Tortuosity of Retinal Main and Branching Arterioles, Venules in Patients With Type 2 Diabetes and Diabetic Retinopathy in China

The epidemic studies have demonstrated an excessively increase of diabetic patients in recent years, who are at high risk of developing microvascular complications. Those microvascular complications usually lead to chronic health problems, e.g. diabetic retinopathy (DR), thus early and regular screening is indeed necessary. Retinal vascular tortuosity, which is one of geometrical parameters related to microvascular morphological changes, has been investigated in many studies related to diabetes, diabetic risk factors and diabetic complications. However, the global tortuosity of retinal vessels in DR progression is quantified either subjectively or imprecisely in those previous studies. Furthermore, to our best knowledge, the association of tortuosity, diabetes and DR has never been investigated based on a Chinese population-based cohort, even though it accounts for more than 30% of diabetic patients worldwide. Therefore, it is of great necessary and clinical significance to extract retinal tortuosity in a more reliable way and explore its associations with diabetic risk factors and DR severity in China. In this study, high contrast retinal images from 495 Chinese patients with type 2 diabetes were acquired by confocal scanning laser ophthalmoscope and the global tortuosity was extracted from main and branching arterioles, venules in the whole retinal image based on the theory of best-fit exponential curves in the roto-translation group SE(2). The statistical analysis results show that retinal arteriolar and venular tortuosity might be remarkable indices for assessing retinopathy severity and identifying individuals with high-risk of renal disease in diabetes, which may provide additional insights on microvascular changes for diabetic retina and kidney diseases.