Association Between the Deep-layer Microvasculature Dropout and the Visual Field Damage in Glaucoma

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma is a progressive optic neuropathy characterized by visual field (VF) loss.
• Microvasculature dropout (MvD_P) in the parapapillary region and focal lamina cribrosa (LC) defects are structural changes observed in glaucoma.
• The relationship between these structural changes and functional vision loss requires further elucidation.

Purpose of the Study:

• To compare visual field (VF) sensitivity based on the presence of parapapillary deep-layer microvasculature dropout (MvD_P) and focal lamina cribrosa (LC) defects.
• To investigate the association between these microvascular and structural changes and VF sensitivity in open-angle glaucoma.

Main Methods:

• 158 open-angle glaucoma patients were categorized into four groups based on the presence of MvD_P and focal LC defects using OCT angiography and spectral-domain OCT.
• Groups included: no defects, only LC defect, only MvD_P, and both defects.
• Visual field sensitivity and retinal nerve fiber layer (RNFL) thickness were compared across the four groups.

Main Results:

• Both RNFL thickness and VF sensitivity differed significantly among the groups, except in nasal and superonasal sectors for RNFL.
• Eyes with MvD_P (groups 3 and 4) exhibited significantly worse VF sensitivity compared to eyes with only LC defects (group 2).
• RNFL thickness did not significantly differ between groups with and without MvD_P, except in the superotemporal sector.

Conclusions:

• Eyes with MvD_P demonstrated worse VF sensitivity than those without MvD_P.
• The observed VF sensitivity differences were more pronounced than differences in axonal loss or focal LC changes.
• Further research is warranted to understand the temporal relationship between MvD_P and glaucomatous VF progression.