Time Course of Age-dependent Changes in Intraocular Pressure and Retinal Ganglion Cell Death in DBA/2J Mouse

Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.

Purpose ： To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure （IOP） and retinal ganglion cells （RGCs） numbers in mice of various ages. Methods ： A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results： The baseline IOP for DBA/2J mice at 7 weeks was （16.6 ± 1.2）mm Hg. Then IOP increased extend to 12 months, with the peak of （25.2±1.2）mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age （P=0.006）, when the loss was proportionally higher in peripheral regions （ P〈0.05 ）. Conclusion： The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma. Eye Science 2006;22：184-189.