Quantitative analysis of OCT-A images requires a reproducible approach that accounts for sectoral loss. This study’s objective was to determine whether an index that accounts for both global (perfusion density, PD) and asymmetric loss of perfusion, rather than PD alone, more reliably measures perfusion loss in patients with glaucoma.

We analyzed macular OCT-A scans of 95 glaucoma patients and 59 control subjects. 2-D projection images corresponding to the superficial vascular plexus were exported, and analyses were performed.

Median (IQR) visual field mean deviation was −1.73 dB for the glaucoma group and 0.67 (0.16, 1.18) dB for the control group. The correlation with mean deviation was stronger for PAI, compared with PD, whereas with GCL thickness, they were comparable. Compared with controls, the mean PD was 12% lower in patients with glaucoma, while PAI was 17% lower. However, the diagnostic accuracy of either PD or PAI was worse than GCL thickness.

While PAI yielded better correlation with mean deviation and GCL thickness and a slightly improved separation between patients with glaucoma and healthy controls, diagnostic accuracy was inferior compared with GCL thickness.

Reference: https://bjo.bmj.com/content/104/12/1724