A U Bayer1, S E Brodie, T Mittag. 1. Department of Ophthalmology, Mount Sinai Medical Center, 1 Gustave L. Levy Place, New York, New York 10029, USA.
Abstract
PURPOSE: The aim of this study was to document the time-course of retinal dysfunction by pattern-electroretinography (PERG) in eyes of the DBA/2NNia substrain of mouse that develop an inherited angle-closure glaucoma. METHODS: Twelve DBA/2NNia mice and 12 control C57BL/6 J mice were studied by PERG recordings from 2 to 10 months of age. PERGs were recorded using different spatial and temporal frequencies. RESULTS: PERGs recorded with a temporal frequency of 7.5 Hz and a spatial frequency of 0.4 cycles/degree performed best to discriminate between DBA/2NNia mice and C57BL/6 J mice. When compared with normal C57BL/6 J mice, significant amplitude reductions of the PERG (Student's t-test; p < 0.01) were found in DBA/2NNia mice by 5 months of age and continued to decline as the animals aged. At beginning of follow-up, the mean PERG amplitude in DBA/2NNia mice was 2.3 +/- 0.5 microV. At 5 months of age, the mean PERG amplitude was reduced by 0.9 +/- 0.45 microV (paired t-test; p < 0.0001). CONCLUSION: Previously, a significant loss of retinal ganglion cells was found in the DBA/2NNia mouse substrain at 6-7 months of age. In the present study, we found decreases in PERG amplitudes, occurring from the age of 5 months onward. Similarities with the findings in human glaucoma indicate the relevance of this animal model for further glaucoma research.
PURPOSE: The aim of this study was to document the time-course of retinal dysfunction by pattern-electroretinography (PERG) in eyes of the DBA/2NNia substrain of mouse that develop an inherited angle-closure glaucoma. METHODS: Twelve DBA/2NNia mice and 12 control C57BL/6 J mice were studied by PERG recordings from 2 to 10 months of age. PERGs were recorded using different spatial and temporal frequencies. RESULTS: PERGs recorded with a temporal frequency of 7.5 Hz and a spatial frequency of 0.4 cycles/degree performed best to discriminate between DBA/2NNia mice and C57BL/6 J mice. When compared with normal C57BL/6 J mice, significant amplitude reductions of the PERG (Student's t-test; p < 0.01) were found in DBA/2NNia mice by 5 months of age and continued to decline as the animals aged. At beginning of follow-up, the mean PERG amplitude in DBA/2NNia mice was 2.3 +/- 0.5 microV. At 5 months of age, the mean PERG amplitude was reduced by 0.9 +/- 0.45 microV (paired t-test; p < 0.0001). CONCLUSION: Previously, a significant loss of retinal ganglion cells was found in the DBA/2NNia mouse substrain at 6-7 months of age. In the present study, we found decreases in PERG amplitudes, occurring from the age of 5 months onward. Similarities with the findings in humanglaucoma indicate the relevance of this animal model for further glaucoma research.