PURPOSE To investigate microvascular abnormalities in diabetic patients without conventional clinical signs of diabetic retinopathy (DR). METHODS In this cross-sectional observational cohort study, the study group included randomly chosen participants of a community-based cohort with diabetes type 2 without DR, and the control group consisted of non-diabetic individuals from a population-based study. All participants underwent optical coherence tomographic angiography (OCTA). RESULTS Upon OCTA, 118 (40.4%) eyes of the study group (n = 292 eyes) showed microvascular abnormalities including foveal avascular zone erosion (95 (32.5%) eyes), non-perfusion areas in the superficial and deep retinal layers (39 (13.4%) eyes and 19 (6.5%) eyes, respectively), and microaneurysms in the superficial and deep retinal layers (22 (7.5%) eyes and 31 (10.6%) eyes, resp.). None of these abnormalities was detected in the control group (n = 80). The study group showed a lower vessel density in the superficial retinal vascular layer in all regions except for the foveal region (P < 0.001), and higher vessel density in the parafoveal region in the deep retinal vascular layer (P = 0.01). Higher diabetes prevalence was associated with lower superficial retinal vascular density (P = 0.005) in multivariable analysis. A lower radial peripapillary capillary flow density was correlated (regression coefficient r, 0.62) with higher fasting blood concentration of glucose (P < 0.001) in multivariable analysis. CONCLUSIONS OCTA revealed microvascular abnormalities in 40% of eyes of diabetic patients without ophthalmoscopically detectable diabetic fundus changes in a community-based population. The early stage of DR may be re-defined upon OCTA.

中文翻译：

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通过光学相干断层扫描血管造影术检测到的糖尿病前期视网膜病变中的微血管视网膜变化。

目的探讨无常规糖尿病视网膜病变（DR）临床症状的糖尿病患者的微血管异常情况。方法在这项横断面观察性队列研究中，研究组包括随机选择的2型糖尿病无DR社区参与者的对照组，对照组由基于人群的研究的非糖尿病患者组成。所有参与者均进行了光学相干断层扫描血管造影（OCTA）。结果OCTA后，研究组的118眼（40.4％）（n = 292眼）表现出微血管异常，包括中央凹无血管区域糜烂（95（32.5％）眼），浅层和深层视网膜的非灌注区域（39） （分别为13.4％）和19（6.5％）眼，以及浅表和深层视网膜微动脉瘤（22（7.5％）眼和31（10.6％）眼，分别）。在对照组中未检测到这些异常（n = 80）。研究组显示除中央凹区以外的所有区域，浅表视网膜血管层的血管密度较低（P <0.001），而在深视网膜血管层的中央凹旁区域的血管密度较高（P = 0.01）。在多变量分析中，较高的糖尿病患病率与较低的浅表视网膜血管密度相关（P = 0.005）。在多变量分析中，较低的放射状乳头周围毛细血管血流密度（回归系数r，0.62）与较高的空腹血糖浓度（P <0.001）相关。结论OCTA显示在社区人群中40％的糖尿病患者的眼中微血管异常，而在眼底镜下无法检测到的糖尿病眼底改变。