Visual Tract Degradation in Bilateral Normal-Tension Glaucoma—Cortical Thickness Maps and Volumetric Study of Visual Pathway Areas

Abstract

The aim of the study was to evaluate changes in the central visual pathways during the early and advanced stages of bilateral normal-tension glaucoma (NTG). Methods: The studied groups constituted patients with bilateral normal-tension glaucoma of the same stage (n = 45) and age-matched healthy volunteers (n = 17). All patients underwent ophthalmic examination and examination on a 1.5 Tesla Magnetic Resonance Scanner (Optima 360, GE Healthcare). Volume and cortical thickness analyses were performed using the open-source automated software package FreeSurfer. Results: There was a significant difference in lateral geniculate nuclei volume between the control and advanced glaucoma groups in the right hemisphere (p = 0.03) and in the left hemisphere between the early and advanced glaucoma patients (p = 0.026). The optic chiasm volume differed significantly between the control and advanced NTG groups (p = 0.0003) and between early and advanced glaucoma patients (p = 0.004). Mean cortical thickness analysis revealed a significant increase in values in the advanced glaucoma group in the right Brodmann area 17 (BA17) (p = 0.007) and right BA18 (p = 0.049) as compared to early NTG. In the left BA18 area, the mean thickness of the cortex in the early glaucoma group was significantly lower than in the control group (p = 0.03). Conclusions: The increase in the grey matter thickness in the V1 region with more-advanced glaucoma stages may reflect compensatory hypertrophy. Additionally, the regions of the brain early affected during glaucoma with reduced thickness were the right lateral occipital gyrus and left lingual gyrus. The most prominent change during the course of glaucoma was the increase in grey matter thickness in the right cuneus.

Machine learning analysis reveals abnormal functional network hubs in the primary angle-closure glaucoma patients

“… Fujishiro et al (2022) reported that ocular hypertension could lead to reduced cytochrome oxidase expression in the visual cortex. Pankowska et al (2022) found that normal-tension glaucoma patients had reduced thickness in the right lateral occipital gyrus and left lingual gyrus. Consistent with these findings, we observed significantly lower DC values in the right calcarine sulcus in PACG patients, which suggested abnormal functional connectivity within the visual network.…”

Altered dynamic functional connectivity in the primary visual cortex in patients with primary angle-closure glaucoma

“… Nuzzi et al (2018) demonstrated that patients with glaucoma showed abnormal FC changes in the visual pathway. In addition, Pankowska et al (2022) reported that the patients with advanced glaucoma showed an increase in the gray matter thickness in the V1 region. Meanwhile, early glaucoma was associated with reduced thickness in the right lateral occipital gyrus and the left lingual gyrus ( Pankowska et al, 2022 ).…”

“…In addition, Pankowska et al (2022) reported that the patients with advanced glaucoma showed an increase in the gray matter thickness in the V1 region. Meanwhile, early glaucoma was associated with reduced thickness in the right lateral occipital gyrus and the left lingual gyrus ( Pankowska et al, 2022 ). Haykal et al (2022) reported that patients with primary open-angle glaucoma (POAG) showed a loss of both axonal coherence and density in the pregeniculate visual pathways, while the postgeniculate pathways exhibited a loss of axonal coherence.…”

Magnetic resonance imaging assessment of the lateral geniculate nucleus volume and height in patients with glaucoma: a Meta-analysis

“…Therefore, we hypothesize that age-related LGN atrophy may exist in normal subjects, which makes the difference of LGN size between glaucoma and control groups in the older group smaller than that in the younger group. There was a significant difference in LGN volume measured by MRI between the early glaucoma group and the advanced glaucoma group [22,30] . The nasal optic nerve fibers of each eye converges with the temporal nerve fibers of the opposite eye and project to LGN.…”