Statistical analyses were performed using SPSS software version 18.0 for Windows (SPSS, Inc., Chicago, IL, USA). The variables are expressed as the mean ± standard deviation or n (%). The groups were compared by 1-way analysis of variance with the post hoc Bonferroni method, analysis of covariance (ANCOVA), and χ2 tests. To assess the relationship between plasma Sema3A levels and nonperfusion area, total macular volume, and the urine albumin-to-creatinine ratio, Pearson's correlation coefficients were calculated. P values less than 0.05 were considered to indicate statistical significance. Multiple linear regression analysis was used to adjust for age, sex, severity of diabetic retinopathy, hemoglobin A1c (HbA1c), diabetes duration, presence of HTN, eGFR, and the urine albumin-to-creatinine ratio.