Patients with glaucoma may also have structural differences in their brains, specifically a decrease in the occipital pole surface area in both hemispheres that seemed to be tied to visual acuity, retinal nerve fiber layer thickness and other ocular parameters, a new study reports.

The cross-sectional prospective investigation included 30 glaucoma patients and 18 healthy volunteers. All participants underwent standard automated perimetry, spectral-domain OCT and MRI.

The researchers found significant differences between the surface area of the occipital pole in the left and right hemispheres of glaucoma patients (1253.9±149.3mm and 1910.5±309.4mm, respectively) compared with the control subjects (1341.9±129.8mm and 2089.1±164.2mm, respectively). However, no major changes were found in the lingual, calcarine, superior frontal and inferior frontal gyri of the glaucoma group and the healthy patients.

Of note: the surface areas of the occipital poles in the left and right hemispheres were significantly tied to perimetry mean deviation values, visual acuity, age and retinal nerve fiber layer thickness. The surface area of the occipital pole in the right hemisphere was also significantly correlated with visual field indices.

“Glaucoma patients presented a decreased occipital pole surface area in both hemispheres that independently correlated with functional and structural ocular parameters,” the researchers wrote in their paper. “These findings corroborate previous findings, which indicate that damage caused by glaucoma involves not only ocular structures but the entire visual pathway.”