Serum Fibroblast Growth Factor 21 Levels Are Correlated with the Severity of Diabetic Retinopathy oleh Yuan Lin, Ye-cheng Xiao, Hong Zhu, Qing-yan Xu, Lei Qi, Yu-bin Wang, Xiu-juan Li, Ma-li Zheng, Rui-sheng Zhong, Yi Zhang, Xiang-dong Xu, Bo-le Wu, Zhu-mei Xu, Xiang-hong Lu