To assess the relationship between optic disc vessel density (ODVD) reduction and visual field (VF) progression according to disease severity in primary open-angle glaucoma (POAG).

Retrospective case series.

A total of 345 POAG patients categorized into early ( n = 153), moderate ( n = 98), and advanced ( n = 94) groups according to the baseline VF mean deviation (≥-6 dB, -12 dB – -6 dB, and < -12 dB) underwent ≥ 5 optical coherence tomography (OCT), OCT angiography (OCTA), and ≥ 3 years of VFs. ODVD was calculated as the ratio of pixels occupied by vessels within the temporal optic disc on OCTA. The association between VF progression and the ODVD change rate per year was assessed using logistic and Cox Proportional Hazards (PH) models across the three groups.

ODVD reduction rate was significantly faster in VF progressors than in non-progressors in all three groups ( P < .001). VF progression was associated with the rate of global ODVD change (odds ratio [OR] = 1.27 for the early, OR = 1.39 for the moderate, and OR = 1.48 for the advanced; all P < .05) and with the binary ODVD reduction (OR = 6.13 for early, OR = 5.23 for moderate, and OR = 14.0 for advanced; all P < .05) in the multivariable logistic regression across all three groups. In the multivariable Cox PH model, a significant association of the rate of global ODVD change and the binary ODVD reduction with VF progression was observed in both early (hazards ratios [HRs] (95% CI) = 1.29 and 4.32; both P < .001) and moderate-to-advanced glaucoma (HRs (95% CI) = 1.23 and 2.83; both P < .001).

Reduction of optic disc microvasculature is useful for detecting glaucoma progression, in patients with advanced glaucoma, as well as those with early and moderate glaucoma.