title: Longitudinal and simultaneous imaging of retinal ganglion cells and inner retinal layers in a mouse model of glaucoma induced by N-methyl-D-aspartate.
abstract: OBJECTIVE
  To investigate the longitudinal profile of N-methyl-D-aspartate (NMDA) injection-induced damage in retinal ganglion cells (RGCs) by imaging retinal Thy 1-cyan fluorescent protein (CFP) expression and inner retinal layers using a custom-made imaging device containing short-wavelength confocal scanning laser ophthalmoscope (scSLO) and speckle noise-reduced spectral-domain optical coherence tomography (SD-OCT).
  
  
  METHODS
  Simultaneous scSLO and SD-OCT examinations were performed in Thy 1-CFP mice injected with NMDA (1-20 nanomoles). CFP-expressing RGCs were counted using scSLO images. Ganglion cell complex (GCC: retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer) thickness around the optic disc was measured in SD-OCT images.
  
  
  RESULTS
  The RGCs rapidly decreased 1 day after NMDA injection in a dose-dependent manner (65.3%, 71.7%, 49.5%, and 27.1% of the preinjection level, 2, 5, 10, and 20 nanomoles, respectively) and continued to decrease slightly (to 53.7%, 44.1%, 28.3%, and 20.2% of the preinjection level on days 14, 2, 5, 10, and 20 nanomoles, respectively). In contrast, dose-dependent reduction of GCC thickness was first detected 4 days after injection. The thickness further decreased to 84.6%, 75.7%, 76.5%, and 71.4% of the preinjection level on day 14 (2, 5, 10, and 20 nanomoles, respectively).
  
  
  CONCLUSIONS
  NMDA-induced RGC damage is characterized by rapid RGCs loss followed by gradual reduction in GCC thickness. Simultaneous imaging of CFP expression in the RGCs and inner retinal layers provides a sensitive, reliable, and new method for longitudinal evaluation of progressive RGC damage in experimental models of glaucoma.
authors: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors: Noriko
authors: N
authors: Nakano
authors: Hanako Ohashi
authors: HO
authors: Ikeda
authors: Masanori
authors: M
authors: Hangai
authors: Yuki
authors: Y
authors: Muraoka
authors: Yoshinobu
authors: Y
authors: Toda
authors: Akira
authors: A
authors: Kakizuka
authors: Nagahisa
authors: N
authors: Yoshimura
mesh_terms: D025042:Amacrine Cells / Q000473:pathology; D000818:Animals; D004195:Disease Models, Animal; D018450:Disease Progression; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D005901:Glaucoma / Q000139:chemically induced / Q000473:pathology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D008137:Longitudinal Studies; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D016202:N-Methylaspartate / Q000494:pharmacology*; D009887:Ophthalmoscopy / Q000379:methods / Q000592:standards; D009898:Optic Disk / Q000473:pathology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods* / Q000592:standards
chemical_list: C485182:Cyan Fluorescent Protein; D018690:Excitatory Amino Acid Agonists; D049452:Green Fluorescent Proteins; D016202:N-Methylaspartate