weeks after injection through the SC route. The density of RGCs was significantly reduced at 4 weeks after injection, with the SC route leading to more RGC loss than the CC route (p = 0.037). The neurofilament immunoreactivity and protein levels in the optic nerve were also significantly reduced at 4 weeks after injection. Some eyes in the SC route cohort received re-injection of the microbead suspension at 4 weeks after the initial injection, which led to an elevated IOP more than 8 weeks after the initial injection, and eventually a 27.5 % loss of RGC density compared with the control eyes.
  
  
  CONCLUSIONS
  The intracameral injection of microbeads suspended in hyaluronate effectively produced chronic IOP elevation and subsequent RGC degeneration in rat eyes. The sclerocorneal tunnel approach yielded a longer period of IOP elevation than the clear corneal approach. Our modified microbead injection offers a reliable high-pressure glaucoma model.
authors.affiliation: Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: Akiyasu
authors.initials: A
authors.lastname: Kanamori
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakamura
authors.forename: Akira
authors.initials: A
authors.lastname: Negi
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000187:drug effects*; D001369:Axons / Q000473:pathology; D002908:Chronic Disease; D004195:Disease Models, Animal; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D005901:Glaucoma / Q000175:diagnosis / Q000209:etiology*; D006820:Hyaluronic Acid / Q000737:chemistry; D015151:Immunoblotting; D056965:Injections, Intraocular; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008863:Microspheres; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000473:pathology; D013266:Stilbamidines; D013431:Sulfates / Q000737:chemistry; D013535:Suspensions / Q000009:adverse effects* / Q000737:chemistry; D014065:Tonometry, Ocular
chemical_list: C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D005456:Fluorescent Dyes; D013266:Stilbamidines; D013431:Sulfates; D013535:Suspensions; C012036:sodium sulfate; D006820:Hyaluronic Acid