Abstract
Purpose: :
To determine if structural brain changes are correlated with visual function in glaucoma patients.
Methods: :
11 glaucoma patients with varying levels of clinical severity and 11 age-, race- and gender-matched controls underwent T-1 weighted MRI brain scans. Exclusion criteria included neurological disease, another disorder which could affect the visual field, and score of less than 25 on the mini-mental status exam. The brain scans were analyzed with tensor-based morphometry to identify volumetric differences in 22 areas of cerebral cortex among the glaucoma patients and controls. These volumes were correlated with clinical measures of visual function including mean defect (MD) and peripheral vision sub-scale of the VFQ-25. Two-tailed p-values of Pearson correlation coefficients were calculated to determine the significance of these correlations.
Results: :
In glaucoma patients, the absolute volumes of the right and left lateral occipitotemporal gyri were directly correlated with peripheral vision sub-scale scores of the VFQ-25 (r=0.63, p=0.04 and r=0.63, p=0.04, respectively). The absolute volume of the right lateral occipitotemporal gyrus was directly correlated with the MD of both the right eye (r=0.65, p= 0.03) and the left eye (r=0.63, p=0.04). The relative volume of the right inferior temporal gyrus was correlated with the MD of the left eye (r=0.64, p=0.04). The absolute volumes of the right inferior temporal gyrus and the right lateral occipitotemporal gyrus were correlated with the average of the MDs of the two eyes (r=0.69, p=0.02 and r=0.69, p=0.02, respectively). No correlations were found between the brain volumes of the controls and the clinical parameters studied. The average volumes of these cortical areas did not differ significantly between the glaucoma and control groups. Those areas that did differ between the two groups had no significant association with the clinical parameters studied. There were significant negative correlations between increasing age and brain volume in both groups, however there were no significant correlations between age and any clinical parameter in either group.
Conclusions: :
These data suggest intriguing associations which deserve further study.
Clinical Trial: :
http://www.clinicaltrials.gov NCT01303939
Keywords: visual cortex • clinical (human) or epidemiologic studies: natural history