Quantitative optical coherence tomography angiography of macular vascular structure and foveal avascular zone in glaucoma.

Jaewan Choi,Joong Won Shin,Junki Kwon,Michael S Kook,Saem Lee,Jiyun Lee,Sanjoy Bhattacharya

doi:10.1371/journal.pone.0184948

Jaewan Choi, Joong Won Shin + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0184948

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Journal: PloS one	Publication Date: Sep 21, 2017
Citations: 102	License type: CC BY 4.0

Affiliation: University of Ulsan, Asan Medical Center, Ulsan College

Abstract

ObjectiveThe study aimed to evaluate the quantitative characteristics of the macular vessel density (VD) and foveal avascular zone (FAZ) in glaucoma using optical coherence tomography angiography (OCT-A).DesignCross-sectional, age- and sex-matched case–control study.MethodsFifty-two eyes of 52 patients with primary open angle glaucoma and 52 eyes from 52 healthy participants were recruited retrospectively. OCT-A was performed on a 3 x 3-mm macular region centered on the fovea. OCT-A scans were manually graded to define the FAZ. Parafoveal VD in superficial and deep retina were analyzed in the circular- and quadrant-segmented zone. The FAZ parameters included size, perimeter, and circularity index. The regression analysis among VD and FAZ-related parameters and ocular parameters was performed, and the diagnostic ability was calculated with refractive error adjusted.ResultsFor both groups, the mean age and the sex ratio was not different between groups. With refractive error adjusted, the average macular VD was lower in glaucoma than in the control group for superficial (P = 0.013), deep (P<0.001), and the whole retina (P = 0.002). There were increased FAZ perimeter and decreased FAZ circularity index in glaucoma when compared with controls (P<0.001). In the multivariate regression models, FAZ circularity index were significantly associated with decreased peripapillary RNFL thickness (P = 0.007) and macular GCIPL thickness (P = 0.009) measured by OCT. The refractive-error adjusted area under receiver operating characteristics was highest for FAZ circularity index (0.905; 95% CI, 0.844–0.966), followed by temporal deep retinal VD (0.870; 95% CI, 0.803–0.937) and FAZ perimeter (0.858; 95% CI, 0.784–0.932).ConclusionsDecreased macular VD, increased FAZ perimeter, and decreased FAZ circularity index were observed in eyes with glaucoma using OCT-A. With refractive error adjusted, these parameters showed considerable diagnostic value for glaucoma. FAZ circularity index may be a novel biomarker representing disruption of the parafoveal capillary network in glaucoma, as supported by its association with structural parameters.

Highlights

Hypotheses associated with the development of primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) can be largely classified into those involving vascular factors, [1,2,3,4,5] and those involving biomechanical stress such as intraocular pressure (IOP) or thin lamina cribrosa.[6,7,8,9] IOP has been regarded as the most important risk factor in the management of glaucoma, reducing IOP does not always guarantee the cessation of the disease progression
The average macular vessel density (VD) was lower in glaucoma than in the control group for superficial (P = 0.013), deep (P
There were increased foveal avascular zone (FAZ) perimeter and decreased FAZ circularity index in glaucoma when compared with controls (P

Summary

Introduction

Hypotheses associated with the development of primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) can be largely classified into those involving vascular factors, [1,2,3,4,5] and those involving biomechanical stress such as intraocular pressure (IOP) or thin lamina cribrosa.[6,7,8,9] IOP has been regarded as the most important risk factor in the management of glaucoma, reducing IOP does not always guarantee the cessation of the disease progression. Recent studies have proposed that POAG and NTG may represent a continuum of open-angle glaucoma (OAG) that differs primarily in predominant causative risk factors, with higher IOP being important in POAG, whereas additional IOP-independent factors such as nocturnal hypotension or circadian fluctuation of mean ocular perfusion pressure may be more important in NTG.[1, 2, 10,11,12]. It may be contributed to by individual differences in flow parameter readings in some OBF-measuring devices in clinical practice.[19]

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