Department of Endocrinology, Beijing Hospital, Nations Center of Gerontology, Beijing, China.
Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, P.R.China, Beijing, China.
BMC Ophthalmol. 2021 May 17;21(1):220. doi: 10.1186/s12886-021-01975-7.
To investigate the changes in retinal nerve fiber layer thickness and macular blood flow density during the preclinical stage of diabetic retinopathy and their relationship with blood glucose.
In this cross-sectional study, 97 diabetic patients (total of 188 eyes; 144 eyes in no diabetic retinopathy group, 44 eyes in mild diabetic non-proliferative retinopathy group) and 35 healthy people (70 eyes) were enrolled, All the subjects were divided into different groups based on their HbA1c levels, and they underwent optical coherence tomography angiography. We compared the optical coherence tomography angiography parameters and retinal nerve fiber layer thickness among the different glucose groups.
The parafoveal vessel density and the temporal retinal nerve fiber layer thickness were lower (p < 0.05) in the diabetic group than in the normal group. The diabetic group showed a higher acircularity index than the normal group. The normal group had the highest vessel density and the lowest acircularity index, followed by the no-diabetic retinopathy group and the mild non-proliferative retinopathy group, (p < 0.001). Foveal vascular density and parafoveal vessel density decreased with an increase in HbA1c. There was a negative correlation between parafoveal vessel density in the deep retinal vascular layer and fasting blood glucose (p < 0.01). The temporal retinal nerve fiber layer thickness decreased across the HbA1c level groups, and was positively correlated with the parafoveal vessel density in the superficial retinal vascular layer (p < 0.05).
This study shows that retinal microvasculopathy and neuropathy can be present in the absence of retinopathy. The vessel density of the deep retinal vascular layer was negatively correlated with fasting blood glucose, and the temporal retinal nerve fiber layer thickness was positively correlated with the vessel density of the superficial retinal vascular layer. These indicators are helpful for endocrinologists and ophthalmologists in detecting early diabetic retinal pathological lesions.
研究糖尿病视网膜病变临床前期视网膜神经纤维层厚度和黄斑血流密度的变化及其与血糖的关系。
本横断面研究纳入了 97 例糖尿病患者（共 188 只眼；无糖尿病视网膜病变组 144 只眼，轻度非增生性糖尿病视网膜病变组 44 只眼）和 35 名健康人（70 只眼）。所有受试者均根据糖化血红蛋白（HbA1c）水平分为不同组，并进行光学相干断层扫描血管造影检查。比较不同血糖组间光学相干断层扫描血管造影参数和视网膜神经纤维层厚度。
与正常组相比，糖尿病组患者的中心凹旁血管密度和颞侧视网膜神经纤维层厚度较低（p<0.05），糖尿病组的环形度指数较高。正常组的血管密度最高，环形度指数最低，其次是无糖尿病视网膜病变组和轻度非增生性糖尿病视网膜病变组（p<0.001）。随着 HbA1c 的增加，中心凹血管密度和中心凹旁血管密度逐渐降低。深层视网膜血管层的中心凹旁血管密度与空腹血糖呈负相关（p<0.01）。颞侧视网膜神经纤维层厚度随 HbA1c 水平组的变化而降低，且与浅层视网膜血管层的中心凹旁血管密度呈正相关（p<0.05）。
本研究表明，在没有视网膜病变的情况下，可能已经存在视网膜微血管病变和神经病变。深层视网膜血管层的血管密度与空腹血糖呈负相关，颞侧视网膜神经纤维层厚度与浅层视网膜血管层的血管密度呈正相关。这些指标有助于内分泌科医生和眼科医生检测早期糖尿病视网膜病变。
