Retinal vascular morphological characteristics in diabetic retinopathy: an artificial intelligence study using a transfer learning system to analyze ultra-wide field images
Authors:   Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People&#x2019;s Hospital (Affiliated People&#x2019;s Hospital, Hangzhou Medical College), Hangzhou 310014, Zhejiang Province, China, Deng Xin-Yi , Zhang Zheng-Xi ,   Department of Retina, Eye Hospital of Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China, Li Han-Xiao ,   Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People&#x2019;s Hospital (Affiliated People&#x2019;s Hospital, Hangzhou Medical College), Hangzhou 310014, Zhejiang Province, China, Wang Jun ,   Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People&#x2019;s Hospital (Affiliated People&#x2019;s Hospital, Hangzhou Medical College), Hangzhou 310014, Zhejiang Province, China, Chen Yi-Qi ,   Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People&#x2019;s Hospital (Affiliated People&#x2019;s Hospital, Hangzhou Medical College), Hangzhou 310014, Zhejiang Province, China, Mao Jian-Bo ,   Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People&#x2019;s Hospital (Affiliated People&#x2019;s Hospital, Hangzhou Medical College), Hangzhou 310014, Zhejiang Province, China, Sun Ming-Zhai ,   Department of Precision Machinery and Instrumentation, University of Science and Technology of China, Hefei 230026, Anhui Province, China, Shen Li-Jun ,   Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People&#x2019;s Hospital (Affiliated People&#x2019;s Hospital, Hangzhou Medical College), Hangzhou 310014, Zhejiang Province, China
Published: May 2024

AIM: To investigate the morphological characteristics of retinal vessels in patients with different severity of diabetic retinopathy (DR) and in patients with or without diabetic macular edema (DME).
METHODS: The 239 eyes of DR patients and 100 eyes of healthy individuals were recruited for the study. The severity of DR patients was graded as mild, moderate and severe non-proliferative diabetic retinopathy (NPDR) according to the international clinical diabetic retinopathy (ICDR) disease severity scale classification, and retinal vascular morphology was quantitatively analyzed in ultra-wide field images using RU-net and transfer learning methods. The presence of DME was determined by optical coherence tomography (OCT), and differences in vascular morphological characteristics were compared between patients with and without DME.
RESULTS: Retinal vessel segmentation using RU-net and transfer learning system had an accuracy of 99% and a Dice metric of 0.76. Compared with the healthy group, the DR group had smaller vessel angles (33.68±3.01 vs 37.78±1.60), smaller fractal dimension (Df) values (1.33±0.05 vs 1.41±0.03), less vessel density (1.12±0.44 vs 2.09±0.36) and fewer vascular branches (206.1±88.8 vs 396.5±91.3), all P<0.001. As the severity of DR increased, Df values decreased, P=0.031. No significant difference between the DME and non-DME groups were observed in vascular morphological characteristics.
CONCLUSION: In this study, an artificial intelligence retinal vessel segmentation system is used with 99% accuracy, thus providing with relatively satisfactory performance in the evaluation of quantitative vascular morphology. DR patients have a tendency of vascular occlusion and dropout. The presence of DME does not compromise the integral retinal vascular pattern.