Pattern-electroretinographic changes in theDBA/2NNia mouse-model of angle-closure glaucoma (pilot study)

Purpose. The aim of this study was to document the time-course of retinal d ysfunction by pattern-electroretinography (PERG) in eyes of the DBA/2NNia s ubstrain of mouse that develop an inherited angle-closure glaucoma. Methods. Twelve DBA/2NNia mice and 12 control C57BL/6 J mice were studied b y PERG recordings from 2 to 10 months of age. PERGs were recorded using dif ferent spatial and temporal frequencies. Results. PERGs recorded with a temporal frequency of 7.5 Hz and a spatial f requency of 0.4 cycles/degree performed best to discriminate between DBA/2N Nia mice and C57BL/6 J mice. When compared with normal C57 BL/6 J mice, sig nificant amplitude reductions of the PERG (Student's t-test; p<0.01) were f ound in DBA/2NNia mice by 5 months of age and continued to decline as the a nimals aged. At beginning of follow-up, the mean PERG amplitude in DBA/2NNi a mice was 2.3<plus/minus>0.5 muV. At 5 months of age,the mean PERG amplitu de was reduced by 0.9 +/-0.45 muV (paired t-test; p<0.0001). Conclusion. Previously,a significant loss of retinal ganglion cells was fou nd in the DBA/2NNia mouse substrain at 6-7 months of age. In the present st udy,we found decreases in PERG amplitudes, occurring from the age of 5 mont hs onward. Similarities with the findings in human glaucoma indicate the re levance of this animal model for further glaucoma research.