摘要目的 分析降糖治疗对糖尿病患者眼屈光度的影响,探讨其发生机制.方法 选择20例新诊断的糖尿病患者,检测治疗前随机血糖、糖化血红蛋白(HbA1c)、空腹及餐后2 h C肽等生化指标.测定双眼屈光度、角膜曲率、前房深度、晶状体厚度等,并在降糖治疗的第1、2、3、4周分别复测以上眼部指标.分析屈光度改变与各生化指标的相关性及降糖治疗前后各眼部指标的变化.结果 降糖治疗后所有患者均出现远视性屈光改变,平均最大远视改变幅度1.6 D(0.50 D～3.20 D),改变幅度与HbA1c、治疗第1周的降糖速度呈正相关(r值分别为0.84,0.53;P值均＜0.05),与治疗前随机血糖、空腹及餐后2 h C肽无相关性,持续约2～4周逐渐恢复治疗前屈光水平.治疗前后角膜曲率、前房深度、晶状体厚度等眼部指标未见显著性变化.结论 降糖治疗导致糖尿病患者出现暂时性远视改变,改变幅度主要与治疗前HbA1c水平及治疗的前7天的降糖速度有关.其发生机制可能与晶状体水合化导致的屈光力降低有关,而非晶状体形态的改变.

abstractsObjective To evaluate effects of glycemic control on refraction in diabetic patients.Methods Twenty newly diagnosed diabetic patients were included in this study. The random blood glucose,glycosylated hemoglobin A1c( HbA1c) levels, fasting C-peptide and postprandial 2 h C-peptide levels were measured before treatment. The patients with random blood glucose ≥ 12. 0 mmol/L and HbA1c ≥ 10. 0%were selected. Refraction, intraocular pressure, radius of the anterior corneal curvature, depth of the anterior chamber, lens thickness, vitreous length, and axial length were measured on admission and at the end of week 1,2, 3 and 4 during glycaemic control. Results A transient hyperopic change occurred in all the patients receiving glycemic control with a mean maximum hyperopic changes of 1.6 D ( 0. 50 D ～ 3.20 D). There was a positive correlation between the magnitude of the maximum hyperopic changes and the HbA1 c levels on admission ( r = 0.84, P ＜ 0.05 ). There was a positive correlation between the magnitude of the maximum hyperopic changes and the daily rate of blood glucose reduction over the first 7 days of the treatment ( r = 0.53, P ＜ 0.05 ). There was no significant correlation between the magnitude of the maximum hyperopic changes and the levels of random blood glucose on admission. No significant correlation was observed between the maximum hyperopic changes and fasting C-peptide or postprandial 2 h C-peptide.There were no significant correlations between the magnitude of the maximum hyperopic changes and age,blood press, body mass index, triglyceride, total cholesterol, low-density lipoprotein or high-density lipoprotein. No significant changes were observed in the intraocular pressure, radius of the anterior corneal curvature, depth of the anterior chamber, lens thickness, vitreous length and axial length during glycemic control. Conclusions Transient hyperopic changes occur after glycemic control in diabetic patients with severe hyperglycaemia. The degrees of transient hyperopia are highly dependent on HbA1c levels before treatment and the rate of reduction of glucose level over the first 7 days of treatment. This is probably due to the decrease of refractive power by lens hydration, not morphological change of lens.