Abstract
Purpose :
Glaucoma causes widespread damage to central visual pathway. Attempts are currently being made to detect glaucomatous degeneration in the brain with magnetic resonance imaging (MRI) of the visual pathway. In this study, we investigated whether MRI could reveal glaucomatous changes in specific regions of the primary visual cortex.
Methods :
The participants were 13 healthy volunteers (55.6 ± 9.1 years old, male: female = 6: 7), and 31 open-angle glaucoma (OAG) patients (57.4 ± 8.1 years old, male: female = 9: 22, MD value: 11.5 ± 7.4 dB). MRI (Achieva 3.0T, Philips) was used to create 3DT1-weighted images. Anatomical standardization of the images was performed with SPM12. Gray matter volume maps were created, reflecting the local volume of gray matter in each voxel. The left and right sides of the visual cortex were each divided vertically, into regions above and below the calcar avis, and horizontally, into ventral, middle, and dorsal regions, for an overall total of 12 regions. We calculated gray matter volume in each region and compared the results in the normal and glaucoma groups, with the Wilcoxon singled-rank test.
Results :
On the right side of the primary visual cortex, the two groups showed a significant difference in the lower ventral region (normal: 0.37 ± 0.07, vs. glaucoma: 0.34 ± 0.05, p = 0.034) and the upper ventral region (normal: 0.37 ± 0.05, vs. glaucoma: 0.32 ± 0.05, p = 0.006). On the left side of the cortex, the two groups showed a difference in the upper middle region (normal: 0.53 ± 0.07, glaucoma: 0.45 ± 0.07, p = 0.005).
Conclusions :
This study found that glaucoma patients had significantly reduced gray matter volume in specific regions of the primary visual cortex: the upper and lower ventral regions of the right side, and the upper middle region of the left side. Thus, glaucoma may cause characteristic changes in the primary visual cortex, suggesting that regional evaluation of the primary visual cortex might be useful as an objective method of glaucoma diagnosis.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.