Author:

Abstract:

Purpose: To develop a new methodology to identify glaucoma patients based on micro-vascular density (mVD) as measured by Optical Coherence Tomography Angiography (angio-OCT). Methods: A random eye of 36 healthy subjects (aged 63 ± 12 years) and 33 glaucoma patients (aged 61 ± 8 years with an average visual field loss of -9.5 ± 6.8 dB) were used to build a new angio-OCT evaluation technique (Zeiss Cirrus 5000 HD-OCT). Optic disc centred 3x3mm images were collected. An annular area with an inner radius of 1.16mm and outer radius of 1.44mm was selected as the region of interest (ROI). The lower envelope of each circular line in the ROI was obtained after applying a third-order median filter. Hence, the mVD was calculated averaging each radial line of the ROI. In addition, the average intensity at various spatial locations according to the Garway-Heath sectors was calculated. Results: A significant decrease of the mVD was observed in the glaucoma group for all Garway-Heath sectors (p<0.001). Moreover, mVD in the supero-temporal and infero-temporal sectors was the most discriminative when comparing to the normal group. Lastly, it was also observed that glaucoma contributes to an mVD attenuation of variability between sectors when compared to the healthy group. Conclusions: The presented technique shows the potential of the mVD measured by angio-OCT to be used in everyday glaucoma practice.