Relationship between Functional and Structural Changes in Diabetic Vessels in Optical Coherence Tomography Angiography.

Yuko Miwa,Shin Yoshitake,Akihito Uji,Kiyoshi Suzuma,Masahiro Fujimoto,Tomoaki Murakami,Tatsuya Yoshitake,Nagahisa Yoshimura,Yukino Tamura

doi:10.1038/srep29064

Yuko Miwa, Shin Yoshitake + Show 7 more

Open Access

https://doi.org/10.1038/srep29064

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Journal: Scientific reports	Publication Date: Jun 28, 2016
Citations: 89	License type: CC BY 4.0

Affiliation: Kyoto University

Abstract

The decorrelation signals in optical coherence tomography angiography (OCTA) are derived from the flow of erythrocytes and concomitantly delineate the retinal vasculature. We compared the structural and functional characteristics of vascular lesions visualized in fluorescein angiography (FA), OCTA, and en-face OCT images in 53 eyes (28 patients) with diabetic retinopathy (DR). The foveal avascular zone (FAZ) areas in OCTA images in the superficial layer almost corresponded to those in FA images. The FAZ areas in the en-face OCT images in the superficial layer were smaller than those in the FA images and correlated with each other, which agreed with the finding that en-face OCT images often delineated the vascular structure in the nonperfused areas in FA images. Microaneurysms appeared as fusiform, saccular, or coiled capillaries in OCTA images and ringed, round, or oval hyperreflective lesions in en-face OCT images. OCTA and en-face OCT images detected 41.0 ± 16.1% and 40.1 ± 18.6%, respectively, of microaneurysms in FA images, although both depicted only 13.9 ± 16.4%. The number of microaneurysms in FA images was correlated with that in OCTA and en-face OCT images. Comparisons of these modalities showed the associations and dissociations between blood flow and vascular structures, which improves the understanding of the pathogenesis of DR.

Highlights

Diabetic retinopathy (DR), a diabetic microangiopathy, often leads to severe visual loss in working-age patients[1,2]
The artifacts in the optical coherence tomography angiography (OCTA) images depend on the time-sequential differences of the optical coherence tomography (OCT) reflectivity beneath the vasculature, which suggested the clinical significance of the comparative studies between the OCTA and en-face OCT images for interpreting the three-dimensional vascular structures in individual eyes
Capillary nonperfusion has a significant impact on visual impairment and leads to vascular endothelial growth factor (VEGF) expression and concomitant pathogenesis in proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME), in vivo vascular pathophysiology in the nonperfused areas remains to be elucidated[3,4,10,11,24,25,26,27,28]

Summary

Introduction

Diabetic retinopathy (DR), a diabetic microangiopathy, often leads to severe visual loss in working-age patients[1,2]. Fluorescein angiography (FA), the gold standard for evaluating the retinal vasculature, shows both morphologic and functional changes in the blood vessels in DR. Fluorescein dye in the plasma delineates vascular lesions including loss of the capillary beds, and the dye leakage suggests dysfunction of the tightly regulated blood-retinal barrier[5,6,7]. OCT shows the qualitative and quantitative changes in the retinal parenchyma of the nonperfused areas, suggesting neuroglial structural changes and indirect proof of nutritional deficiency[10,11,12]. Decorrelation signals in OCTA images may depend on the movement of blood cells and resultantly delineate the morphologic and functional changes in the retinal vessels accompanied by blood flow. We quantified the foveal avascular zone (FAZ) areas and the number of microaneurysms in FA, OCTA, and en-face OCT images, and evaluated their relationship among the vascular changes in the images obtained using these modalities in DR

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Conclusion