Structure-function correlations in Retinitis Pigmentosa patients with partially preserved vision: a voxel-based morphometry study

Retinitis Pigmentosa is a group of hereditary retinal dystrophy disorders associated with progressive peripheral visual field loss. The impact of this retinal loss in cortical gray matter volume has not been addressed before in Retinitis Pigmentosa patients with low vision. Voxel-based morphometry was applied to study whole brain gray matter volume changes in 27 Retinitis Pigmentosa patients with partially preserved vision and 38 age- and gender-matched normally sighted controls to determine whether peripheral visual loss can lead to changes in gray matter volume. We found significant reductions in gray matter volume that were restricted to the occipital cortex of patients. The anteromedial pattern of reduced gray matter volume in visual primary and association cortices was significantly correlated with the extent of the peripheral visual field deficit in this cohort. Moreover, this pattern was found to be associated with the extent of visual field loss. In summary, we found specific visual cortical gray matter loss in Retinitis Pigmentosa patients associated with their visual function profile. The spatial pattern of gray matter loss is consistent with disuse-driven neuronal atrophy which may have clinical implications for disease management, including prosthetic restoration strategies.