A software for quantification of vessel density in glaucoma: An OCT-Angiography study

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Assessing microvascular changes in the optic nerve head is crucial for glaucoma diagnosis.
• Current methods for quantifying peripapillary vascularity have limitations.

Purpose of the Study:

• To evaluate capillary vessel density in the peripapillary region of glaucoma patients versus healthy controls.
• To develop and utilize automated software for quantifying peripapillary capillary density.
• To assess the diagnostic utility of optical coherence tomography angiography (OCT-A) in glaucoma.

Main Methods:

• An observational, cross-sectional case-control study included 72 glaucoma eyes and 30 healthy control eyes.
• Optical coherence tomography angiography (OCT-A) scans (4.5x4.5mm) centered on the optic nerve head were acquired.
• Custom software was developed to remove large vessels and quantify capillary density in the peripapillary region.

Main Results:

• Capillary vessel density (VD) was significantly lower in glaucoma patients (72.45±7.45%) compared to controls (77.87±3.77%).
• VD correlated with visual field mean deviation (Spearman correlation = 0.33, P=0.0017).
• Receiver operating characteristic (ROC) analysis showed moderate diagnostic ability for OCT-A VD (0.629±0.143), outperforming visual field and OCT-derived retinal nerve fiber layer thickness.

Conclusions:

• The developed software effectively quantifies vessel density at optic disc and peripapillary capillary levels.
• This quantification aids in documenting glaucomatous vascular changes.
• OCT-A shows potential utility as a diagnostic tool for glaucoma.