Associations Between Diabetic Retinal Microvasculopathy and Neuronal Degeneration Assessed by Swept-Source OCT and OCT Angiography

Bingjie Qiu; Lin Zhao; Xinyuan Zhang; Yanhong Wang; Qiyun Wang; Yao Nie; Xiaosi Chen; Carol Y L Cheung

doi:10.3389/fmed.2021.778283

Associations Between Diabetic Retinal Microvasculopathy and Neuronal Degeneration Assessed by Swept-Source OCT and OCT Angiography

Front Med (Lausanne). 2021 Dec 10:8:778283. doi: 10.3389/fmed.2021.778283. eCollection 2021.

Authors

Bingjie Qiu^{1

2}, Lin Zhao¹, Xinyuan Zhang^{1

2}, Yanhong Wang³, Qiyun Wang^{1

2}, Yao Nie^{1

2}, Xiaosi Chen^{1

2}, Carol Y L Cheung⁴

Affiliations

¹ Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
² Beijing Retinal Choroidal Vascular Diseases Study Group.
³ Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences & School of Basic Medicine Peking Union Medical College, Beijing, China.
⁴ Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.

Abstract

Purpose: To provide clinical evidence of the associations between retinal neuronal degeneration and microvasculopathy in diabetic retinopathy (DR). Methods: This case-control study included 76 patients (76 eyes) with type 2 diabetes mellitus (DM), and refraction error between -3.0 and +3.0 D. The eyes were assigned into DM (without DR), non-proliferative DR (NPDR), and proliferative DR (PDR) groups. Age-, sex-, and refractive error-matched normal subjects were enrolled as controls. The mean retinal thickness (mRT), the relative mean thickness of the retinal nerve fiber layer (rmtRNFL, mtRNFL/mRT), ganglion cell layer (rmtGCL), ganglion cell complex (rmtGCC) layer, foveal avascular zone area (FAZa), FAZ perimeter (FAZp), FAZ circularity index (FAZ-CI), and vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP) were assessed by swept-source optical coherence tomography (OCT) and OCT angiography (OCTA). Group comparison and Spearman's partial correlation coefficient analysis were applied to evaluate the correlation between these morphological parameters. Results: rmtRNFL, FAZa, and FAZp in SCP and DCP increased with the DR severity (p _rmtRNFL < 0.001; p _{FAZa, SCP} = 0.001; p _FAZa , _DCP = 0.005; p _FAZp , _SCP < 0.001; p _FAZp , _DCP < 0.001). The rmtGCL, FAZ-CI in SCP and DCP, and VD in DCP decreased with the DR severity (p _rmtGCL = 0.002, p _FAZ-CI , _SCP = 0.002; p _{FAZ-CI, DCP} < 0.001, p _VD , _DCP < 0.001). After controlling age, sex, duration of diabetes, and hypertension, the rmtRNFL, FAZa in SCP and DCP, and FAZp in SCP and DCP were correlated with the severity of DR (p < 0.05), while VD in SCP and DCP, FAZ-CI, and rmtGCL were negatively correlated with the severity of DR (p < 0.05). The rmtGCL was negatively correlated with the FAZa in SCP (r = -0.34, p = 0.002) and DCP (r = -0.23, p = 0.033), and FAZp in SCP (r = -0.37, p = 0.001) and DCP (r = -0.32, p = 0.003), but positively correlated with VD in SCP (r = 0.26, p = 0.016), VD in DCP (r = 0.28, p = 0.012), and FAZ-CI in DCP (r = 0.31, p = 0.006). Conclusions: rmtRNFL, FAZ-CI in SCP and DCP, and FAZp in SCP are strong predictors of the severity of DR. The ganglion cell body loss is highly correlated with increased FAZp and FAZa, decreased FAZ-CI, and reduced VD with the severity of DR.

Keywords: OCT angiography; diabetic microvasculopathy; diabetic retinopathy; retinal neuronal degeneration; swept source optical coherence tomography.