Quantitative automated circumpapillary microvascular density measurements: a new angioOCT-based methodology

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Glaucoma diagnosis relies on detecting optic nerve damage.
• Microvascular changes in the optic nerve head are increasingly recognized as early indicators of glaucoma.
• Optical coherence tomography angiography (angioOCT) offers high-resolution imaging of microvasculature.

Purpose of the Study:

• To develop and validate a novel angioOCT-based methodology for quantifying circumpapillary microvascular density (cpmVD).
• To assess the utility of cpmVD as a biomarker for detecting glaucoma damage.

Main Methods:

• AngioOCT scans from healthy subjects and glaucoma patients were analyzed.
• A specific region of interest around the optic disc was defined for cpmVD calculation.
• The developed method excluded major retinal vessels to focus on microvascular density.
• Circumpapillary microvascular density (cpmVD) and sectorial microvascular density (mVD) were compared with retinal nerve fibre layer (RNFL) thickness.

Main Results:

• Glaucoma patients exhibited significantly lower cpmVD across all visual field sectors compared to healthy individuals.
• The inferior and superior sectors showed the most pronounced differences in mVD between groups.
• Glaucoma was associated with reduced variability in cpmVD compared to healthy controls.
• The methodology demonstrated robustness against factors like movement artifacts and optic disc variations.

Conclusions:

• The developed open-source methodology provides a reliable quantitative analysis of 360° microvascular density.
• Circumpapillary microvascular density (cpmVD) and sectorial mVD measured by angioOCT are suitable for routine glaucoma assessment.
• This technique offers a promising new approach for early glaucoma detection and monitoring.