Multimodality analysis of Hyper-reflective Foci and Hard Exudates in Patients with Diabetic Retinopathy

Sijie Niu,Qiang Chen,Songtao Yuan,Qinghuai Liu,Chenchen Yu,Wen Fan,Jiang Lin

doi:10.1038/s41598-017-01733-0

Abstract

To investigate the correlations between hyper-reflective foci and hard exudates in patients with non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) by spectral-domain optical coherence tomography (SD OCT) images. Hyper-reflective foci in retinal SD OCT images were automatically detected by the developed algorithm. Then, the cropped CFP images generated by the semi-automatic registration method were automatically segmented for the hard exudates and corrected by the experienced clinical ophthalmologist. Finally, a set of 5 quantitative imaging features were automatically extracted from SD OCT images, which were used for investigating the correlations of hyper-reflective foci and hard exudates and predicting the severity of diabetic retinopathy. Experimental results demonstrated the positive correlations in area and amount between hard exudates and hyper-reflective foci at different stages of diabetic retinopathy, with statistical significance (all p < 0.05). In addition, the area and amount can be taken as potential discriminant indicators of the severity of diabetic retinopathy.

Highlights

Diabetic retinopathy (DR), a common microvascular complication of diabetes, remains the leading cause of vision loss in many developed countries and continues to increase in developing countries[1,2,3]
The aim of this study is to investigate the associations between hyper-reflective foci and hard exudates in patients with diabetic retinopathy based on extracting a set of quantitative features that characterize the phenotypes associated with them in spectraldomain optical coherence tomography (SD optical coherence tomography (OCT)) images
Previous work[18,19,20,21,22,23,24,25,26,27,28] studied changes in hard exudates or hyper-reflective foci in patients with diabetic macular edema (DME) using SD OCT images, they did not assess the relationship between hard exudates and hyper-reflective foci in SD OCT images or evaluate DR severity using a set of quantitative imaging features

Summary

Introduction

Diabetic retinopathy (DR), a common microvascular complication of diabetes, remains the leading cause of vision loss in many developed countries and continues to increase in developing countries[1,2,3]. Diabetic retinopathy is normally categorized into two main types: non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) In both NPDR and PDR, the breakdown of the blood-retinal barrier often causes retinal changes such as hemorrhages, hard exudates (HEs), and hyper-reflective foci (HRF), which may lead to decreased vision[5]. Several studies have performed analysis to determine the hyper-reflective foci or hard exudate associated with diabetic macular edema (DME) using OCT images. We systematically analyzed the existing studies of HRF and HEs in patients with DME and concluded that increasing numbers of hyper-reflective regions seem to be associated with an increased risk of visual loss. Due to their density and opacity, hard exudates are observed as hyper-reflective lesions in SD OCT B-scans; it is a challenging task to study the regions where hyper-reflective foci are taken as hard exudates on SD OCT images and to explore the potential discriminant indicators of the severity of diabetic retinopathy

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Conclusion