Vasculature–function relationship in open-angle glaucomatous eyes with a choroidal microvasculature dropout

Abstract

Identifying biomarkers associated with functional impairment is important in monitoring glaucoma patients. This retrospective cross-sectional study investigated the vasculature–function relationship in open-angle glaucoma (OAG) eyes with choroidal microvasculature dropout (CMvD) versus in OAG eyes without. Optical coherence tomography (OCT) angiography-derived circumpapillary (cpVD) and macular vessel densities (mVD) were measured in 159 early-stage OAG eyes (mean deviation > −6 dB) in accordance with the presence or not of a CMvD. OCT-derived circumpapillary retinal nerve fibre layer thickness (cpRNFLT) and macular ganglion cell-inner plexiform layer thicknesses (mGCIPLT) were also measured as reference standards. The vasculature (cpVD and mVD)–function [24-2 visual field mean sensitivity (VFMS) and central 10° VFMS (cVFMS)] and structure (cpRNFLT and mGCIPLT)–function (24-2 VFMS and cVFMS) relationships were compared using global and sectoral maps between OAG eyes with (CMvD+) and without CMvD (CMvD−). The CMvD+ eyes showed significantly steeper cpVD-24-2 VFMS and mVD-cVFMS correlations (P < 0.05). In contrast, there were no significant differences in the cpRNFLT-24-2 VFMS and mGCIPLT-cVFMS relationships between the two groups (P > 0.05). In conclusion, OAG eyes with a CMvD have significantly stronger vasculature–function relationships than eyes without. Vessel density parameters may be useful biomarkers of disease progression in early-stage OAG patients with a CMvD.

Comparison of the Circumpapillary Structure-Function and Vasculature-Function Relationships at Different Glaucoma Stages Using Longitudinal Data

“…1 A2 and 1 B2). 15 , 22 Any initial or follow-up SD-OCT and OCTA images were excluded from the analysis if they met any of the following criteria: (1) poor image quality with a signal strength < 7; (2) motion artifacts; (3) localized weak signal intensity due to vitreous floaters or media opacity; (4) poor centration; or (5) segmentation failure.…”

“…The regional VFMS values were also determined by averaging the threshold values in each of the hemifield and six sectors (i.e., SN, N, IN, IT, T, and ST) as described elsewhere. 15 , 23 , 24 …”

“… 13 , 14 Notably, a significant vasculature-function (V-F) relationship, determined using VD parameters derived from OCTA measurements, has been well established in advanced glaucoma across several studies. 7 , 8 , 15 Nonetheless, all of these prior studies were based on a cross-sectional design, indicating the need for longitudinal reports. As the measurement floor of VD parameters was reported to be lower than that of structural parameters across the glaucoma continuum, 13 , 14 we hypothesized that the longitudinal S-F and V-F relationships may differ according to glaucoma stage.…”