Abstract: Objective To analyze the relationship between severity of diabetic retinopathy (DR) and blood glucose fluctuations in patients with type 2 diabetes mellitus (T2DM) and its influencing factors. Design Retrospective case series. Participants Using convenience sampling method to select 168 T2DM patients admitted to Changshu Hospital from February 2021 to April 2023. Methods According to the severity of DR, the patients were divided into 88 cases in non-DR group (NDR), 59 cases in non-proliferative DR group (NPDR) and 21 cases in proliferative DR group (PDR). The basic data, laboratory indicators and 14-day continuous glucose monitoring (CGM) results were compared among the three groups. The influencing factors of progression of DR were explored by multivariate Logistic regression analysis, and receiver operating characteristic curve (ROC) was drawn. The predictive efficiency of time in range (TIR) and mean amplitude of glycemic excursions (MAGE) on predicting the progression of DR was assessed. Main Outcome Measures TIR, mean blood glucose (MBG), standard deviation of blood glucose level (SDBG), MAGE. Results Age, diabetes course, fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) levels were manifested as NDR group<NPDR group<PDR group (all P<0.05). The TIR value was expressed as NDR group (79.78%±14.03%)>NPDR group (67.51%±12.75%)>PDR group (50.17%±10.18%) (all P<0.05), while the MBG level revealed NDR group [(8.15±1.76) mmol/L]<NPDR group [(8.77±1.89) mmol/L]<PDR group [(9.79±2.16) mmol/L] (all P<0.05). The SDBG level showed NDR group [(1.84±0.48) mmol/L]<NPDR group [(2.39±0.62) mmol/L]<PDR group [(2.68±0.75) mmol/L] (all P<0.05). The MAGE level was considered as NDR group [(4.33±1.04) mmol/L]<NPDR group [(5.48±1.34) mmol/L]<PDR group [(6.67±1.69) mmol/L] (all P<0.05). ROC curve analysis found that TIR<60.22%, MAGE>6.17 mmol/L and HbA1c>8.83% could all predict PDR (all P<0.05), and the areas under the curves were 0.918, 0.684 and 0.680, and TIR had the highest prediction efficiency (Z=3.105, 3.401; P=0.002, 0.001), and its sensitivity and specificity were 90.48% and 82.31%. Multivariate Logistic regression analysis showed that MAGE>6.17 mmol/L and TIR<60.22% were independent risk factors for PDR (all P<0.05). Conclusion The severity of DR in T2DM patients is closely related to the fluctuations of blood glucose. MAGE>6.17 mmol/L and TIR<60.22% will increase the risk of NDR and NPDR developing into PDR, and TIR and MAGE can be used as predictive indicators of NDR and NPDR. (Ophthalmol CHN, 2025, 34: 137-141)

Key words:  type 2 diabetes mellitus, diabetic retinopathy