Peripapillary and Macular Vessel Density in Patients with Glaucoma and Single-Hemifield Visual Field Defect

Abstract

Purpose: To compare hemifield differences in the vessel density of the peripapillary and macula in open-angle glaucoma eyes with visual field (VF) defect confined to one hemifield using optical coherence tomography angiography (OCT-A).

Design: Cross-sectional study.

Participants: A total of 58 eyes of 58 patients with glaucoma with VF loss confined to a single hemifield and 28 healthy eyes.

Methods: Retinal vasculature information was summarized as circumpapillary vessel density (cpVD) and perifoveal vessel density (pfVD). Circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (mGCC) thickness were calculated using spectral domain optical coherence tomography (SD OCT). Paired and unpaired t tests were used to evaluate differences between the perimetrically affected and intact hemiretinae and healthy hemiretinae. Linear regression analyses were performed to evaluate the associations between VF measures with vascular and structural measurements.

Main outcome measures: Total and hemispheric cpVD, pfVD, cpRNFL, mGCC, and mean sensitivity (MS).

Results: Mean cpVD and pfVD in the intact hemiretinae of glaucoma eyes (59.0% and 51.1%, respectively) were higher than in the affected hemiretinae (54.7% and 48.3%, respectively; P < 0.001) but lower than in healthy eyes (62.4% and 53.8%, respectively; P < 0.001). Similar results were noted with cpRNFL and mGCC thickness measurements (P < 0.05 for both). The strongest associations between MS in the affected hemifields were found for cpVD (r = 0.707), followed by pfVD (r = 0.615), cpRNFL (r = 0.496), and mGCC (r = 0.482) in the corresponding hemiretinae (P < 0.001 for all). Moreover, the correlations in the intact hemifields between MS with cpVD and pfVD were higher (r = 0.450 and 0.403) than the correlations between MS and cpRNFL and mGCC thickness measurements (r = 0.340 and 0.290; P values <0.05 for all).

Conclusions: Reduced peripapillary and macular vessel density was detectable in the perimetrically intact hemiretinae of glaucoma eyes with a single-hemifield defect. Vessel density attenuation in both affected and intact hemiretinae was associated with the extent of VF damage in the corresponding hemifields. Optical coherence tomography angiography potentially shows promise for identifying glaucomatous damage before focal VF defects are detectable.

Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Top row: Vessel density map of the peripapillary retinal nerve fiber layer with circumpapillary (cpVD) measurement region defined (left) and macular superficial layer with perifoveal (pfVD) measurement region defined (right). Bottom row: spectral domain optical coherence tomography (SD-OCT) optic nerve head (ONH) thickness map (left) and macular ganglion cell complex (mGCC) thickness map (right).

Figure 2

A representative glaucoma eye with superior visual field defect: Top row: standard automated perimetry (SAP) results showing superior visual field. Middle row: macular ganglion cell complex (mGCC) thickness map (left) and optic nerve head (ONH) thickness map (right) representing mGCC and circumpapillary retinal nerve fiber layer (cpRNFL) loss corresponding to the visual field defect. Bottom line: Vessel density map of the peripapillary retinal nerve fiber layer (right) and macular superficial layer (left) illustrating reduced vasculature that spatially correlates with the location of structural loss and visual field defect.

Figure 3

Top row: Vessel density map of the macular superficial layer (left) and peripapillary retinal nerve fiber layer (right) showing denser microvascular networks in healthy eyes in both regions. Bottom row: Area vessel density color-coded map of the macular superficial layer (left) and peripapillary retinal nerve fiber layer (right), in which the orange color indicates a vessel density of greater than 50% perfused vessels, dark blue indicates no perfused vessels detected, and intermediate vessel density values vary from yellow to green.

Figure 4

Scatterplots illustrating the linear (grey line) associations between standard automated perimetry (SAP) mean sensitivity in the affected hemifields and optical coherence tomography angiography (OCT-A) circumpapillary vessel density (cpVD), perifoveal vessel density (pfVD), spectral domain optical coherence tomography (SD-OCT) retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness measurements in the corresponding hemiretinae of glaucoma eyes. r: correlation coefficient from the fitted linear regression model.

Figure 5

Scatterplots illustrating the linear (grey line) associations between standard automated perimetry (SAP) mean sensitivity in the perimetrically intact hemifields and optical coherence tomography angiography (OCT-A) circumpapillary vessel density (cpVD), perifoveal vessel density (pfVD), spectral domain (SD) OCT retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness measurements in the corresponding hemiretinae of glaucoma eyes. r: correlation coefficient from the fitted linear regression model.