Fig. 1. Patient data collection and screening process of the nationwide and multicenter study.

a The 200° UWF images were captured, and the renal function and medical history items were prospectively extracted from 23 tertiary hospitals nationwide in China (See Supplementary Note 1 for detailed hospital information). b 123,585 UWF images from 41,469 patients were initially collected. 218 images from 218 patients were finally included for training the UWF image segmentation model. 23,313 images from 7781 patients were finally included for creating the CKD screening model in a 7:1.5:1.5 distribution for internal training, validation, and test. 3226 images from 1352 patients from multicenter collection were used for outer validation. Blue arrows: patients and images permitted to subsequent procedures. Red arrows: excluded patients and images according to the exclusion criteria.