Characterization of intraocular pressure pattern and changes of retinal ganglion cells in DBA2J glaucoma mice

AIM: To characterize the pattern of intraocular pressure(IOP) change and the deficit of retinal ganglion cells(RGCs) in DBA2 J, 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:IOPwasmonitoredwitharebound tonometer in WT C57bl/6 and DBA2 J mice from 3 to 15-month-old.Retinal function was evaluated by dark-adapted electroretinogram( ERG) in DBA2 J and WT mice of15-month-old. A dye(Neurobiotin) was applied to optic nerve stump to retrograde label RGCs. TO-PRO-3visualized 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 DBA2 J 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 at11-month-old and in 38% animals at 15-month-old. The RGCs density in DBA2 J mice started reducing by7-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-monthold DBA2 J mice. The amplitude of positive scotopic threshold response, and negative scotopic threshold response of ERG were significantly reduced in DBA2 J mice of 15-month-old than that in age-paired WT mice.·CONCLUSION: The present study found that DBA2 J mice display pathological and functional deficits of the retina that was not linearly correlated with IOP.