Recent pathogenic concepts of primary open angle glaucoma and soft glaucoma (POAG)

Area of Science:

• Ophthalmology
• Neuroscience
• Pathology

Background:

• Primary open-angle glaucoma (POAG) is characterized by progressive visual field loss.
• Schnabel's cavernous atrophy, involving glial collagen tissue, is implicated in axonal damage at the optic nerve's scleral passage.
• Elevated intraocular pressure (IOP) is a known risk factor, but its precise role in POAG pathogenesis is debated.

Purpose of the Study:

• To investigate the potential shared pathogenic mechanism underlying both optic nerve damage (cavernous atrophy) and elevated IOP in POAG.
• To explore whether collagen abnormalities in the optic nerve and trabecular meshwork are linked.
• To evaluate the implications for understanding POAG as a disease of the optic nerve.

Main Methods:

• Histopathological examination of optic nerve tissue to analyze collagen structure and glial organization.
• Correlation of structural findings with visual field data and IOP measurements.
• Pathophysiological modeling to assess the impact of collagen changes and hemodynamic factors.

Main Results:

• POAG-related field loss is associated with Schnabel's cavernous atrophy, characterized by collagen (types IV and I) and capillary-containing tissue plates.
• Axonal organization within the optic nerve lesion is irregular, suggesting a primary optic nerve disease.
• A unifying pathogenic mechanism affecting collagen in both the lamina cribrosa and trabecular meshwork is hypothesized.

Conclusions:

• POAG may be fundamentally a disease of the optic nerve, with elevated IOP being a contributing or exacerbating factor rather than the sole cause.
• Shared collagen pathology could explain both optic nerve damage and trabecular meshwork changes.
• Accurate prediction of visual field loss is crucial for treatment decisions and requires further research.