Early changes of brain connectivity in primary open angle glaucoma.

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Recent studies suggest diffuse brain changes in advanced POAG.
• Early detection of these changes is crucial for understanding disease progression.

Purpose of the Study:

• To investigate if diffuse brain changes, seen in advanced POAG, are also present in early stages.
• To assess anatomical connectivity (AC) and functional connectivity (FC) in different POAG stages using multimodal MRI.
• To correlate brain changes with visual field and retinal nerve fiber layer thickness.

Main Methods:

• Multimodal magnetic resonance imaging (MRI) was used in 57 POAG patients across three stages and 29 age-matched normal controls (NC).
• Voxelwise statistics with nonparametric permutation testing were employed.
• Analysis focused on disruptions in AC and FC within visual and nonvisual pathways.

Main Results:

• POAG patients exhibited disrupted AC along visual and nonvisual pathways compared to NC.
• Decreased FC was observed in visual and working memory networks; increased FC in default mode and subcortical networks.
• Altered AC and FC were evident in early POAG, with gray matter atrophy appearing in severe stages.
• Brain changes correlated significantly with visual field and retinal nerve fiber layer thickness.

Conclusions:

• The pathogenesis of POAG involves widespread AC damage and altered FC, extending beyond the visual system from the early disease stage.
• Brain MRI findings, including connectivity alterations and atrophy, are associated with POAG severity.
• These findings highlight the clinical relevance of brain changes in POAG and their early onset.