title: Characterization of intraocular pressure pattern and changes of retinal ganglion cells in DBA2J glaucoma mice.
abstract: OBJECTIVE
  To characterize the pattern of intraocular pressure (IOP) change and the deficit of retinal ganglion cells (RGCs) in DBA2J, which is most well-characterized chronic glaucoma mouse model and wild type (WT) C57bl/6 mice, and to study the relationship between IOP change and RGCs deficit.
  
  
  METHODS
  IOP was monitored with a rebound tonometer in WT C57bl/6 and DBA2J mice from 3 to 15-month-old. Retinal function was evaluated by dark-adapted electroretinogram (ERG) in DBA2J and WT mice of 15-month-old. A dye (Neurobiotin) was applied to optic nerve stump to retrograde label RGCs. TO-PRO-3 visualized all nuclei of cells in the RGC layer.
  
  
  RESULTS
  The IOP in WT mice was 9.03±0.6 mm Hg on average and did not increase significantly as aging. The IOP in DBA2J mice, arranging from 7.2 to 28 mm Hg, was increasing significantly as aging, and it was normal at 3-month-old compared with WT mice, slightly increased from 7-month-old and increased in 50% animals at 11-month-old and in 38% animals at 15-month-old. The RGCs density in DBA2J mice started reducing by 7-month-old, continuously decreased until reached about 20% of RGC in WT retina by 15-month-old. RGC density was not linearly correlated with IOP in 15-month-old DBA2J mice. The amplitude of positive scotopic threshold response, and negative scotopic threshold response of ERG were significantly reduced in DBA2J mice of 15-month-old than that in age-paired WT mice.
  
  
  CONCLUSIONS
  The present study found that DBA2J mice display pathological and functional deficits of the retina that was not linearly correlated with IOP.
authors.affiliation: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Dong
keywords: glaucoma; intraocular pressure; mouse; retina; retinal ganglion cell