Optic Disc Perfusion in Primary Open Angle and Normal Tension Glaucoma Eyes Using Optical Coherence Tomography-Based...

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Optic disc microvascular changes are implicated in glaucoma pathogenesis.
• Quantifying optic disc perfusion is crucial for understanding glaucoma progression.

Purpose of the Study:

• To compare optic disc perfusion between normal, primary open-angle glaucoma (POAG), and normal tension glaucoma (NTG) eyes.
• To utilize optical microangiography (OMAG) based optical coherence tomography (OCT) angiography for detailed microvascular assessment.
• To investigate the relationship between optic disc perfusion and glaucoma severity.

Main Methods:

• A cross-sectional study involving 28 normal, 30 POAG, and 31 NTG subjects.
• OMAG-OCT angiography was used to scan the optic nerve head (ONH) in one eye per subject.
• The pre-laminar layer (preLC) microvasculature was segmented, and perfusion metrics (flux, vessel area density, normalized flux) were quantified.

Main Results:

• Glaucomatous eyes (POAG and NTG) showed significantly reduced optic disc perfusion compared to normal eyes (p<0.0001).
• No significant perfusion differences were found between POAG and NTG groups with similar visual field damage.
• Optic disc perfusion correlated significantly with visual field mean deviation (MD), pattern standard deviation (PSD), and rim area in glaucomatous eyes.

Conclusions:

• OMAG effectively detects reduced optic disc perfusion in glaucoma patients.
• Perfusion metrics correlate with functional (visual field) and structural (rim area) parameters in glaucoma.
• OMAG-based vascular assessment holds potential for glaucoma diagnosis and monitoring.