Received: 9 May 2017 /Revised: 24 August 2017 /Accepted: 11 December 2017 / Published online: 13 January 2018
Springer-Verlag GmbH Germany, part of Springer Nature 2018
Purpose To evaluate the correlation between flow density, as measured by optical coherence tomography angiography (OCTA),
and structural and functional parameters in patients with open-angle glaucoma.
Methods Thirty-four eyes of 34 patients with open-angle glaucoma and 35 eyes of 35 healthy subjects were prospectively
included in this study. OCTA was performed using RTVue XR Avanti with AngioVue. The macula was imaged with a
3 × 3 mm scan and the optic nerve head (ONH) with a 4.5 × 4.5 mm scan. Visual field parameters [mean deviation (MD),
pattern standard deviation (PSD) and visual field index (VFI)], Bruch’s membrane opening minimal rim width (BMO-MRW),
retinal nerve fiber layer thickness (RNFLT) and the stereometric parameters rim area, cup/disc area (HRT III, Heidelberg Retina
Tomograph, Heidelberg Engineering) were tested for correlation with flow density data.
Results The flow density (whole en face) in the retinal OCT angiograms (superficial: p = 0.01; deep: p = 0.005), in the radial
peripapillary capillary network (p < 0.001) and in the OCT angiograms of the optic nerve head (p =0.004)weresignificantly
lower in the glaucoma group when compared with the control group. The flow density in the RPC network correlated signifi-
cantly with all functional and structural parameters tested. The strongest correlation was found between the RPC flow density
(inside disc) and the BMO-MRW (Spearman’s correlation coefficient = 0.912, p <0.001).
Conclusions Glaucoma patients showed a reduced ONH and macular perfusion when compared with healthy controls. The flow
density as measured by OCTA correlated with structural damage and visual field loss in glaucoma patients. Non-invasive
quantitative analyses of flow density using OCTA provide a new parameter describing a different aspect of glaucoma, which
could be useful in clinical practice.
Optical coherence tomography angiography
Optic nerve and macular perfusion
opening minimal rim width
Retinal nerve fiber layer thickness
Glaucoma is a leading cause of irreversible blindness world-
wide . The pathophysiology of glaucoma is complex and not
well understood. According to the mechanical theory, retinal
ganglion cell damage arises through increased intraocular pres-
sure (IOP), whereas the ‘vascular’ theory considers additional
factors such as blood flow in the pathogenesis of glaucoma [2,
3]. As a result, microvasculature perfusion and blood flow in
the optic nerve head (ONH) have been intensively investigated.
In clinical practice, a number of different diagnostic tools are
used to quantify and evaluate progression of glaucomatous
optic neuropathy. These include visual field testing, OCT im-
aging for scanning peripapillary retinal nerve fiber layer thick-
ness (RNFLT), and the evaluation of stereometric parameters
using Heidelberg retina tomography (HRT).
OCT angiography (OCTA) is a novel imaging technique,
enabling blood flow in normal and pathologic vascularization
* Maged Alnawaiseh
Department of Ophthalmology, University of Muenster Medical
Center, Albert-Schweitzer-Campus 1, Building D15,
48149 Muenster, Germany
Department of Ophthalmology, University of Würzburg,
Josef-Schneider-Str, 11 Würzburg, Germany
Graefe's Archive for Clinical and Experimental Ophthalmology (2018) 256:589–597
Correlation of flow density, as measured using optical coherence
tomography angiography, with structural and functional parameters
in glaucoma patients