Changes of Visual Pathway and Brain Connectivity in Glaucoma: A Systematic Review

Area of Science:

• Neuroscience
• Ophthalmology
• Medical Imaging

Background:

• Glaucoma is a primary cause of irreversible blindness globally.
• Understanding cortical visual pathway involvement is crucial for neuroprotection and neuroregeneration therapies in glaucoma.

Purpose of the Study:

• To review current knowledge on brain structural, functional, and metabolic changes in glaucoma patients using advanced neuroimaging techniques.

Main Methods:

• Systematic literature search of multiple databases until October 2017.
• Inclusion of studies with at least six glaucoma patients.
• Analysis of neuroimaging techniques including fMRI, rs-fMRI, MRS, VBM, SBM, and DTI.

Main Results:

• 56 studies involving 2,381 patients revealed neurodegeneration within and beyond the visual system.
• Structural changes (reduced thickness/volume) observed in visual cortex and association areas.
• Functional and metabolic abnormalities found in primary visual cortex; disrupted connectivity noted in resting-state fMRI.

Conclusions:

• Neuroimaging confirms widespread brain changes in glaucoma patients.
• Findings support the potential for brain plasticity and new therapeutic strategies for cortical degeneration.
• Structural, functional, and metabolic alterations extend beyond the visual pathway.